2010/6/22 Xiaoqiang Hu xhu@redhat.com:
0009: <UA11 REGISTER sip:ss.under.test.com:5060 SIP/2.0 Via: SIP/2.0/UDP node.under.test.com:5060;branch=z9hG4bKPUA9595277 Max-Forwards: 70 Authorization: Digest username="UA11", realm="under.test.com", qop=auth, nonce="4c147d11e24598379c733aa74854fa99f9880361", opaque="", nc=00000001, cnonce="6f54a149", uri="sip:ss.under.test.com:5060", response="d07dd11c48b2385d8f0f147682ead94f" From: UA11 sip:UA11@under.test.com;tag=11174 To: UA11 sip:UA11@under.test.com Call-ID: 11174@lan.example.com CSeq: 3 REGISTER Contact: sip:UA11@node.under.test.com;transport=udp Contact: sip:11UA11@node.under.test.com;transport=udp Expires: 3600 Content-Length: 0
0010: >UA11 SIP/2.0 200 OK Via: SIP/2.0/UDP node.under.test.com:5060;branch=z9hG4bKPUA9595277;received=3FFE:501:FFFF:1:0:0:0:1 From: UA11 sip:UA11@under.test.com;tag=11174 To: UA11 sip:UA11@under.test.com;tag=0c0d2af89845c72ddfdc7de2133116df.6168 Call-ID: 11174@lan.example.com CSeq: 3 REGISTER Date: Sun, 13 Jun 2010 06:34:13 GMT Contact: sip:UA11@node.under.test.com;transport=udp;expires=3600, sip:11UA11@node.under.test.com;transport=udp;expires=3600 Server: OpenSER (1.3.4-tls (i386/linux)) Content-Length: 0
This is 100% valid according to RFC 3261. A REGISTER can contain various bindings to being registered.