| | | | | | | | | | | | | | | | | | | | | |
<?xml version="1.0" encoding="windows-1252"?> |
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xbrldt="http://xbrl.org/2005/xbrldt"> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/> |
| <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#DocumentandEntityInformation" roleURI="http://www.idt.net/role/DocumentandEntityInformation"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#ConsolidatedBalanceSheets" roleURI="http://www.idt.net/role/ConsolidatedBalanceSheets"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#ConsolidatedBalanceSheetsParenthetical" roleURI="http://www.idt.net/role/ConsolidatedBalanceSheetsParenthetical"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#ZedgeSpinOffDetails" roleURI="http://www.idt.net/role/ZedgeSpinOffDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#InvestmentincornerstonepharmaceuticalsincDetails" roleURI="http://www.idt.net/role/InvestmentincornerstonepharmaceuticalsincDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#MarketableSecuritiesDetails" roleURI="http://www.idt.net/role/MarketableSecuritiesDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#MarketableSecuritiesDetails2" roleURI="http://www.idt.net/role/MarketableSecuritiesDetails2"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#MarketableSecuritiesDetailsTextual" roleURI="http://www.idt.net/role/MarketableSecuritiesDetailsTextual"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#FairValueMeasurementsDetails" roleURI="http://www.idt.net/role/FairValueMeasurementsDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#EquityDetails" roleURI="http://www.idt.net/role/EquityDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#EquityDetailsTextual" roleURI="http://www.idt.net/role/EquityDetailsTextual"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#RevolvingCreditLoanPayableDetails" roleURI="http://www.idt.net/role/RevolvingCreditLoanPayableDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#AccruedSeveranceExpenseDetails" roleURI="http://www.idt.net/role/AccruedSeveranceExpenseDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#AccumulatedOtherComprehensiveLossDetails" roleURI="http://www.idt.net/role/AccumulatedOtherComprehensiveLossDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#BusinessSegmentInformationDetails" roleURI="http://www.idt.net/role/BusinessSegmentInformationDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#CommitmentsAndContingenciesDetails" roleURI="http://www.idt.net/role/CommitmentsAndContingenciesDetails"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#CommitmentsAndContingenciesDetailsTextual" roleURI="http://www.idt.net/role/CommitmentsAndContingenciesDetailsTextual"/> |
| <roleRef xlink:type="simple" xlink:href="idt-20170131.xsd#IncomeTaxesDetails" roleURI="http://www.idt.net/role/IncomeTaxesDetails"/> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/DocumentandEntityInformation"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_StatementTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_1" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassAMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassBMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_EntityRegistrantName_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_EntityCentralIndexKey_7" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_AmendmentFlag_8" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_CurrentFiscalYearEndDate_9" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_DocumentType_10" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_DocumentPeriodEndDate_11" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_DocumentFiscalYearFocus_12" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_DocumentFiscalPeriodFocus_13" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_EntityFilerCategory_14" order="90" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_15" order="100" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/ConsolidatedBalanceSheets"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_StatementTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_1" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassAMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassBMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_AssetsAbstract_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_AssetsCurrentAbstract_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_8" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_9" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_10" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReceivablesNetCurrent" xlink:label="loc_us-gaap_ReceivablesNetCurrent_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_ReceivablesNetCurrent_11" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="loc_us-gaap_PrepaidExpenseCurrent_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_PrepaidExpenseCurrent_12" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_OtherAssetsCurrent_13" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_7" xlink:to="loc_us-gaap_AssetsCurrent_14" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_15" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_Goodwill_16" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_17" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermInvestments" xlink:label="loc_us-gaap_LongTermInvestments_18"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_LongTermInvestments_18" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_19"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_19" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_20"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_20" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_21"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6" xlink:to="loc_us-gaap_Assets_21" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_23"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_23" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_24"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_AccountsPayableCurrent_24" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_25"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_25" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent_26"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_DeferredRevenueCurrent_26" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerDepositsCurrent" xlink:label="loc_us-gaap_CustomerDepositsCurrent_27"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_CustomerDepositsCurrent_27" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_28"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_28" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_29"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_29" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_30"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_23" xlink:to="loc_us-gaap_LiabilitiesCurrent_30" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_31"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_31" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_32"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_Liabilities_32" