ETSI ETS 300 392-10-4 ed.2 (2000-02)

Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 10: Supplementary services stage 1; Sub-part 4: Call Forwarding (CF)

RE/TETRA-03001-10-04

Radijska oprema in sistemi (RES) - Vseevropski prizemni snopovni radio (TETRA) - Govor in podatki (V+D) - 10. del: Dopolnilne storitve stopnje 1- 10-04. del: Izsmeritev klica

General Information

• Status: Published
• Publication Date: 23-Feb-2000
• Technical Committee: TCCE 3 - TCCE Air Interface and Network Protocols
• Current Stage: 13 - TB decision to make document historical
• Due Date: 23-Feb-2004
• Completion Date: 23-Feb-2004
• Mandate: T-172-1A
• Ref Project: SIST ETS 300 392-10-4 E2:2003 - Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 10: Supplementary services stage 1; Sub-part 4: Call Forwarding (CF)

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Radijska oprema in sistemi (RES) - Vseevropski prizemni snopovni radio (TETRA) - Govor in podatki (V+D) - 10. del: Dopolnilne storitve stopnje 1- 10-04. del: Izsmeritev klicaTerrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 10: Supplementary services stage 1; Sub-part 4: Call Forwarding (CF)33.070.10Prizemni snopovni radio (TETRA)Terrestrial Trunked Radio (TETRA)ICS:Ta slovenski standard je istoveten z:ETS 300 392-10-4 Edition 2SIST ETS 300 392-10-4 E2:2003en01-december-2003SIST ETS 300 392-10-4 E2:2003SLOVENSKI
STANDARD



SIST ETS 300 392-10-4 E2:2003



EUROPEANETS300392-10-4TELECOMMUNICATIONFebruary2000STANDARDSecondEditionSource:TETRAReference:RE/TETRA-03001-10-04ICS:33.020Keywords:CF,data,radio,speech,stage1,supplementaryservice,TETRATerrestrialTrunkedRadio(TETRA);VoiceplusData(V+D);Part10:Supplementaryservicesstage1;Sub-part4:CallForwarding(CF)ETSIEuropeanTelecommunicationsStandardsInstituteETSISecretariatPostaladdress:F-06921SophiaAntipolisCEDEX-FRANCEOfficeaddress:650RoutedesLucioles-SophiaAntipolis-Valbonne-FRANCEInternet:[e-mail]-http://www.etsi.orgTel.:[phone]-Fax:[phone]CopyrightNotification:Nopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST ETS 300 392-10-4 E2:2003



Page2ETS300392-10-4:February2000Whilsteverycarehasbeentakeninthepreparationandpublicationofthisdocument,errorsincontent,typographicalorotherwise,mayoccur.Ifyouhavecommentsconcerningitsaccuracy,pleasewriteto"ETSIStandardsMakingSupportDept."attheaddressshownonthetitlepage.SIST ETS 300 392-10-4 E2:2003



Page3ETS300392-10-4:February2000ContentsForeword.71Scope.92Normativereferences.93Definitions,symbolsandabbreviations.103.1Definitions.103.2Symbols.123.3Abbreviations.123.3.1Supplementaryserviceabbreviations.124SS-CFGenericSpecification.124.1Description.134.1.1Generaldescription.134.1.2Applicability.134.2Procedures.134.2.1Provision/Withdrawal.134.2.2Normalprocedures.144.2.2.1Activation/deactivation/definition/registration/interrogation.144.2.2.1.1Activation/deactivation.144.2.2.1.2Enable/Disable.154.2.2.1.3Registration.164.2.2.1.4Interrogation.164.2.2.2Invocationandoperation.174.2.2.2.1Forwarded-touserCnotification.174.2.2.2.2CallinguserAnotification.174.2.3Exceptionalprocedures.184.2.3.1Activation/Deactivation.184.2.3.2Interrogation.184.2.3.3Invocationandoperation.194.3InteractionswithothersupplementaryservicesandANFs.194.3.1CallingLineIdentificationPresentation(SS-CLIP).194.3.2ConnectedLineIdentificationPresentation(SS-COLP).194.3.3Calling/ConnectedLineIdentificationRestriction(SS-CLIR/SS-COLR).194.3.4CallCompletiontoBusySubscriber(SS-CCBS).204.3.5CallCompletiononNoReply(SS-CCNRy).204.3.6Callreport.204.3.7Talkingpartyidentification.204.3.8Listsearchcall.204.3.9Shortnumberaddressing.204.3.10Areaselection.204.3.11Accesspriority.204.3.12Callwaiting.214.3.13Callhold.214.3.14Lateentry.214.3.15Transferofcontrol.214.3.16Prioritycall.214.3.17Pre-emptivePriorityCall.214.3.18Includecall.214.3.19Adviceofcharge.214.3.20Barringofoutgoingcalls.214.3.21Barringofincomingcalls.214.3.22Ambiancelistening.224.3.23Dynamicgroupnumberassignment.224.3.24InteractionwithANFMobility.224.4Inter-workingconsiderations.23SIST ETS 300 392-10-4 E2:2003



