REGISTER sip:[2001:db8::10:5070] SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Contact: "Caller" <sip:caller@[2001:db8::1]>
Max-Forwards: 70
CSeq: 98176 REGISTER
Content-Length: 0

