SIP/2.0 500 Server Internal Error
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=18e24c0-ee5b3a31-62a85578-37918c74-a67bd5b4-541AB0
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.129.170.12;rport=26810;branch=foo
Supported: replaces,100rel,timer
Allow: INVITE, ACK, BYE, REFER, NOTIFY, CANCEL, OPTIONS, INFO, UPDATE, PRACK
User-Agent: MediaAccess TG789vac Build 10.5.8.E.BS CP1709UA8YY
X-Serialnumber: CP1709UA8YY
Accept: application/dtmf-relay, x-application/dtmf-relay, application/sdp
Content-Length: 0