ITU-T J.218 (07 2007) (英) Cable modem IPv4 and IPv

InternationalTelecommunicationUnionITU-TJ.218TELECOMMUNICATIONSTANDARDIZATIONSECTOROFITU(07/2007)SERIESJ:CABLENETWORKSANDTRANSMISSIONOFTELEVISION,SOUNDPROGRAMMEANDOTHERMULTIMEDIASIGNALSInteractivesystemsfordigitaltelevisiondistributionCablemodemIPv4andIPv6eRouterspecificationITU-TRecommendationJ.218ITU-TRec.J.218(07/2007)iITU-TRecommendationJ.218CablemodemIPv4andIPv6eRouterspecificationSummaryITU-TRecommendationJ.218definesacoresetoffeaturesthatenablesmultiplesubscriberdevicestogainaccesstooperator-providedhighspeeddataserviceusingDOCSIS.ThiscoresetoffeaturesallowsforbothIPv4andIPv6enableddevicestogainconnectivitytotheInternet.TheeRouterisspecifiedasanembeddedservice/applicationfunctionalentity(eSAFE)deviceasdefinedinITU-TRecommendationJ.126thatisimplementedinconjunctionwithaDOCSIScablemodemdevice.ThecoresetoffeaturesdefinedinthisRecommendationincludestheabilitytoprovisionmultipleCPEdevices,adescriptionofhowtoforwarddatatoandfromCPEdevicesandalsotheabilitytoforwardIPmulticasttraffictoCPEdevices.SourceITU-TRecommendationJ.218wasapprovedon29July2007byITU-TStudyGroup9(2005-2008)undertheITU-TRecommendationA.8procedure.iiITU-TRec.J.218(07/2007)FOREWORDTheInternationalTelecommunicationUnion(ITU)istheUnitedNationsspecializedagencyinthefieldoftelecommunications,informationandcommunicationtechnologies(ICTs).TheITUTelecommunicationStandardizationSector(ITU-T)isapermanentorganofITU.ITU-Tisresponsibleforstudyingtechnical,operatingandtariffquestionsandissuingRecommendationsonthemwithaviewtostandardizingtelecommunicationsonaworldwidebasis.TheWorldTelecommunicationStandardizationAssembly(WTSA),whichmeetseveryfouryears,establishesthetopicsforstudybytheITU-Tstudygroupswhich,inturn,produceRecommendationsonthesetopics.TheapprovalofITU-TRecommendationsiscoveredbytheprocedurelaiddowninWTSAResolution1.InsomeareasofinformationtechnologywhichfallwithinITU-T'spurview,thenecessarystandardsarepreparedonacollaborativebasiswithISOandIEC.NOTEInthisRecommendation,theexpressionAdministrationisusedforconcisenesstoindicatebothatelecommunicationadministrationandarecognizedoperatingagency.CompliancewiththisRecommendationisvoluntary.However,theRecommendationmaycontaincertainmandatoryprovisions(toensuree.g.interoperabilityorapplicability)andcompliancewiththeRecommendationisachievedwhenallofthesemandatoryprovisionsaremet.Thewordsshallorsomeotherobligatorylanguagesuchasmustandthenegativeequivalentsareusedtoexpressrequirements.TheuseofsuchwordsdoesnotsuggestthatcompliancewiththeRecommendationisrequiredofanyparty.INTELLECTUALPROPERTYRIGHTSITUdrawsattentiontothepossibilitythatthepracticeorimplementationofthisRecommendationmayinvolvetheuseofaclaimedIntellectualPropertyRight.ITUtakesnopositionconcerningtheevidence,validityorapplicabilityofclaimedIntellectualPropertyRights,whetherassertedbyITUmembersorothersoutsideoftheRecommendationdevelopmentprocess.AsofthedateofapprovalofthisRecommendation,ITUhadnotreceivednoticeofintellectualproperty,protectedbypatents,whichmayberequiredtoimplementthisRecommendation.However,implementersarecautionedthatthismaynotrepresentthelatestinformationandarethereforestronglyurgedtoconsulttheTSBpatentdatabaseat©ITU2008Allrightsreserved.Nopartofthispublicationmaybereproduced,byanymeanswhatsoever,withoutthepriorwrittenpermissionofITU.ITU-TRec.J.218(07/2007)iiiCONTENTSPage1Scope............................................................................................................................12References.....................................................................................................................12.1Normativereferences......................................................................................12.2Informativereferences....................................................................................32.3Referenceacquisition.....................................................................................33Termsanddefinitions...................................................................................................34Abbreviations,acronymsandconventions...................................................................34.1Abbreviationsandacronyms..........................................................................34.2Conventions....................................................................................................55Theoryofoperation......................................................................................................56eRouterinitialization....................................................................................................77IPv4provisioning.........................................................................................................87.1DHCPv4fieldsusedbytheeRouter...............................................................97.2RouterDHCPv4serversub-element..............................................................108IPv6provisioning.........................................................