SIP/2.0 404 Not Found
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=9e8d40-0-13c4-50029-86fb0-464842a2-86fb0
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.149.12.85;rport=26810;branch=foo
Supported: replaces,100rel,timer
Accept: application/sdp
Allow: INVITE,ACK,CANCEL,BYE,OPTIONS,REFER,INFO,NOTIFY,PRACK,MESSAGE
Content-Length: 0

HTTP/1.1 500 Internal Server Error
SERVER: Linux/2.6.21.5, UPnP/1.0, Portable SDK for UPnP devices/1.6.6
CONNECTION: close
CONTENT-LENGTH: 60
CONTENT-TYPE: text/html