SIP/2.0 200 OK
Via: SIP/2.0/UDP nm;rport=26810;received=224.42.175.248;branch=foo
Call-ID: 50000
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=foo
CSeq: 42 OPTIONS
Allow: INVITE, ACK, BYE, CANCEL, UPDATE, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE, OPTIONS, PRACK
Accept: application/sdp, message/sipfrag;version=2.0, application/sdp
Supported: replaces, timer
Allow-Events: refer
User-Agent: AVCON-SIP2.0
Content-Length: 0