SIP 逄愛君
SIP&SDP2 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Outline SIP Overview SIP Components SIP Messages SIP Services SDP Conclusion
SIP&SDP3 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Overview Session Initiation Protocol The signaling protocol for creating, modifying and terminating sessions Session=audio, video… IETF Proposed Standard (RFC 2543) February 2, 1999 Currently under development within the Multiparty Multimedia Session Control (MMUSIC) working group
SIP&SDP4 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Overview 15 Companies test interoperability between their equipment April 1999 3Com, Alcatel, Cisco, British, British Telecom, Columbia University, Dialogic, Ericsson, HP, Lucent, MCI, Nortel,…
SIP Architecture
SIP&SDP6 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP’s Role to SS7 Signaling Gateway Signaling Gateway Media Gateway Controller Media Gateway Controller MGC SG SIP Proxy SIP Proxy RTP Megaco IP Network to PSTN SIP sigtran Media Gateway Media Gateway Media Gateway Media Gateway SIP Client SIP Client sigtran Megaco to PSTN to SS7
SIP&SDP7 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Overview Client-Server Model Flexibility & Extensibility Text-based Encoding Transport Independence UDP or TCP Security Secure Sockets Layer (SSL) for TCP-based SIP
SIP&SDP8 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Components User Agents Client (UAC) To initiate a SIP request Server (UAS) To receive the request and return responses Servers Proxy Redirect Registrar
SIP&SDP9 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Addressing & Naming The entities addressed by SIP are users at hosts -like identifier of the form Examples
SIP&SDP10 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Messages Two kinds of SIP messages Request and Response Request message format Request Line Method, Request URI, Version General, Request, Entity Headers An Empty Line (CRLF) Indicating the end of the header fields Message Body Session Description Protocol (SDP) : Optional
SIP&SDP11 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Messages (cont’d) Response message format Start-line Status-Line General, Response, Entity Headers An Empty Line (CRLF) Indicating the end of the header fields Message Body Session Description Protocol (SDP) : Optional
SIP&SDP12 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Methods INVITE The user is being invited to participate in a session. ACK The request confirms that the client has received a final response to an INVITE request. BYE The client wishes to release the call.
SIP&SDP13 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Methods (cont’d) OPTIONS It queries the features the other side supports. CANCEL It cancels a pending request (not completed request). REGISTER It conveys the user’s location information to a SIP server.
SIP&SDP14 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Header Fields General Apply to both request and response messages Entity Define information about the message body Request Allow the user agent client to pass additional information about the request Response Allow the user agent server to pass additional information about the response
SIP&SDP15 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Headers
SIP&SDP16 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Request Example INVITE SIP/2.0 Via: SIP/2.0/UDP science.fiction.com From: Fingal To: Patric Call-ID: Cseq: 1 INVITE Subject: lunch at La Empenada? Content-Type: applcation/sdp Content-Length: …
SIP&SDP17 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Response
SIP&SDP18 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Response (cont’d)
SIP&SDP19 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Response Example SIP/ OK Via: SIP/2.0/UDP sippo.example.se Via: SIP/2.0/UDP science.fiction.com From: Fingal To: Patric Call-ID: Cseq: 1 INVITE Content-Type: applcation/sdp Content-Length: …
SIP&SDP20 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Invitation for SIP Proxy
SIP&SDP21 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Invitation for Redirect Server
SIP&SDP22 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP+ISDN (Q.931)
SIP+MGCP
SIP / MGCP / ISUP
SIP&SDP25 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang SIP Services Similar to the Intelligent Network (IN) services Call Transfer, Call Forwarding, Conference Calling, User Mobility…
SIP Mobility
SIP&SDP27 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Conclusion SIP is a light-weight signaling protocol. The amount of companies backing SIP is crucial for survival. MCI (the biggest backer), 3Com, Lucent and DynamicSoft… The low complexity level of the SIP, compared to H.323 (H.245 & H.225), should make companies interested. 3G Wireless Technology 3GPP-> H.323 3GIP->SIP
SIP&SDP28 Industrial Technology Research Institute Computer & Communication Research Laboratories Elgin Pang Discussion