SIP/2.0 200 OK
Via: SIP/2.0/UDP kton.bell-tel.com
From: A. Bell <sip:a.g.bell@bell-tel.com>;tag=3
To: <sip:watson@bell-tel.com> ;tag=37462311
Call-ID: 662606876@kton.bell-tel.com
CSeq: 1 INVITE
Contact: sip:watson@boston.bell-tel.com
Content-Type: application/sdp
Content-Length: 130

v=0
o=watson 4858949 4858949 IN IP4 192.1.2.3
s=I'm on my way
t=3149329600 0
c=IN IP4 boston.bell-tel.com
m=audio 5004 RTP/AVP 0 3
a=rtpmap:0 PCMU/8000
a=rtpmap:3 GSM/8000