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_33"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_CommitmentsAndContingencies_33" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_34"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_StockholdersEquityAbstract_34" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_35"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_PreferredStockValue_35" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_36"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_CommonStockValue_36" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_37"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_AdditionalPaidInCapital_37" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_us-gaap_TreasuryStockValue_38"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_TreasuryStockValue_38" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_39"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_39" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_40"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_40" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_41"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_34" xlink:to="loc_us-gaap_StockholdersEquity_41" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinorityInterest" xlink:label="loc_us-gaap_MinorityInterest_42"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_MinorityInterest_42" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_43"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_43" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_44"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_22" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_44" order="70" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/ConsolidatedBalanceSheetsParenthetical"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_StatementTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_1" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassAMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassBMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_7" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_8" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_PreferredStockSharesIssued_9" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_10" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_11" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_CommonStockSharesIssued_12" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_13" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="loc_us-gaap_TreasuryStockShares_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_TreasuryStockShares_14" order="90" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/ZedgeSpinOffDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable" xlink:label="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0" xlink:to="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_1" xlink:to="loc_dei_LegalEntityAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2" xlink:to="loc_dei_EntityDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2" xlink:to="loc_dei_EntityDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ZedgeMember" xlink:label="loc_idt_ZedgeMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_3" xlink:to="loc_idt_ZedgeMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItem" xlink:label="loc_idt_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItem_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0" xlink:to="loc_idt_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItem_6" order="20" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/InvestmentincornerstonepharmaceuticalsincDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InvestmentHoldingsLineItems" xlink:label="loc_us-gaap_InvestmentHoldingsLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InvestmentHoldingsLineItems_0" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentAxis" xlink:label="loc_invest_InvestmentAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_1" xlink:to="loc_invest_InvestmentAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_invest_InvestmentAxis_2" xlink:to="loc_invest_InvestmentDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentDomain" xlink:label="loc_invest_InvestmentDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_invest_InvestmentAxis_2" xlink:to="loc_invest_InvestmentDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_CornerstonePharmaceuticalsIncMember" xlink:label="loc_idt_CornerstonePharmaceuticalsIncMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentDomain_3" xlink:to="loc_idt_CornerstonePharmaceuticalsIncMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_CsPharmaHoldingsMember" xlink:label="loc_idt_CsPharmaHoldingsMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_invest_InvestmentDomain_3" xlink:to="loc_idt_CsPharmaHoldingsMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConvertibleDebtMember" xlink:label="loc_us-gaap_ConvertibleDebtMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7" xlink:to="loc_us-gaap_ConvertibleDebtMember_8" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConvertibleNotesPayableMember" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_9" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ConvertiblePromissoryNoteMember" xlink:label="loc_idt_ConvertiblePromissoryNoteMember_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7" xlink:to="loc_idt_ConvertiblePromissoryNoteMember_10" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_1" xlink:to="loc_us-gaap_TitleOfIndividualAxis_11" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_11" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_11" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_HowardAndDeborahJonasMember" xlink:label="loc_idt_HowardAndDeborahJonasMember_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12" xlink:to="loc_idt_HowardAndDeborahJonasMember_13" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_HowardSAndDeborahJonasFoundationMember" xlink:label="loc_idt_HowardSAndDeborahJonasFoundationMember_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12" xlink:to="loc_idt_HowardSAndDeborahJonasFoundationMember_14" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_JonasMember" xlink:label="loc_idt_JonasMember_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_12" xlink:to="loc_idt_JonasMember_15" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract" xlink:label="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentHoldingsLineItems_0" xlink:to="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InitialAmountOfInvestment" xlink:label="loc_idt_InitialAmountOfInvestment_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_InitialAmountOfInvestment_17" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_18"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_18" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_19"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_19" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_20"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_20" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_RemainingAmountOfInvestment" xlink:label="loc_idt_RemainingAmountOfInvestment_21"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