INVITE name:John_Smith SIP/2.0
To: isbn:2983792873
From: http://www.cs.columbia.edu
Call-ID: 0ha0isndaksdj@10.1.2.3
CSeq: 8 INVITE
Via: SIP/2.0/UDP 135.180.130.133
Content-Type: application/sdp
Contact: Joe Bob Briggs <urn:ipaddr:122.1.2.3>

v=0
o=mhandley 29739 7272939 IN IP4 126.5.4.3
c=IN IP4 135.180.130.88
m=audio 49210 RTP/AVP 0 12
m=video 3227 RTP/AVP 31
a=rtpmap:31 LPC/8000