SIP/2.0 200 OK
Via: SIP/2.0/UDP nm;rport=26810;received=224.97.44.78;branch=foo
Call-ID: 50000
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=foo
CSeq: 42 OPTIONS
Accept: application/sdp, application/dialog-info+xml, application/simple-message-summary, application/simple-message-summary, application/pidf+xml, application/dialog-info+xml, application/pidf+xml, application/xpidf+xml, application/cpim-pidf+xml, message/sipfrag;version=2.0
Allow: OPTIONS, NOTIFY, SUBSCRIBE, NOTIFY, PUBLISH, INVITE, ACK, BYE, CANCEL, UPDATE, PRACK, REFER, MESSAGE, REGISTER
Supported: 100rel, timer, replaces, norefersub
Accept-Encoding: text/plain
Accept-Language: en
Server: Yeastar S20-30.14.0.23
Content-Length: 0
