SIP协议深入介绍

SIP1SIP1SIPSIPSessionInitiationProtocolUserlocationUseravailabilityUsercapabilitiesSessionsetupSessionmanagementSIPIETFRTP(RealTimeTransport)QoSRTSP(RealTimeStreamingprotocol)MEGACO(MediaGatewayControlProtocol)SDPSessionDescriptionProtocol11SIPSIP12SIP3SIPprovisionalresponse(finalresponse)INVITE2xxACK2xxACKINVITEUAstatefulproxystatelessproxy(clienttransaction)servertransactionUA(statefulSIP2proxyserver)statelessproxyTUUAstatefulproxyACKINVITE2xxfinalresponse3xx-6xxACKTUTUINVITE2xxfinalresponse3xx-6xxACK2xxACK2xxUAS2xxACKUAC2xx2xxACKUAScoreUACcoreUACUASProxy2xxACK2xxTUTUTUProxycoreUACCoreUACCoreINVITEACK(non-INVITEACK)ProxyForward4SIPUACUASstatefulproxystatelessproxyregistrarcorestatelessproxySIPcoreTU12SIPSIPstartline;headfields;emptylinemessage-bodygeneric-message=start-line*message-headerCRLF[message-body]start-line=Request-Line/Status-LineRequestRequest-Line=MethodSPRequest-URISPSIP-VersionCRLFMethodREGISTERINVITE,ACK,CANCELBYEOPTIONSRequest-URI:SIPSIPSURItelURIrequesttofieldURIregisterlocationservice,SIP-VersionrequestresponseSIPSIP3ResponseStatus-Line=SIP-VersionSPStatus-CodeSPReason-PhraseCRLFStatus-Code1xx:Provisional--requestreceived,continuingtoprocesstherequest;2xx:Success--theactionwassuccessfullyreceived,understood,andaccepted;3xx:Redirection--furtheractionneedstobetakeninordertocompletetherequest;4xx:ClientError--therequestcontainsbadsyntaxorcannotbefulfilledatthisserver;5xx:ServerError--theserverfailedtofulfillanapparentlyvalidrequest;6xx:GlobalFailure--therequestcannotbefulfilledatanyserver.headfieldsheader=header-nameHCOLONheader-value*(COMMAheader-value)(ViaToFromCSeqCall-IDMax-Forwards)Via:SIP/2.0/UDPpc33.atlanta.com;branch=z9hG4bKnashds8;received=192.0.2.1ViaheadfieldViaSIPViaSIPUACViaUACSIPViaSIPSIPSIPViareceivedSIPSIPmulti-homedhostRFC3261P180SIPUACProxyViabranchUArequestbranchCANCEL2XXresponseACKCANCELcancelrequestbranchINVITEfinalresponsenon-2xxresponseACKINVITEbranchCANCEL2XXresponseACKcancelrequestINVITERFC3261P39P122branchloopdetectionRFC3261z9hG4bKloopdetectionloopspiralloopspiralProxyProxyloopRequest-URIProxySpiralspiralRequest-URIProxyViabranchloopSIP4detectionToTagFromTagCall-IDRequest-URITopmostViaCseqrequestmethodproxy-requireproxyauthorizationrequestmethodbranchCANCEL2XXresponseACKcancelrequestINVITEbranchRFC3261P22P25P39P95P105ViaSIPMax-Forwards:70Max-ForwardsheadfieldrequestUASMax-Forwardsrequest483(toomanyhops)To:Bobsip:[e-mail]”logical”recipientREGISTERrequestrecipientToheadfieldREGISTERLocationServeraddress-of-recordvs.contactaddressToheadfieldtagtotagdialogpeerUACDialogINVITEout-of-dialogdialogtotagUASINVITE2xx101-199totagUACFromTagCall-IDDialogIDTotagFromTagCall-IDRFC3261INVITE2xx101-199Dialog101-199DialogearlydialogRFC3261P70RFC3261P36P159P178From:Alicesip:[e-mail];tag=1928301774FromheadfieldrequestlogicalREGISTERfromheadfieldREGISTERaddress-of-recordvs.contactaddressFromheadfieldToheadfieldURIdisplaynameFromheadfieldUAIPFromFromSIPFromFromtagUACout-of-dialogtagDialogIDRFC3261P37P159P172SIP5Call-ID:a84b4c76e66710Call-IDheadfield(Invitation)UAC(Registeration)DialogForkingCall-IDCall-IDUACFromTagUASToTagDialog-IDDialogrequestsresponsesCall-IDUAregisterCall-IDRFC3261P37P159P166CSeq:314159INVITECSeqheadfieldDialogtransaction-retransmissionre-REQUESTre-INVITE4xxre-REQUESTRFC3261P45CSeqmethodrequestout-of-dialogregisterrequestdialogrequestBYE,re-INVITE,OPTIONCseq1CANCEL,ACKACKCseqrequestCANCELCseqcancelrequestUACUASCSeqCSeqRFC3261P218RFC3261P38P159P170P218Contact:sip:[e-mail]terContactheaderfieldUACUASSIPURIUACout-of-dialogINVITEContactSIPURIUASContactSIPURIUASIPURIProxyRegistercontactaddressvs.address-of-recordContent-Type:application/sdpContent-typeheaderfieldContent-typeheaderfieldContent-typeheaderfield0SIP6Content-Length:142Content-lengthheaderfield(Alice'sSDPnotshown)SIPMessageBodySDP//SIPRequestline/StatuslineHeadersCRLFv=0//0o=UserA28908445262890844526INIP4here.com//IDs=SessionSDP//c=INIP4100.101.102.103//t=00//m=audio49172RTP/AVP0//49172RTPAVT0uPCMa=rtpmap:0PCMU/8000//0//rtpmap0PCMU8KHz……//SDPSIPoffer/answerUASDPa)UAofferaduio,video,gamescodextypesanswerb)UAofferUAofferc)UAoffer/answerINVITEUAoffer/answerd)SDPINVITEresponseACKSDPoffer/answeri.INVITESDPoffer2xxresponseSDPanswerii.2xxresponseSDPofferACKSDPanswerSIP72alice’sAtlanta.comBiloxi.combob’ssoftphoneproxyproxySIPphoneINVITEF1INVITEF2100TRYINGF3INVITEF4100TRYINGF5180RINGINGF6180RINGINGF7180RINGINGF8200OKF9200OKF10200OKF11ACKF12MEDIASESSIONBYEF13200OKF141.AlicePCSIPBobBobInternetSIPPhoneAliceBobSIPSIPURIsip:[e-mail]derAliceSIPURIsip:[e-mail]81)Alice’ssoftphoneBobbiloxi.comSIPAliceINVITEAliceatlanta.comSIPAlicesoftphoneDHCPAliceUACViaUACViabranchAliceUACout-of-dialogFromtagDialogIDAliceUACContactSIPURIF1INVITEAlice-atlanta.comproxyINVITEsip:[e-mail]/2.0Via:SIP/2.0/UDPpc33.atlanta.com;branch=z9hG4bKnashds8Max-Forwards:70To:Bobsip:[e-mail]:Alicesip:[e-mail]