BYE not send from the called party.

[3CX_Wave]

In the the following situation, the called party does not send a BYE message when he disconnects from 3CXPhone in Windows, both version 5 and 6. All else works just fine, sound, DTMF tones, conversation,...

User-1 dials the remote server which runs a Dialogic HMP PBX.
User-1 presses 7 to be able to select the user to dial in the IVR.
User-1 presses the 4 digit number of the user to dial.
User-2 receives the call from User-1 and picks up.
User-2 presses 8 to stop the information message from the server.
User-1 is now connected with User-2 and they talk.
User-2 hangs up ⇒ No BYE is sent.
User-1 does not hear anything any more so hangs up. ⇒ BYE is sent to the server. (Normally User-1 drops back into the IVR and can do other stuff)
The server sends a BYE to User-2 as part of the cleanup procedure.

This has been tested where all 3 parties are in different cities.
I attached Wireshark log files from both the server and the users pc (not the same calls) where User-1 calls to himself , which has the same result and has the benefit of having all data in 1 log file.

Is this a 3CX Phone bug or is there a setting I need to adjust ?

 

[3CX_Wave]

It looks like the problem has been solved by setting the outbound caller id on the PBX to the same domain as the Users.
Originally the PBX send “I_am_your_PBX”, the Users where “[email protected]”
Setting the PBX to send “[email protected]” fixed the issue.

The reason why User-1 did not hear anything anymore was due to a test where User-1 dials itself, as a result 2 channels are open on the same softphone and switching between channels makes the sound disapear.
When testing with remote cities User-2 did misunderstand what I meant with not hearing anything.

A new problem appeared during the test.
As long as User-2 has performed a call to the PBX, User-1 can be connected to User-2 through the PBX.
As soon as User-2 logs out/in or has not been contacted in 2-5 minutes he is no longer reachable.

EDIT: This new problem does not occur on my colleague's home computer, so I assume this has to to with the way my NAT works.
I guess a SIP/RTP proxy setup is in order.
EDIT: My NAT is symmetric and possed the above problem, I fixed this using openSIPS and rtpproxy.