Page4ETS300392-10-4:February20005SS-CFoverallSDL.236SS-CFUSpecificSpecification.276.1Description.276.1.1Applicability.276.2InteractionwithothersupplementaryservicesandANFs.276.2.1CallWaitingSS-CW.276.2.2CallForwardingBusy(SS-CFB).276.2.3CallForwardingNoReply(SS-CFNRy).286.2.4CallForwardingnotReachable(SS-CFNRc).286.2.5Pre-emptivePriorityCall.286.2.6Callauthorizedbydispatcher.286.2.7Discreetlistening.287SS-CFBSpecificSpecification.287.1Description.287.1.1Generaldescription.287.1.2Applicability.287.2Procedures.297.2.1Provision/withdrawal.297.2.2Normalprocedures.297.2.2.1Activation/deactivation.297.3InteractionwithothersupplementaryservicesandANFs.297.3.1CallCompletiontoBusySubscriber(SS-CCBS).297.3.2CallCompletiononNoReply(SS-CCNR).297.3.3Pre-emptiveprioritycall.297.3.4CallForwardingUnconditional(SS-CFU).307.3.5CallForwardingNoReply(SS-CFNRy).307.3.6CallForwardingNotReachable(SS-CFNRc).307.3.7Callwaiting.307.3.8Discreetlistening.308SS-CFNRySpecificSpecification.308.1Description.318.1.1Generaldescription.318.1.2Applicability.318.2Procedures.318.2.1Provision/Withdrawal.318.2.2Normalprocedures.318.2.2.1Activation/Deactivation.318.2.2.2Invocationandoperation.318.2.3Exceptionalprocedures.318.2.3.1Activation/Deactivation.318.3InteractionwithothersupplementaryservicesandANFs.328.3.1CallCompletiontoBusySubscriber(SS-CCBS).328.3.2CallCompletiononNoReply(SS-CCNR).328.3.3CallForwardingUnconditional(SS-CFU).328.3.4CallForwardingBusy(SS-CFB).328.3.5CallForwardingNotReachable(SS-CFNRc).328.3.6Callauthorizedbydispatcher.328.3.7Callwaiting.328.3.8Pre-emptiveprioritycall.339SS-CFNRcSpecificSpecification.339.1Description.339.1.1Generaldescription.339.1.2Applicability.339.2Procedures.339.2.1Provision/withdrawal.339.2.2Normalprocedures.339.2.2.1Activation/deactivation/registration/interrogation.339.2.2.2Invocationandoperation.339.2.3Exceptionalprocedures.34SIST ETS 300 392-10-4 E2:2003



Page5ETS300392-10-4:February20009.2.3.1Activation/Deactivation.349.3InteractionswithothersupplementaryservicesandANFs.349.3.1Interactionswithothersupplementaryservices.349.3.2InteractionwithCallWaiting(SS-CW).349.3.3InteractionwithANFMobility.349.4Inter-workingconsiderations.3410SS-CFUforSDSSpecification.3410.1Description.3410.1.1Generaldescription.3410.1.2Applicability.3510.2Procedures.3510.2.1Provision/withdrawal.3510.2.2Normalprocedures.3510.2.2.1Activation/deactivation/registration/interrogation.3510.2.2.1.1Enable/Disable.3610.2.2.1.2Registration.3610.2.2.1.3Interrogation.3710.2.2.2Invocationandoperation.3710.2.3Exceptionalprocedures.3710.2.3.1Activation/Deactivation.3710.3InteractionswithothersupplementaryservicesandANFs.3710.3.1Interactionswithothersupplementaryservices.3710.3.2InteractionwithANFMobility.3710.4Inter-workingconsiderations.38AnnexA(informative):Bibliography.39History.40SIST ETS 300 392-10-4 E2:2003



