1. Configuration Guide
  2. IMS Support
  3. Wildcard Public User Identity (PUI)
  4. Message Flows

Message Flows

A basic registration exchange with support for PUIs enabled.

From UA to P-CSCF 

REGISTER sip:192.168.1.232:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.231:5060;branch=z9hG4bK-13794-1-0
From: <sip:7818888@hxu.com;tag=1
To: sut <sip:7818888@hxu.com>
Call-ID: 1-13794@192.168.1.231
CSeq: 1 REGISTER
Contact: <sip:7818888@192.168.1.231:5060>;expires=3600
Content-Length: 0

From P-CSCF to Registrar

If reg-cache-route is enabled on egress sip-interface, P-CSCF provides Path support with a value of P-CSCF-contact, so INVITE from core will have route header with value of this path per RFC 3327. 

REGISTER sip:192.168.200.231:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.200.232:5060;branch=z9hG4bK0g6tnu200o10tfgl0641.1
From: <sip:7818888@hxu.com;tag=1
To: sut <sip:7818888@hxu.com>
Call-ID: 1-13794@192.168.1.231
CSeq: 1 REGISTER
Contact: <sip:7818888-rrbgth3ot667c@192.168.200.232:5060;transport=udp>;expires=3600
Content-Length: 0
Supported: path
Path: <sip:7818888-rrbgth3ot667c@192.168.200.232:5060; lr>
Max-Forwards: 70

From Registrar to P-CSCF 

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.200.232:5060;branch=z9hG4bK0g6tnu200o10tfgl0641.1
Call-ID: 1-13794@192.168.1.231
CSeq: 1 REGISTER
Contact: <sip:7818888-rrbgth3ot667c@192.168.200.232:5060;transport=udp>;expires=3600
P-Associated-URI: <sip:781!.*!@hxu.com>  -- wildcard regex
Content-Length: 0

From P-CSCF to UA 

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.1.231:5060;branch=z9hG4bK-13794-1-0
From: <sip:7818888@hxu.com;tag=1
To: sut <sip:7818888@hxu.com>;tag=1
Call-ID: 1-13794@192.168.1.231
CSeq: 1 REGISTER
Contact: <sip:7818888@192.168.1.231:5060>;expires=3600
P-Associated-URI: <sip:781!.*!@hxu.com>
Content-Length: 0

Incoming Request INVITE from core

For the incoming request from the core to the P-CSCF, if reg-cache-route is enabled on ingress SIP Interface, P-CSCF checks the registered P-CSCF-contact-URI in the top Route P-CSCF-contact-URI, instead of with request-URI. 

INVITE sip:7816666@192.168.200.232:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.200.231:5060;branch=z9hG4bK-13800-1-0
From: sipp <sip:3054252165@192.168.200.231:5060;user=phone>;tag=1
To: sut <sip:7816666@hxu.com>
Call-ID: 1-13800@192.168.200.231
Supported: 100rel,timer,resource-priority,replaces
CSeq: 1 INVITE
Contact: sip:7816666@192.168.200.231:5060
Max-Forwards: 70
Route: <sip:7818888-rrbgth3ot667c@192.168.200.232:5060;lr>
Content-Type: application/sdp
Content-Length:  141

v=0^M
o=user1 53655765 2353687637 IN IP4 192.168.200.231
s=-
c=IN IP4 192.168.200.231
t=0 0
m=audio 6000 RTP/AVP 0
a=rtpmap:0 PCMU/8000

outgoing Request INVITE

For outgoing Request from access side, the Register Cache entry will be found by reg-via-key, when options ‘reg-via-key’ and ‘reg-via-match’ are set, P-CSCF will have wildcarded PAU checking for allow-anonymous (or registered) verification if option wildcard-puid-match is set. 

INVITE sip:service@192.168.1.232:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.231:5060;branch=z9hG4bK-11911-1-0
From: sipp <sip:7816666@hxu.com>;tag=1
To: sut <sip:service@192.168.1.232:5060>
Call-ID: 1-11911@192.168.1.231
Supported: 100rel,timer,resource-priority,replaces
CSeq: 1 INVITE
Contact: sip:781666@192.168.1.231:5060
Max-Forwards: 70
Content-Type: application/sdp
Content-Length:  137

v=0
o=user1 53655765 2353687637 IN IP4 192.168.1.231
s=-
c=IN IP4 192.168.1.231
t=0 0
m=audio 6000 RTP/AVP 0
a=rtpmap:0 PCMU/8000