SIP/2.0 200 OK
Via: SIP/2.0/UDP nm;branch=foo;received=224.167.252.72;rport=26810
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=as01561c0a
Call-ID: 50000
CSeq: 42 OPTIONS
Server: FPBX-15.0.37.4(13.38.3)
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
Supported: replaces, timer
Contact: <sip:46.232.239.58:1164>
Accept: application/sdp
Content-Length: 0