SIP/2.0 500 Server Internal Error
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=1aae540-d4548a56-13c4-50029-17de573-15d1ddfd-17de573
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.186.40.32;rport=26810;branch=foo
Supported: replaces,100rel
Allow: INVITE, ACK, BYE, REFER, NOTIFY, CANCEL, OPTIONS, INFO, UPDATE, PRACK
User-Agent: Technicolor TG789vn v3 Build 10.5.2.Y.DW
X-Serialnumber: CP1304RARM1
Accept: application/dtmf-relay, x-application/dtmf-relay, application/sdp
Content-Length: 0