Content-Type: application/sdp Call Flow Examples Content-Length: 126 o=Ada 2890844536 2890844536 IN IP4 1.2.3.4 t=0 0 C=IN IP4 1.2.3.4 m=audio 52310 RTP/AVP 0 a=rtpmap: 0 PCMU/8000 SIP/2.0 200 OK Via: SIP/2.0/UDP 12.26.17.91:5060;branch=z9hG4bK221 From: Charles Babbage <sip:babbage@analyticalsoc.org>;tag=9382 To: <sip:ada@language.org>;tag=65a3547e3 Call-ID: f6-32-9a-34-91-e7@analyticalsoc.org CSeq: 2 INVITE Contact: sip:ada@drawingroom.language.org Record-Route: <sip:10.14.92.1;lr> Content-Type: application/sdp Content-Length: 126 o=Ada 2890844536 2890844536 IN IP4 1.2.3.4 t=0 0 C=IN IP4 1.2.3.4 m=audio 52310 RTP/AVP 0 a=rtpmap: 0 PCMU/8000 M19 ACK sip:ada@drawingroom.language.org SIP/2.0 <Sent to ALG Via: SIP/2.0/UDP 12.26.17.91:5060;branch=z9hG4bK789 Max-Forwards: 70 From: Charles Babbage <sip:babbage@analyticalsoc.org>;tag=9382 To: <sip:ada@language.org>;tag=65a3547e3 Call-ID: f6-32-9a-34-91-e7@analyticalsoc.org CSeq: 2 ACK Route: <sip:10.14.92.1;lr> M20 ACK sip:ada@drawingroom.language.org SIP/2.0 Via: SIP/2.0/UDP 10.14.92.1:5060;branch=z9hG4bK24105.1 Via: SIP/2.0/UDP 12.26.17.91:5060;branch=z9hG4bK789 Max-Forwards: 69 From: Charles Babbage sip:babbage@analyticalsoc.org>;tag=9382 To: k<sip:ada@language.org>;tag=65a3547e3 Call-ID: 6-32-9a-34-91-e7@analyticalsoc.org CSeq: 2 INVITE M21 BYE ip:babbage@client.analyticalsoc.org SIP/2.0 Via: SIP/2.0/UDP 1.2.3.4:5060;branch=z9hG4bk541 Max-Forwards: 70 SIP: Understanding the Session Initiation Protocol From: Ada Lovelace k<sip:ada@language.org>;tag=65a3547e3 To: Charles Babbage k<sip:babbage@analyticalsoc.org>;tag=9382 Call-ID: f6-32-9a-34-91-e7@analyticalsoc.org CSeq: 1000 BYE <CSeq initialized to 1000 Route: <sip:10.14.92.1;lr> <From Record-Route header M22 BYE sip:babbage@client.analyticalsoc.org SIP/2.0 Via: SIP/2.0/UDP 10.14.92.1:5060;branch=z9hG4bK24105.1 Via: SIP/2.0/UDP .2.3.4:5060;branch=z9hG4bK543 Max-Forwards: 69 From: Ada Lovelace ksip:ada@language.org>;tag=65a3547e3 To: Charles Babbage <sip:babbage@analyticalsoc.org>;tag=9382 Call-ID: 16-32-9a-34-91-e7@a