Page6ETS300392-10-4:February2000BlankpageSIST ETS 300 392-10-4 E2:2003



Page7ETS300392-10-4:February2000ForewordThisEuropeanTelecommunicationStandard(ETS)hasbeenproducedbytheTerrestrialTrunkedRadio(TETRA)ProjectoftheEuropeanTelecommunicationsStandardsInstitute(ETSI).ThisETSisamulti-partstandardandwillconsistofthefollowingparts:Part1:"Generalnetworkdesign";Part2:"AirInterface(AI)";Part3:"InterworkingattheInter-SystemInterface(ISI)";Part4:"Gatewaysbasicoperation";Part5:"PeripheralEquipmentInterface(PEI)";Part6:"LineconnectedStation(LS)";Part7:"Security";Part9:"Generalrequirementsforsupplementaryservices";Part10:"Supplementaryservicesstage1";Part11:"Supplementaryservicesstage2";Part12:"Supplementaryservicesstage3";Part13:"SDLmodeloftheAirInterface(AI)";Part14:"ProtocolImplementationConformanceStatement(PICS)proformaspecification".TranspositiondatesDateofadoptionofthisETS:21January2000DateoflatestannouncementofthisETS(doa):30April2000DateoflatestpublicationofnewNationalStandardorendorsementofthisETS(dop/e):31October2000DateofwithdrawalofanyconflictingNationalStandard(dow):31October2000SIST ETS 300 392-10-4 E2:2003



Page8ETS300392-10-4:February2000BlankpageSIST ETS 300 392-10-4 E2:2003



Page9ETS300392-10-4:February20001ScopeThisETSspecifiesthesupplementaryservicesCallForwardingUnconditional(CFU),CallForwardingBusy(CFB),CallForwardingonNoReply(CFNRy)andCallForwardingonNotReachable(CFNRc)whichareapplicabletovariousbasicservicessupportedbyTETRASwMIs.BasicservicesarespecifiedinETS300392-2[4].SS-CFU,SS-CFB,SS-CFNRyandSS-CFNRcaresupplementaryserviceswhichapplyduringcallestablishmentprovidingaforwardingofanincomingcalltoanotherdestinationthantheoriginaldestinationdefinedbythecallinguserunderdifferentconditions(busy,noreplyornotreachable)orundernocondition(unconditional).Supplementaryservicesspecificationsareproducedinthreestages,accordingtothemethoddescribedinITU-TRecommendationI.210[2].Thepresentdocumentcontainsthestage1specificationsofSS-CFU,SS-CFB,SS-CFNRyandSS-CFNRc.Thestage1descriptionsspecifythesupplementaryservicesasseenbyusersofnetworks.ThisETSisapplicabletocircuitmodeTETRAV+Dtele-servicesandbearerservices.ThisETSisalsoapplicabletoTETRAShortDataService(SDS).ManMachineInterfacesandchargingprinciplesareoutsidethescopeofthisETS.SelectiveCallForwardingisoutsidethescopeofthisETS.NOTE1:SelectiveCallForwardingmaybeconsideredforfurtherimprovementsofTETRASS-CFatalaterstage.ThissecondeditionofthisETSwaspresentedasadeltadocumenttothefirsteditionofECMA-173[1].ThissecondeditionhasbeenredraftedbasedonthelatestpublishedtextofECMA-173[1]asaselfcontaineddocumentsoastobemorereadable.AdditionstoECMA-173[1]havebeenmadetotakeintoaccountparticularTETRAspecificssuchasgroupcallsandtoincludeuserrequirementsandsituationsnotaddressedinECMA-173[1].NOTE2:ContrarytoECMA-173[1],thisETSdoesnotspecifySS-CD(CallDeflection)whichisnotpresentlysupportedbyTETRA.NOTE3:ContrarytoECMA-173[1],thisETSdistinguishesbetweenNoReplyandNotReachablebecauseoftheradionatureoftheTETRAlinks.ThisStandardspecifiesalsotheForwardingCounter(FC),whichisapplicabletovariousbasicservicessupportedbyTETRANetworks.BasicservicesarespecifiedinETS300392-2[4].FCcountsthenumberofforwardingthatacallhasbeenforwardedandallowstolimitthenumberofforwardingthatacallrequestmayencounterduringcallestablishment,e.g.toprotectthenetworkagainstindefinitelooping.Thereisnouserinvolvedintheprovisionoroperationofforwardingcounter.2NormativereferencesThisETSincorporatesbydatedandundatedreference,provisionsfromotherpublications.Thesenormativereferencesarecitedattheappropriateplacesinthetextandthepublicationsarelistedhereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisETSonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthepublicationreferredtoapplies.[1]ECMA-173(1997):"PrivateIntegratedServicesNetwork(PISN)-Specification,FunctionalModelandInformationFlows-CallDiversionSupplementaryServices(CFSD)".[2]ITU-TRecommendationI.210(1993):"PrinciplesoftelecommunicationservicessupportedbyanISDNandthemeanstodescribethem".SIST ETS 300 392-10-4 E2:2003



