SIP系统的组成 SIP协议是会话发起协议,是一个应用层协议。 SIP建立和终止多媒体通信的5个方面: ——用户位置:确定用于通信的终端系统 ——用户可用性:确定被呼叫者参加通信的意愿 ——用户能力:确定使用的媒体和媒体参数 ——会话建立:“响铃”方式建立会话 ——会话管理:包括传输和终止会话、修改会话参数以及调用服务 SIP同时和其他协议一起使用形成多媒体架构: ——RTP:实时传输协议 ——RTSP:实时传输流协议 ——SDP:会话描述协议 SIP会话流程: 其中,在2个会话主体之间,间隔着两个SIP代理,代理服务器是用来代理多个SIP终端的服务器,进行客户端信令的重定向转发。 REGISTER 注册请求不建立对话,是对SIP代理服务器(或注册服务器)进行注册本地的URI地址绑定。 该请求的答复为200OK信令。 Request-Line: REGISTER sip:172.16.80.80 SIP/2.0 Method: REGISTER Request-URI: sip:172.16.80.80 Request-URI Host Part: 172.16.80.80 [Resent Packet: False] Message Header From:<sip:25@172.16.178.25>;tag=11c587c0-0-13c4-525d6966-566380ee-525d6966 To: <sip:25@172.16.178.25> Call-ID: 11c673a0-0-13c4-525d6966-3fa1b031-525d6966 CSeq: 1 REGISTER Via: SIP/2.0/UDP172.16.178.25:5060;branch=z9hG4bK-525d6966-bce3b6f1-180cfdf User-Agent: 7920 2010 3 26 0.1 Max-Forwards: 70 Contact: <sip:172.16.178.25> Expires: 300 Content-Length: 0 200 OK(REGISTER) Status-Line: SIP/2.0 200 OK Status-Code: 200 [Resent Packet: False] [Request Frame: 48] [Response Time (ms): 26] Message Header From:<sip:25@172.16.178.25>;tag=11c587c0-0-13c4-525d6966-566380ee-525d6966 To: <sip:25@172.16.178.25>;tag=2360c00-0-13c4-62b9-52fe56a4-62b9 Call-ID: 11c673a0-0-13c4-525d6966-3fa1b031-525d6966 CSeq: 1 REGISTER Contact:<sip:172.16.178.25:5060;transport=UDP>;expires=30 Via: SIP/2.0/UDP172.16.178.25:5060;branch=z9hG4bK-525d6966-bce3b6f1-180cfdf Content-Length: 0 INVITE Request-Line: INVITE sip:17826@172.16.178.3:5060 SIP/2.0 Method: INVITE Request-URI: sip:17826@172.16.178.26:5060;transport=UDP Request-URI User Part: 17826 Request-URI Host Part: 172.16.178.26 Request-URI Host Port: 5060 [Resent Packet: False] Message Header From:<sip:17824@172.16.178.24:5060>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 To: <sip:17826@172.16.178.3:5060> CSeq: 1 INVITE Via: SIP/2.0/UDP172.16.178.24:5060;branch=z9hG4bK-521dff22-c52c9d49-700a1e12 Allow: INVITE,BYE,CANCEL,ACK,INFO,REGISTER,OPTIONS User-Agent: 7920 2010 3 26 0.1 Max-Forwards: 70 Contact: <sip:17824@172.16.178.24:5060> Content-Type: application/SDP Content-Length: 792 Message Body Session Description Protocol Version (v): 0 Owner/Creator, Session Id (o): 7920 1377697570 1 IN IP4172.16.178.24 Session Information (i): 7920 2010 3 26 0.1 Connection Information (c): IN IP4 172.16.178.24 Bandwidth Information (b): AS:2048 Time Description, active time (t): 0 0 Media Description, name and address (m): audio 60040 RTP/AVP96 0 98 9 15 8 18 102 103 99 Media Attribute (a): rtpmap:96 mp3/8000 Media Attribute (a): rtpmap:0 PCMU/8000 Media Attribute (a): rtpmap:98 G7221.C/8000 Media Attribute (a): rtpmap:9 g722-64k/8000 Media Attribute (a): rtpmap:15 G728/8000 Media Attribute (a): rtpmap:8 PCMA/8000 Media Attribute (a): rtpmap:18 G729/8000 Media Attribute (a): rtpmap:102 MP4A-LATM/8000 Media Attribute (a): rtpmap:103 MP4A-LATM/8000 Media Attribute (a): rtpmap:99 