SIP/2.0 500 Server Internal Error
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=194d508-6911679c-f2996e81-4a63e5a6-2817a2d-A302AA
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.128.25.173;rport=26810;branch=foo
Supported: replaces,100rel
Allow: INVITE, ACK, BYE, REFER, NOTIFY, CANCEL, OPTIONS, INFO, UPDATE, PRACK
User-Agent: MediaAccess TG789vac v2 Build 10.5.8.R.FR CP1724UAPYQ
X-Serialnumber: CP1724UAPYQ
Accept: application/dtmf-relay, x-application/dtmf-relay, application/sdp
Content-Length: 0