SIP/2.0 404 Not Found
Via: SIP/2.0/UDP nm;branch=foo;received=255.255.255.255;rport=0
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=1066543622
Call-ID: 50000
CSeq: 42 OPTIONS
Content-Length: 0