SIP/2.0 200 OK
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=9c0682b8-0-13c4-817a72-7acf4372-817a72
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.91.221.214;rport=26810;branch=foo
Supported: 100rel,replaces,timer,path
Contact: <sip:127.0.0.1:5060>
Content-Length: 0
