A couple of other things to note:
1. The ACK message originates from an end point and *not* the proxy. In this case the end point is SIP Broker. The following diagram is from the SIP RFC and should help you visualise:
Code:
Alice's . . . . . . . . . . . . . . . . . . . . Bob's
softphone SIP Phone
| | | |
| INVITE F1 | | |
|--------------->| INVITE F2 | |
| 100 Trying F3 |--------------->| INVITE F4 |
|<---------------| 100 Trying F5 |--------------->|
| |<-------------- | 180 Ringing F6 |
| | 180 Ringing F7 |<---------------|
| 180 Ringing F8 |<---------------| 200 OK F9 |
|<---------------| 200 OK F10 |<---------------|
| 200 OK F11 |<---------------| |
|<---------------| | |
| ACK F12 |
|------------------------------------------------->|
| Media Session |
|<================================================>|
| BYE F13 |
|<-------------------------------------------------|
| 200 OK F14 |
|------------------------------------------------->|
| |
The ACK is sent to the CONTACT defined by the other user agent. In your case, SJ Phone. If you have a look at the 200 OK message just before the ACK you will see that your SJ Phone is sending:
Code:
Status-Line: SIP/2.0 200 OK
Status-Code: 200
Resent Packet: False
Message Header
Via: SIP/2.0/UDP 64.34.163.35;branch=z9hG4bK1e37.1b2efd56.0,SIP/2.0/UDP 64.34.162.221;branch=z9hG4bK1e37.32435635.0,SIP/2.0/UDP 200.152.246.50:5060;rport=5060;branch=z9hG4bK29ec4ad4
Content-Length: 218
Contact: <sip:910198@201.13.48.4:5060>
I'm guessing you are behind a firewall. If so, then I suspect your problem is with SJ Phone STUN handling. There are a few other posts in the forum with people having similar ACK problems using SJ Phone.
.