Page10ETS300392-10-4:February2000[3]ITU-TRecommendationZ.100(1993):"CCITTSpecificationanddescriptionlanguage(SDL)".[4]ETS300392-2(1995):"TerrestrialEuropeanTrunkedRadio(TETRA);VoiceplusData(V+D);Part2:AirInterface(AI)".[5]CCITTRecommendationQ.9(1988):"Vocabularyofswitchingandsignallingterms".3Definitions,symbolsandabbreviations3.1DefinitionsForthepurposesofthisETS,thefollowingtermsanddefinitionsapply:Additionalnetworkfeature:additionalnetworkfeature(ANF)isacapability,overandabovethatofabasicservice,providedbyaSwMI,butnotdirectlytoaSwMIuser.Authorizeduser:userwhoisresponsibleforthedefinition,activationanddeactivationoftheservice.Theauthorizedusermayalsointerrogatetheservice.Affecteduser:userwhoissubjecttotheoperation.Busy:TETRAdestinationisconsideredtobebusyifeithera"networkdetermineduserbusy"ora"userdetermineduserbusy"conditionexists.Call,basiccall:callorbasiccallisaninstanceoftheuseofabasicservice.Connectednumber:numberoftheuserthatanswers(UserC).Forwarded-tonumber:forwarded-tonumberisthenumbertowhichacallisforwarded.Forwarded-touser:forwarded-touseristheusertowhichacallisforwarded.Forwarding:forwardingistheredirectionofacall,onbehalfofacalleduserandpriortoconnect,toanumberdifferentfromthenumberofthatcalleduser.Forwardingcause:forwardingcausecontainsthereasonfortheforwarding:CFU,CFB,CFNRy,CFNRc.Forwardingcounter:counterforthenumberofforwardinginvolvedinacallorsignallingconnectionduringtheestablishmentphase.Forwardingnumber:forwardingnumberisthenumberoftheserveduser.Forwardinguser:userforwhichthecallforwardingisinvoked;itmaybethecalleduserfirstandthenanyofthesuccessiveforwarded-tousers(seealsolastforwardinguser).Forwardswitching:networkrouteingalgorithmwhichperformstheforwardingbyjoiningtogetherthefirstconnectionfromUserA'snodetoUserB'snodeandasecond,newconnectionfromUserB'snodetoUserC'snode.Lastforwardinguser:lastforwardinguseristheserveduserfromthepointofviewoftheforwarded-touserforaparticularstageofcallforwarding.Inthecaseofacallsubjecttoasinglestageofcallforwarding,UserBisthelastforwardinguserfromthepointofviewofUserC.Inthecaseofacallsubjecttomultiplestagesofcallforwarding,userB1isthelastforwardinguserfromthepointofviewofuserB2,userB2isthelastforwardinguserfromthepointofviewofuserB3,etc.TheserveduserforthefinalstageofcallforwardingisthelastforwardinguserfromthepointofviewofUserC.LineStation(LS):physicalgroupingthatcontainsallthefixedequipmentthatisusedtoobtainTETRAservicesthroughaline.SIST ETS 300 392-10-4 E2:2003



