REGISTER sip:company.com SIP/2.0
Via: SIP/2.0/UDP rama.research.nokia.com
Via: SIP/2.0/UDP 135.180.130.133
To: sip:j.user@COMPANY.COM;maddr=135.180.130.133;tag=foo
From: sip:j.user@COMPANY.COM;tag=bar
Call-ID: 0ha0isndaksdj@10.0.2.2  
Contact: *
CSeq: 9 REGISTER
Content-Length: 0
