REGISTER sip:proxy.bhr.vivox.com:5062 SIP/2.0 Via: SIP/2.0/UDP 202.26.159.137:22891;rport;branch=z9hG4bK831225887 From: ;tag=561498858 To: Call-ID: 1962420700@202.26.159.137 CSeq: 1 REGISTER Contact: Max-Forwards: 70 User-Agent: Vivox-SDK-2.0.2961.3323-Win/Feb--4-2008/16:23:20 Expires: 1200 Content-Length: 0