Page11ETS300392-10-4:February2000MobileStation(MS):physicalgroupingthatcontainsallofthemobileequipmentthatisusedtoobtainTETRAservices.Bydefinition,amobilestationcontainsatleastoneMobileRadioStack(MRS).Originalcallednumber:originalcallednumberisthenumberofUserB(incaseofmultiplecallforwardinguserB1).Originalcalleduser:originalcalleduseristhefirstserveduserofacallwhichissubjecttooneormorestagesofcallforwarding,i.e.UserBorB1.Partialre-routeing:networkrouteingalgorithmwhichperformsthecallforwardingbyreplacingaparticularpartoftheconnectionfromUserA'snodetoUserB'snodebyanotherconnectionfromUserA'snodetoUserC'snode.Signallingconnection:connectionusedtoexchangeinformationbetweenpeersupplementaryserviceprotocolcontrolentitiesindependentlyofabasiccall.Supplementaryservice:anyserviceprovidedbyanetworkinadditiontoitsbasicserviceorservices(definedinCCITTRecommendationQ.9[5]).Asupplementaryservicemodifiesorsupplementsabasictelecommunicationservice.Consequently,itcannotbeofferedtoacustomerasastandaloneservice.Itmustbeofferedtogetherwithorinassociationwithabasictelecommunicationservice(extractfromITU-TRecommendationI.210[2]).SwitchingandManagementInfrastructure(SwMI):alloftheTETRAequipmentforaVoiceplusData(V+D)networkexceptforsubscriberterminals.TheSwMIenablessubscriberterminalstocommunicatewitheachotherviatheSwMI.SwMInumber:SwMInumberisanumberbelongingtoaSwMInumberingplan.Re-routeing:networkrouteingalgorithmwhichperformsthecallforwardingbyreplacingtheconnectionfromUserA'snodetoUserB'snodebyanotherconnectionfromUserA'snodetoUserC'snode.Serveduser:serveduseristheuserofaparticularSwMInumberwhoisrequestingthatcallstohisnumberbeforwarded.Thisusermayalsobereferredtoastheforwardinguserorthecalleduser.Tele-service:typeoftelecommunicationsservicethatprovidesthecompletecapability,includingterminalequipmentfunctions,forcommunicationbetweenusersaccordingtoagreedprotocols.Serveduser:userforwhomthesupplementaryserviceisinvoked.User:entityusingtheservicesofatelecommunicationsnetworkviaanexternallyaccessibleserviceaccesspoint.Unlessotherwisenoted,theworduseristobeunderstoodasindividualorgroup.NOTE1:Ausermaybeapersonoranapplicationprocess.Userapplication:applicationprocesswhichactsasauser(seedefinitionofuserjustabove).UserA:userAisthecallinguserofacallwhichissubjecttocallforwarding.UserB:userBistheserved(forwarding)userofacallwhichissubjecttocallforwarding.UserB1,userB2,userB3,etc.:thesearetheserved(forwarding)usersofacallwhicharesubjecttomultiplestagesofforwarding.B1isthefirstserveduser,B2isthesecondserveduser,B3isthethirdserveduser,etc.NOTE2:B2isalsotheforwarded-touserwithrespecttothefirststageofcallforwarding,B3isalsotheforwarded-touserwithrespecttothesecondstageofcallforwarding,etc.UserC:userCistheforwarded-touserwithrespecttothefinalstageofcallforwarding.SIST ETS 300 392-10-4 E2:2003