_RemainingAmountOfInvestment_21" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_PurchaseSharesOfCapitalStock" xlink:label="loc_idt_PurchaseSharesOfCapitalStock_22"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_PurchaseSharesOfCapitalStock_22" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ExerciseWarrantsValue" xlink:label="loc_idt_ExerciseWarrantsValue_23"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_ExerciseWarrantsValue_23" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InitialAmountOfInvestmentAmountsPaid" xlink:label="loc_idt_InitialAmountOfInvestmentAmountsPaid_24"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_InitialAmountOfInvestmentAmountsPaid_24" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature" xlink:label="loc_us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature_25"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature_25" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_MaximumAmountToBeInvested" xlink:label="loc_idt_MaximumAmountToBeInvested_26"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_MaximumAmountToBeInvested_26" order="90" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentRepurchaseAgreementAmountToBeReceived" xlink:label="loc_invest_InvestmentRepurchaseAgreementAmountToBeReceived_27"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_invest_InvestmentRepurchaseAgreementAmountToBeReceived_27" order="100" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ProceedsFromIssuanceOfMemberInterests" xlink:label="loc_idt_ProceedsFromIssuanceOfMemberInterests_28"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_ProceedsFromIssuanceOfMemberInterests_28" order="110" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_InvestmentWarrantsExpirationDate" xlink:label="loc_invest_InvestmentWarrantsExpirationDate_29"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_invest_InvestmentWarrantsExpirationDate_29" order="120" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLongTermInvestments" xlink:label="loc_us-gaap_OtherLongTermInvestments_30"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_OtherLongTermInvestments_30" order="130" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:label="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_31"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_31" order="140" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_32"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_32" order="150" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_OtherCurrentLiabilities" xlink:label="loc_idt_OtherCurrentLiabilities_33"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_OtherCurrentLiabilities_33" order="160" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ProceedsFromThirdPartyMemberInterestsDescription" xlink:label="loc_idt_ProceedsFromThirdPartyMemberInterestsDescription_34"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_ProceedsFromThirdPartyMemberInterestsDescription_34" order="170" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InvestmentWarrantsExerciseTermsAndExpiration" xlink:label="loc_idt_InvestmentWarrantsExerciseTermsAndExpiration_35"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_InvestmentWarrantsExerciseTermsAndExpiration_35" order="180" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConvertibleNotesPayable" xlink:label="loc_us-gaap_ConvertibleNotesPayable_36"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_ConvertibleNotesPayable_36" order="190" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_PercentageOfDirectAndIndirectInterest" xlink:label="loc_idt_PercentageOfDirectAndIndirectInterest_37"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_idt_PercentageOfDirectAndIndirectInterest_37" order="200" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromSaleOfInterestInCorporateUnit" xlink:label="loc_us-gaap_ProceedsFromSaleOfInterestInCorporateUnit_38"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_InvestmentInCornerstonePharmaceuticalsIncTextualAbstract_16" xlink:to="loc_us-gaap_ProceedsFromSaleOfInterestInCorporateUnit_38" order="210" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/MarketableSecuritiesDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_CertificatesOfDepositMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FederalHomeLoanBankCertificatesAndObligationsFHLBMember" xlink:label="loc_us-gaap_FederalHomeLoanBankCertificatesAndObligationsFHLBMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_FederalHomeLoanBankCertificatesAndObligationsFHLBMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember" xlink:label="loc_us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember_6" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember_7" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InternationalAgencyNotesMember" xlink:label="loc_idt_InternationalAgencyNotesMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_idt_InternationalAgencyNotesMember_8" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_MutualFundsMember" xlink:label="loc_idt_MutualFundsMember_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_idt_MutualFundsMember_9" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateBondSecuritiesMember" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_10" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquitySecuritiesMember" xlink:label="loc_us-gaap_EquitySecuritiesMember_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_EquitySecuritiesMember_11" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USTreasuryNotesSecuritiesMember" xlink:label="loc_us-gaap_USTreasuryNotesSecuritiesMember_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_USTreasuryNotesSecuritiesMember_12" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MunicipalBondsMember" xlink:label="loc_us-gaap_MunicipalBondsMember_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_MunicipalBondsMember_13" order="90" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesCurrentAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_15" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_16" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_17" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedGainBeforeTax_18"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedGainBeforeTax_18" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedLossBeforeTax_19"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_AvailableForSaleEquitySecuritiesAccumulatedGrossUnrealizedLossBeforeTax_19" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_AvailableForSaleSecuritiesTotalGrossUnrealizedGains" xlink:label="loc_idt_AvailableForSaleSecuritiesTotalGrossUnrealizedGains_20"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_idt_AvailableForSaleSecuritiesTotalGrossUnrealizedGains_20" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_AvailableForSaleSecuritiesTotalGrossUnrealizedLosses" xlink:label="loc_idt_AvailableForSaleSecuritiesTotalGrossUnrealizedLosses_21"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_idt_AvailableForSaleSecuritiesTotalGrossUnrealizedLosses_21" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_22"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesCurrentAbstract