Solved Intermittent one way audio - fixed with server restart

[RobertKroll]

I have been running 3cx for 9 years now and for the most part it has been rock solid. Lately, something is going on that seems very strange. The server we are running is on a Virtual machine (Hyper-V) and very recently, once a day or once every other day, the girls from the office call my cell phone and say "We can't hear the person calling in". It has happened that I call my office and I say hello, hello, hello and nothing. I log in to the server from logmein and reboot and voila... I call back and everything is working again.

I have checked the logs, services, etc, and I cannot figure this out. I have also read the forums and I don't see anybody having the same issue. Any help would be appreciated.

 

[eddv123]

Point one - you said it has been running for 9 years now. What version of 3CX is running on the system ?

One way audio is predominately a network issue - for example SIP ALG or ports blocked on your network firewall. As this does not happen all the time this may not be the root cause, but it would be worth running the firewall checker on 3CX to see if it all checks out.

Also can you pin point which types of calls are exhibiting this issue ? do you have a wireshark capture of this and is this an on-premise or hosted 3CX PBX ? I would assume on premise if the system has been installed as long as you say it has.

 

[RobertKroll]

Point one - you said it has been running for 9 years now. What version of 3CX is running on the system ?

One way audio is predominately a network issue - for example SIP ALG or ports blocked on your network firewall. As this does not happen all the time this may not be the root cause, but it would be worth running the firewall checker on 3CX to see if it all checks out.

Also can you pin point which types of calls are exhibiting this issue ? do you have a wireshark capture of this and is this an on-premise or hosted 3CX PBX ? I would assume on premise if the system has been installed as long as you say it has.

Thank you for the quick response. I am running the newest version of the server on a local machine. I have run the firewall checker and it responded that the firewall was properly configured. Internal calls are ok, but outbound or inbound calls are not.

 

[eddv123]

Since the issue resolves with a restart this makes it less of a firewall issue I think.

Are the audio paths traversing between each endpoint or are you using PBX delivers audio on the extensions (commonly set if call recording or using remote phones in the STUN method).

Also what are your endpoints and what firmware are they running ?

 

[RobertKroll]

I just actually ran into the issue and I re-ran the firewall checker and found a bunch of ports are re-mapped. I am going to go into my firewall and see if I can rectify this. I have tried this several times before, but this time I lucked into finding the problem.

 

[eddv123]

Good to see you have found the issue it is always worth a firewall check, please note that the audio ports have been increased recently also: https://www.3cx.com/community/threads/3cx-phone-system-audio-ports-increased.60235/

 

[RobertKroll]

It turns out it was a setting in the network zones on my Sonicwall that must have changed when I upgraded the firmware. I never thought to look there, but the "disable port remapping" check box was unchecked. It was THAT SIMPLE!

Thank you all for the quick help...

 

[eddv123]

Glad to hear your sorted! and thanks for posting up the fix, I am sure it will be useful to other forum users.