Page12ETS300392-10-4:February20003.2SymbolsForthepurposesofthisETS,therearenoadditionalsymbolsexceptedthesymbolsusedintheSDLrepresentation(ITU-TRecommendationZ.100[3]).3.3AbbreviationsForthepurposesofthisETS,thefollowingabbreviationsapply:ANFAdditionalNetworkFeatureCDCallDeflectionFCForwardingCounterGTSIGroupTETRASubscriberIdentityISDNIntegratedServicesDigitalNetworkISIInterSystemInterfaceITSIIndividualTETRASubscriberIdentityLSLineStationMSMobileStationSDLSpecificationandDescriptionLanguageSDSShortDataServiceSSSupplementaryServiceNOTE:TheabbreviationSSisonlyusedwhenreferringtoaspecificsupplementaryservice.SwMISwitchingandManagementInfrastructureTETerminalEquipmentTETRATerrestrialEuropeanTrunkedRadioV+DVoicePlusData3.3.1SupplementaryserviceabbreviationsBICBarringofIncomingCallsBOCBarringofOutgoingCallsCADCallAuthorizedbyDispatcherCCBSCallCompletiontoBusySubscriber(TETRA)CCNRCallCompletiononNoReply(TETRA)CFCallForwardingCFBCallForwardingonBusyCFNRCallForwardingonNoReply(genericforbothCFNRyandCFNRc)CFNRcCallForwardingonNotReachableCFNRyCallForwardingonNoReplyCFUCallForwardingUnconditionalCLIPCallingLineIdentificationPresentationCLIRCalling/ConnectedLineIdentificationRestrictionCOLPCOnnectedLineIdentificationPresentationCOLRCOnnectedLineIdentificationRestrictionCRCallReportCWCallWaitingDLDiscreetListeningICIncludeCallPPCPre-emptivePriorityCallSNAShortNumberAddressing4SS-CFGenericSpecificationThisgenericspecificationregroupsallelementscommontothefourCallForwardingprocedures(CFU,CFB,CFNRyandCFNRc).Eachcallforwardingprocedurehasthenitsowndedicatedpart.SS-CFUforSDSisdescribedinanotherspecificpart.FCshallbeinvokedinconjunctionwithacallforwardingrequestwhenitisdesiredtolimitthenumberofforwardingthatthecallcanencounter.Themaximumnumberofforwardingthatthecallcanencounterisnetworkdependent,intherange1to31.SIST ETS 300 392-10-4 E2:2003



Page13ETS300392-10-4:February20004.1Description4.1.1GeneraldescriptionSS-CFenablesaservedusertohavethenetworkredirect,toeitheranotherITSIortoanotherGTSI,callswhichareaddressedtotheserveduser'sITSI/GTSI/ExternalNumber.SS-CFmayoperateonallcallsorjustthoseassociatedwithspecifiedbasicservices.Theserveduser'sabilitytooriginatecallsisunaffectedbySS-CF.SS-CFisprovidedonaperITSI/GTSI/ExternalNumberbasis.Themaximumnumberofforwardingforasinglecallisanetworkimplementationoption.Whencountingthenumberofforwarding,alltypesofforwardingshallbeincluded.NOTE1:Notseentotheuser,themechanismoftheForwardingCounterallowstocountthenumberofforwardingofthecallresourceandofthesignalingconnection.NOTE2:ThemechanismoftheTransitCounterisseparatebutsimilartotheForwardingCountermechanism.CallforwardingofanindividualcallmaybeeithertoanITSIortoaGTSI;individualandgroupcallsmaybeforwardedtoeitheranITSIoraGTSI(i.e.theCommunicationTypeasdefinedinETS300392-2[4]subclause14.8.2maychangeduetoforwarding).Inthecaseoftheset-upofagroupcall,theinvocationofSS-CFbyanindividualmemberofthegrouphasnoeffectonthegroupcallset-upandthegroupcallshallnotbeforwardedtoanonmemberofthegroup.NOTE3:Asaresultofcallforwarding,theoriginalTETRAcallmaybeforwardedtoanexternalnumber.4.1.2ApplicabilitySS-CFisapplicabletoallbasicTETRAV+Dcircuitmodeservicesasdefinedinsubclause11.3.4ofETS300392-2[4](speechanddata).FCisapplicabletoallbasicservicesdefinedinETS300392-2[4].4.2Procedures4.2.1Provision/WithdrawalProvisionandwithdrawalofSS-CFshallbebypre-arrangementwiththeserviceprovider.SS-CFsubscriptionshallbeonaperITSI/GTSI/ExternalNumberbasis.ForeachITSI/GTSI/ExternalNumber,thesupplementaryservicemaybesubscribedtocollectivelyforallbasicservicessubscribedtoatthatITSI/GTSI/ExternalNumberorforonlysomeofthebasicservicessubscribedtoatthatITSI/GTSI/ExternalNumber.Thesubscriptionoptionsandvalueso
...