_14" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_22" order="70" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/MarketableSecuritiesDetails2"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_2" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_CertificatesOfDepositMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InternationalAgencyNotesMember" xlink:label="loc_idt_InternationalAgencyNotesMember_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_idt_InternationalAgencyNotesMember_6" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_MutualFundsMember" xlink:label="loc_idt_MutualFundsMember_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_idt_MutualFundsMember_7" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateBondSecuritiesMember" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_8" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_9" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MunicipalBondsMember" xlink:label="loc_us-gaap_MunicipalBondsMember_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_MunicipalBondsMember_10" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquitySecuritiesMember" xlink:label="loc_us-gaap_EquitySecuritiesMember_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_3" xlink:to="loc_us-gaap_EquitySecuritiesMember_11" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_12" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_13" order="20" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/MarketableSecuritiesDetailsTextual"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1" xlink:to="loc_dei_LegalEntityAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2" xlink:to="loc_dei_EntityDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2" xlink:to="loc_dei_EntityDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ZedgeMember" xlink:label="loc_idt_ZedgeMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_3" xlink:to="loc_idt_ZedgeMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_MarketableSecuritiesTextualAbstract" xlink:label="loc_idt_MarketableSecuritiesTextualAbstract_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_0" xlink:to="loc_idt_MarketableSecuritiesTextualAbstract_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_NumberOfRelatedPartySharesReceivedInConnectionWithRestrictedStock" xlink:label="loc_idt_NumberOfRelatedPartySharesReceivedInConnectionWithRestrictedStock_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_idt_NumberOfRelatedPartySharesReceivedInConnectionWithRestrictedStock_6" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_AmountPaidForRelatedPartySharesReceivedInConnectionWithRestrictedStock" xlink:label="loc_idt_AmountPaidForRelatedPartySharesReceivedInConnectionWithRestrictedStock_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_idt_AmountPaidForRelatedPartySharesReceivedInConnectionWithRestrictedStock_7" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InvestmentOwnedAtFairValue" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_8" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_9" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedGains" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_10" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_MarketableSecuritiesTextualAbstract_5" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_11" order="50" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/FairValueMeasurementsDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_0" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_3" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_8" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_9" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_0" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_10" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_10" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_11" order="0" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/EquityDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_StatementTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_1" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2" xlink:to="loc_us-gaap_EquityComponentDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2" xlink:to="loc_us-gaap_EquityComponentDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ParentMember" xlink:label="loc_us-gaap_ParentMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3" xlink:to="loc_us-gaap_ParentMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:label="loc_us-gaap_NoncontrollingInterestMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3" xlink:to="loc_us-gaap_NoncontrollingInterestMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsCash" xlink:label="loc_us-gaap_DividendsCash_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_us-gaap_DividendsCash_8" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_RepurchaseOfRestrictedStock" xlink:label="loc_idt_RepurchaseOfRestrictedStock_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_idt_RepurchaseOfRestrictedStock_9" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_10" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_11" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_DistributionToNoncontrollingInterests" xlink:label="loc_idt_DistributionToNoncontrollingInterests_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_idt_DistributionToNoncontrollingInterests_12" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_StockBasedCompensation" xlink:label="loc_idt_StockBasedCompensation_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_idt_StockBasedCompensation_13" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_14" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_14" xlink:to="loc_us-gaap_ProfitLoss_15" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_14" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_16" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_14" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_17" order="20" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/EquityDetailsTextual"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_1" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2" xlink:to="loc_us-gaap_ClassOfStockDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassAMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3" xlink:to="loc_us-gaap_CommonClassBMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_1" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_6" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_7_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_6" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_7_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_7" xlink:to="loc_us-gaap_SubsequentEventMember_8" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_1" xlink:to="loc_us-gaap_TitleOfIndividualAxis_9" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_9" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_10" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_10_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_9" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_10_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_EmployeeMember" xlink:label="loc_idt_EmployeeMember