G719/8000 Media Attribute (a): fmtp:98 bitrate=24000 Media Attribute (a): fmtp:102 object=2 Media Attribute (a): fmtp:103 object=23 Media Attribute (a): rtcp:60049 Media Attribute (a): sendrecv Media Description, name and address (m): video 60042 RTP/AVP106 97 34 Bandwidth Information (b): AS:2048 Media Attribute (a): rtpmap:106 H264/90000 Media Attribute (a): rtpmap:97 MPEG4/90000 Media Attribute (a): rtpmap:34 H263/90000 Media Attribute (a): fmtp:106 profile-level-id=40804e;max-mbps=243000; max-fs=8192; Media Attribute (a): fmtp:97AUTO=1;CIF16=1;CIF4=1;CIF2=1;CIF=1; Media Attribute (a): fmtp:0 CIF=1; Media Attribute (a): rtcp:60051 Media Attribute (a): sendrecv 100 Trying Status-Line: SIP/2.0 100 Trying Status-Code: 100 [Resent Packet: False] [Request Frame: 927] [Response Time (ms): 34] Message Header From: <sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 To: <sip:17826@172.16.178.26:5060> Call-ID:11c31dd8-0-13c4-521dff22-7ac7134-521dff22@172.16.178.24 CSeq: 2 INVITE Via: SIP/2.0/UDP 172.16.178.24:5060;branch=z9hG4bK-521dff22-c52c9db3-67c76d03 Contact: <sip:17826@172.16.178.26:5060;transport=UDP> Content-Length: 0 180 Ringing Status-Line: SIP/2.0 180 Ringing Status-Code: 180 [Resent Packet: False] [Request Frame: 927] [Response Time (ms): 34] Message Header From:<sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 To:<sip:17826@172.16.178.26:5060>;tag=3143fe8-0-13c4-521dff2a-6f440c17-521dff2a CSeq: 2 INVITE Via: SIP/2.0/UDP172.16.178.24:5060;branch=z9hG4bK-521dff22-c52c9db3-67c76d03 Contact: <sip:17826@172.16.178.26:5060;transport=UDP> Content-Length: 0 200 OK Status-Line: SIP/2.0 200 OK Status-Code: 200 [Resent Packet: False] [Request Frame: 927] [Response Time (ms): 55] Message Header From:<sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 To:<sip:17826@172.16.178.26:5060>;tag=3143fe8-0-13c4-521dff2a-6f440c17-521dff2a Call-ID:11c31dd8-0-13c4-521dff22-7ac7134-521dff22@172.16.178.24 CSeq: 2 INVITE Allow: INVITE,BYE,CANCEL,ACK,INFO,REGISTER,OPTIONS,UPDATE Supported: 100rel User-Agent: UNKNOWN Level: Level_County ScreenNum: 0 Via: SIP/2.0/UDP 172.16.178.24:5060;branch=z9hG4bK-521dff22-c52c9db3-67c76d03 Contact: <sip:17826@172.16.178.26:5060;transport=UDP> Content-Type: application/SDP Content-Length: 798 Message Body Session Description Protocol Version (v): 0 Owner/Creator, Session Id (o): 7920B 1377697570 1 IN IP4172.16.178.26 Session Information (i): 7920B V1.4 Connection Information (c): IN IP4 172.16.178.26 Bandwidth Information (b): AS:12590 Time Description, active time (t): 0 0 Media Description, name and address (m): audio 60040 RTP/AVP8 0 98 9 15 96 18 99 Connection Information (c): IN IP4 172.16.178.26 Media Attribute (a): fmtp:98 bitrate=24000 Media Attribute (a): rtcp:60049 Media Attribute (a): tpattrib:capsign:0 capscreen:-1 Media Attribute (a): rtpmap:8 PCMA/8000 Media Attribute (a): rtpmap:0 PCMU/8000 Media Attribute (a): rtpmap:98 G7221.C/8000 Media Attribute (a): rtpmap:9 g722-64k/8000 Media Attribute (a): rtpmap:15 G728/8000 Media Attribute (a): rtpmap:96 mp3/8000 Media Attribute (a): rtpmap:18 G729/8000 Media Attribute (a): rtpmap:99 G719/8000 Media Attribute (a): sendrecv Media Description, name and address (m): video 60042 RTP/AVP106 97 34 Connection Information (c): IN IP4 172.16.178.26 Bandwidth Information (b): AS:8192 Media Attribute (a): fmtp:106 profile-level-id=42801f;max-mbps=216000; max-fs=3840; Media Attribute (a): fmtp:97AUTO=1;CIF16=1;CIF4=1;CIF2=1;CIF=1; Media Attribute (a): fmtp:34 CIF=1; Media Attribute (a): rtcp:60051 Media Attribute (a): tpattrib:capsign:0 capscreen:-1 Media Attribute (a): rtpmap:106 H264/90000 Media Attribute (a): rtpmap:97 MPEG4/90000 Media Attribute (a): rtpmap:34 H263/90000 Media Attribute (a): sendrecv ACK Request-Line: ACK sip:17826@172.16.178.26:5060;transport=UDPSIP/2.0 Method: ACK Request-URI: sip:17826@172.16.178.26:5060;transport=UDP [Resent Packet: False] [Request Frame: 927] [Response Time (ms): 159] Message Header From: <sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 To:<sip:17826@172.16.178.26:5060;transport=UDP>;tag=3143fe8-0-13c4-521dff2a-6f440c17-521dff2a Call-ID:11c31dd8-0-13c4-521dff22-7ac7134-521dff22@172.16.178.24 CSeq: 2 ACK Via: SIP/2.0/UDP172.16.178.24:5060;branch=z9hG4bK-521dff22-c52c9e56-4838bad0 Max-Forwards: 70 Contact: <sip:17824@172.16.178.24:5060;transport=UDP> Content-Length: 0 INFO Request-Line: INFOsip:17824@172.16.178.24:5060;transport=UDP SIP/2.0 Method: INFO Request-URI: sip:17824@172.16.178.24:5060;transport=UDP [Resent Packet: False] Message Header From: <sip:17826@172.16.178.26:5060>;tag=3143fe8-0-13c4-521dff2a-6f440c17-521dff2a To:<sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 Call-ID:11c31dd8-0-13c4-521dff22-7ac7134-521dff22@172.16.178.24 CSeq: 1 INFO Via: SIP/2.0/UDP172.16.178.26:5060;branch=z9hG4bK-521dff2a-c52cbeae-5f3840e7 Max-Forwards: 70 Contact: <sip:17826@172.16.178.26:5060;transport=UDP> Content-Type: application/media_control+xml Content-Length: 198 Message Body eXtensible Markup Language 200 OK(INFO) Status-Line: SIP/2.0 200 OK Status-Code: 200 [Resent Packet: False] Message Header From: <sip:17826@172.16.178.26:5060;transport=UDP>;tag=3143fe8-0-13c4-521dff2a-6f440c17-521dff2a To:<sip:17824@172.16.178.24:5060;transport=UDP>;tag=11c2d510-0-13c4-521dff22-6a332c0d-521dff22 Call-ID:11c31dd8-0-13c4-521dff22-7ac7134-521dff22@172.16.178.24 CSeq: 1 INFO Via: SIP/2.0/UDP172.16.178.26:5060;branch=z9hG4bK-521dff2a-c52cbeae-5f3840e7 Contact: <sip:17824@172.16.178.24:5060;transport=UDP> Content-Length: 0 ———————————————— 版权声明:本文为CSDN博主「红坦坦」的原创文章,遵循CC4.0 BY-SA版权协议,转载请附上原文出处链接及本声明。 原文链接:https://blog.csdn.net/davidsguo008/article/details/73353837
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