SIP/2.0 200 OK
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=9d8610-0-13c4-1d4707-5c6dbab4-1d4707
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.126.163.120;rport=26810;branch=foo
Supported: 100rel,replaces,timer,path
Contact: <sip:127.0.0.1:5060>
Content-Length: 0
