INVITE sip:foo@127.0.0.1:5061  SIP/2.0
Via: SIP/2.0/UDP 127.0.0.1
Via: SIP/2.0/UDP 127.0.0.1:5061
From:  <sip:x@foo.bar>
To: <sip:y@bar.foo>
Call-ID: 9437892232b@foo.bar
CSeq: 143 INVITE
Contact:<sip:x@foo.bar>