SIP/2.0 200 OK
Via: SIP/2.0/UDP nm;branch=foo;rport=26810;received=224.92.194.224
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=1698067403
Call-ID: 50000
CSeq: 42 OPTIONS
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, SUBSCRIBE, NOTIFY, INFO
Accept: application/sdp
User-Agent: Linphone/3.5.2 (eXosip2/3.6.0)
Content-Length: 0