SIP/2.0 200 OK
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=9405d4f0-0-13c4-86c5-6c207ccc-86c5
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.36.163.189;rport=26810;branch=foo
Supported: 100rel,replaces,timer,path
Contact: <sip:127.0.0.1:5060>
Content-Length: 0
