SIP/2.0 500 Server Internal Error
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=17eaa18-5112ed2c-13c4-50029-276ca0-5caa7810-276ca0
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.254.216.181;rport=26810;branch=foo
Supported: replaces,100rel,timer
Allow: INVITE, ACK, BYE, REFER, NOTIFY, CANCEL, OPTIONS, INFO, UPDATE, PRACK
User-Agent: Technicolor TG789vn v3 Build 10.5.2.Z.EC
X-Serialnumber: CP1403UAN6G
Accept: application/dtmf-relay, x-application/dtmf-relay, application/sdp
Content-Length: 0