REGISTER sip:example.com SIP/2.0 To: sip:j.user@example.com From: sip:j.user@example.com;tag=43251j3j324 Max-Forwards: 8 I: dblreq.0ha0isndaksdj99sdfafnl3lk233412 Contact: sip:j.user@host.example.com CSeq: 8 REGISTER Via: SIP/2.0/UDP 192.0.2.125;branch=z9hG4bKkdjuw23492 Content-Length: 0 INVITE sip:joe@example.com SIP/2.0 t: sip:joe@example.com From: sip:caller@example.net;tag=141334 Max-Forwards: 8 Call-ID: dblreq.0ha0isnda977644900765@192.0.2.15 CSeq: 8 INVITE Via: SIP/2.0/UDP 192.0.2.15;branch=z9hG4bKkdjuw380234 Content-Type: application/sdp Content-Length: 150 v=0 o=mhandley 29739 7272939 IN IP4 192.0.2.15 s=- c=IN IP4 192.0.2.15 t=0 0 m=audio 49217 RTP/AVP 0 12 m =video 3227 RTP/AVP 31 a=rtpmap:31 LPC