OPTIONS sip:user@example.com SIP/2.0
To: sip:user@example.com
From: caller<sip:caller@example.com>;tag=323
Max-Forwards: 70
Call-ID: lwsdisp.1234abcd@funky.example.com
CSeq: 60 OPTIONS
Via: SIP/2.0/UDP funky.example.com;branch=z9hG4bKkdjuw
l: 0
