OPTIONS sip:nobody@10.1.1.13:5060 SIP/2.0
Via: SIP/2.0/TCP 10.252.0.17:44241;branch=z9hG4bK.0010ce2c;rport;alias
From: sip:sipsak@10.252.0.17:44241;tag=3c7a11cf
To: sip:nobody@10.1.1.13:5060
Call-ID: 1159657@10.252.0.17
CSeq: 159657 OPTIONS
Contact: sip:sipsak@10.252.0.17:44241
Content-Length: 0
Max-Forwards: 70
User-Agent: sipsak 0.9.6
Accept: text/plain