_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_10" xlink:to="loc_idt_EmployeeMember_11" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_DividendsCommonStockCash_12" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_13" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsPayableAmountPerShare" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_14" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_15" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_16" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased" xlink:label="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_17" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased_18"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased_18" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_19"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_19" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_20"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_20" order="90" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_21"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_21" order="100" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_22"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_22" order="110" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_23"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_23" order="120" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/RevolvingCreditLoanPayableDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_DebtInstrumentTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_2" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_2" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_JulyTwelveTwoThousandTwelveMember" xlink:label="loc_idt_JulyTwelveTwoThousandTwelveMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_3" xlink:to="loc_idt_JulyTwelveTwoThousandTwelveMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrimeRateMember" xlink:label="loc_us-gaap_PrimeRateMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_3" xlink:to="loc_us-gaap_PrimeRateMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_6" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_6" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_7_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_6" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_7_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_7" xlink:to="loc_us-gaap_LineOfCreditMember_8" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_9" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_10" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:label="loc_us-gaap_LineOfCreditFacilityExpirationDate1_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_LineOfCreditFacilityExpirationDate1_11" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermBankLoansAndNotesPayable" xlink:label="loc_us-gaap_ShortTermBankLoansAndNotesPayable_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_ShortTermBankLoansAndNotesPayable_12" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_13" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_LineOfCreditCovenantMaximumAmountOfLoansAndAdvancesToAffiliatesOrSubsidiaries" xlink:label="loc_idt_LineOfCreditCovenantMaximumAmountOfLoansAndAdvancesToAffiliatesOrSubsidiaries_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_idt_LineOfCreditCovenantMaximumAmountOfLoansAndAdvancesToAffiliatesOrSubsidiaries_14" order="60" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_InvestmentsInAndAdvancesToAffiliates" xlink:label="loc_idt_InvestmentsInAndAdvancesToAffiliates_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_idt_InvestmentsInAndAdvancesToAffiliates_15" order="70" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_LineOfCreditUtilizedForLettersOfCreditOutstandingAmount" xlink:label="loc_idt_LineOfCreditUtilizedForLettersOfCreditOutstandingAmount_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_idt_LineOfCreditUtilizedForLettersOfCreditOutstandingAmount_16" order="80" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDescription_17"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDescription_17" order="90" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_BasisPointsSpread" xlink:label="loc_idt_BasisPointsSpread_18"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0" xlink:to="loc_idt_BasisPointsSpread_18" order="100" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/AccruedSeveranceExpenseDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2" xlink:to="loc_us-gaap_SegmentDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_2" xlink:to="loc_us-gaap_SegmentDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_WorkforceReductionMember" xlink:label="loc_idt_WorkforceReductionMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3" xlink:to="loc_idt_WorkforceReductionMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_SeveranceExpenseTextualAbstract" xlink:label="loc_idt_SeveranceExpenseTextualAbstract_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_idt_SeveranceExpenseTextualAbstract_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SeveranceCosts1" xlink:label="loc_us-gaap_SeveranceCosts1_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_SeveranceExpenseTextualAbstract_5" xlink:to="loc_us-gaap_SeveranceCosts1_6" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_SeveranceExpenseTextualAbstract_5" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_7" order="10" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/AccumulatedOtherComprehensiveLossDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2" xlink:to="loc_us-gaap_EquityComponentDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2" xlink:to="loc_us-gaap_EquityComponentDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_6" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_7" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_8" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_9" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_10" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_11" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_12" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_13" order="40" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/BusinessSegmentInformationDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1" xlink:to="loc_us-gaap_ConsolidationItemsAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_2" xlink:to="loc_us-gaap_ConsolidationItemsDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_2" xlink:to="loc_us-gaap_ConsolidationItemsDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_3" xlink:to="loc_us-gaap_OperatingSegmentsMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5" xlink:to="loc_us-gaap_SegmentDomain_6" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_6_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5" xlink:to="loc_us-gaap_SegmentDomain_6_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_TelecomPlatformServicesMember" xlink:label="loc_idt_TelecomPlatformServicesMember_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6" xlink:to="loc_idt_TelecomPlatformServicesMember_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_UnifiedCommunicationsAsServiceMember" xlink:label="loc_idt_UnifiedCommunicationsAsServiceMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6" xlink:to="loc_idt_UnifiedCommunicationsAsServiceMember_8" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ConsumerPhoneServicesMember" xlink:label="loc_idt_ConsumerPhoneServicesMember_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6" xlink:to="loc_idt_ConsumerPhoneServicesMember_9" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_AllOtherMember" xlink:label="loc_idt_AllOtherMember_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6" xlink:to="loc_idt_AllOtherMember_10" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateMember" xlink:label="loc_us-gaap_CorporateMember_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6" xlink:to="loc_us-gaap_CorporateMember_11" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_us-gaap_Revenues_12" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_us-gaap_OperatingIncomeLoss_13" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherGeneralExpense" xlink:label="loc_us-gaap_OtherGeneralExpense_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0" xlink:to="loc_us-gaap_OtherGeneralExpense_14" order="30" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/CommitmentsAndContingenciesDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable" xlink:label="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_0" xlink:to="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_1" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_2" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_IDTFinancialServicesCustomerDepositsMember" xlink:label="loc_idt_IDTFinancialServicesCustomerDepositsMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3" xlink:to="loc_idt_IDTFinancialServicesCustomerDepositsMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_RelatedLettersOfCreditMember" xlink:label="loc_idt_RelatedLettersOfCreditMember_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3" xlink:to="loc_idt_RelatedLettersOfCreditMember_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_RestrictedOtherMember" xlink:label="loc_idt_RestrictedOtherMember_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_3" xlink:to="loc_idt_RestrictedOtherMember_6" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_0" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_7" order="10" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/CommitmentsAndContingenciesDetailsTextual"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_0" xlink:to="loc_us-gaap_LossContingenciesTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_1" xlink:to="loc_us-gaap_StatementScenarioAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_2" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_2" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ExpirationDateOneMember" xlink:label="loc_idt_ExpirationDateOneMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_3" xlink:to="loc_idt_ExpirationDateOneMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_1" xlink:to="loc_dei_LegalEntityAxis_5" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_6"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_5" xlink:to="loc_dei_EntityDomain_6" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_6_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_5" xlink:to="loc_dei_EntityDomain_6_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_IdtFinancialServicesLtdMember" xlink:label="loc_idt_IdtFinancialServicesLtdMember_7"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_6" xlink:to="loc_idt_IdtFinancialServicesLtdMember_7" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_IdtPaymentServicesAndIdtFinancialServicesLtdMember" xlink:label="loc_idt_IdtPaymentServicesAndIdtFinancialServicesLtdMember_8"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_6" xlink:to="loc_idt_IdtPaymentServicesAndIdtFinancialServicesLtdMember_8" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_CommitmentsAndContingenciesTextualAbstract" xlink:label="loc_idt_CommitmentsAndContingenciesTextualAbstract_9"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_0" xlink:to="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PurchaseObligation" xlink:label="loc_us-gaap_PurchaseObligation_10"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_us-gaap_PurchaseObligation_10" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_11"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_11" order="10" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_LettersOfCreditExpirationDate" xlink:label="loc_idt_LettersOfCreditExpirationDate_12"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_idt_LettersOfCreditExpirationDate_12" order="20" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_PerformanceBondsOutstanding" xlink:label="loc_idt_PerformanceBondsOutstanding_13"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_idt_PerformanceBondsOutstanding_13" order="30" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerDepositsCurrent" xlink:label="loc_us-gaap_CustomerDepositsCurrent_14"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_us-gaap_CustomerDepositsCurrent_14" order="40" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_CashAndCashEquivalentsSubstantiallyRestricted" xlink:label="loc_idt_CashAndCashEquivalentsSubstantiallyRestricted_15"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_idt_CashAndCashEquivalentsSubstantiallyRestricted_15" order="50" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherGeneralExpense" xlink:label="loc_us-gaap_OtherGeneralExpense_16"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_idt_CommitmentsAndContingenciesTextualAbstract_9" xlink:to="loc_us-gaap_OtherGeneralExpense_16" order="60" use="optional"/> |
| | </definitionLink> |
| <definitionLink xlink:type="extended" xlink:role="http://www.idt.net/role/IncomeTaxesDetails"> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxContingencyLineItems" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_0"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxContingencyTable" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_1"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_0" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_1" order="0" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_2"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_1" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_2" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_3"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_2" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_3" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_3_Default"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_2" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_3_Default" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="idt-20170131.xsd#idt_ElmionNetherlandsBvMember" xlink:label="loc_idt_ElmionNetherlandsBvMember_4"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_3" xlink:to="loc_idt_ElmionNetherlandsBvMember_4" order="0" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_5"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_0" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_5" order="10" use="optional"/> |
| | </definitionLink> |
| </linkbase> |