Audio issue with retrieved call parks from pstn

[Keith T Atwood]

Having an issue by when any call through our Patton fxo gateways are put on park, when the call is retreived there is no audio. The shared park works fine with the internal yealink to yealink phones. I’ve unchecked Supports Re-Invite" and "Support Replaces" from the trunk, but that causes there to be no audio on all in/out Patton pstn calls.

Everything is up to date software and firmware wise.

 

[leejor]

Put a call on hold, allow this (no audio) to happen, terminate, then check the 3CX Activity Log. Any errors/logs regarding Codecs, or ports? Are you using a prefered HD Codec (or something other than G711 a/u) on the sets, that is not used (missing) in the Gateway?

 

[eddv123]

What is the model of Patton, is it s Smartware device (supported) or Trinity (currently not supported) ?
If it is a 4110 series FXO then it will be a Smartware.

Both work with 3CX regardless however certain caveats need to be followed for the Trinity gateways. If you want to run a PCAP trace I would be happy to take a look at the audio streams for you.

It might also be worth turning on "PBX Delivers Audio" in the Gateway configuration on 3CX, this normally is disabled if I recall by default.

Also where is 3CX in relation to the Patton - on premise, VPN etc ?

 

[Keith T Atwood]

So a bit more info. The problem is not isolated to the shared parking on pstn calls. There is also a problem recording digital receptionist recordings. The system allows you to make a new recording, but the recording is silent. If we make a 10 sec recording and play it back, we hear 10 sec of silence. (Even if we download the wav file, it will be 10sec of silence)

I've attached 2 packet captures.

PARKING DUMP
Shared parking capture events.
Ext 7501 calls 807738xxxx
call is established
Ext 7501 places call on shared park 1
Call is picked up on ext 7500
call is established between 807738xxxx and ext 7500
no audio
hang up
https://drive.google.com/file/d/1tmvar-Q6PtvX2Pk7-hNsK-O6RhkYaXj0/view?usp=sharing


IVR DUMP
Setup new digital receptionist
record message using ext 7500
ext 7500 rings, i answer and follow prompts to record
i recorded the message twice and pressed 0 to save
hang up
play back the message, just plays silence


FYI: The Patton is a Smartnode (fully supported), the pbx (windows 10 HPE micro server), Phones (yealink t58 and 2x yealink t41s, 2x grandstream gxw4248 are all directly connected to the same switch(cisco sg300 poe switch)

 

[eddv123]

Before I start can I confirm you have checked and tried the "PBX Delivers audio" setting on the gateway ?

With that being said this is just an internal "record file" audio issue - so for example (and please confirm) from the call flow all that I can see that is happening is that the PBX (172.20.20.20) is sending a recording request to in this case a Yealink T58.

The audio in this case should not go anywhere near the Patton gateway as it is just internal. You could then in this case (as a test) confirm the "PBX Delivers audio setting" on the extension you are testing on (look under options).

I can definitely confirm that no audio path is not present in the trace you have sent but that does not mean it wasn't sent. With on premise PBX's when a SIP call sets itself up it will pass the audio traffic endpoint to endpoint, the above setting will change this behaviour so worth enabling it and re-taking the capture if the issue still exists.

 

[Keith T Atwood]

If i enable "PBX Delivers Audio" I will get no audio on that device. For example, If i enable it on the patton, there is no audio on pstn calls. If I enable it on an extension, then that extension has no audio on all calls, internal and exernal. If i enable it on everything, then there is no audio anywhere.

Another discovered issue. DTMF tones were not working properly internally (i.e. would not accept voicemail PIN) it was set to rfc by default in the yealink phones. I changed this to rfc + SIP Info and the issue was resolved.

It sounds like the 3CX PBX is not able to handle the RTP Audio streams. When the patton talks directly to the yealink, things work. When the call is places on park, the PBX takes the calls and then when the call is retrieved off park the audio is lost because the PBX was involved in the RTP Audio. The DTMF tones worked externally through the patton using rfc because the PBX was not involved, but internally the PBX could not hear the rfc dtmf tones. I changed to sip info (which I assume is not an RTP payload) and then DTMF tones work internally.

Something is broken in the PBX. It was a new build just put into production. I had originally installed 3CX a month ago using 3 digits. I needed to change this to 4 digits, so I uninstalled and reinstalled 3CX with 4 digits. There were no errors or issues with the install or configuration.

 

[eddv123]

From your description I would agree that the PBXand RTP sounds to be the area you need to look.

SIP traffic is flowing correctly as RFC 2833 DTMF is sent in its own separate RTP stream (The legacy inband method sends in an already established stream) where SIP INFO goes via SIP signals.

Beyond running a port scan on the server for the local RTP ports, checking for local firewall or anti virus software I think it maybe a good idea to remove and reinstall perhaps.

 

[Keith T Atwood]

No firewall is running on the Windows 10 PBX, no antiviurs, It's a clean Windows 10 Pro install with only 3cx installed. No hardware firewall between the devices. If the switch was an issue, it should also be affecting RTP streams between the patton and phones (which are working fine). My plan is to fire up a new Windows 10 Pro system and do a clean install of 3cx and restore the backup (without license) from the production system to see if the problem is still there.

One question. For this new PBX build I will need to get a trial license installed to get it running and do the restore (without license). If all is good, I will need to replace the trial license with their production license. Is this possible? I cannot restore their current license into the test system as it is already running onsite.

What's the best strategy to do the flip?

I'd prefer to just get things running on a new system and then pull out their current system.

Thanks!

 

[Keith T Atwood]

Ok. I built a new system with trial license and updated to the newest release, restored from backup and everything works.

I think I now know what caused the issues. When I did the most recent 3CX update on the production system, there was a windows update that caused a premature reboot of the computer before the update was applied. I remember having to do the update again after the reboot. I thought the 2nd time I did the update it would fix the premature 1st attempt. This is the only thing I can attribute to the root cause.

I guess at this point I’m best to just do a backup, remove and reinstall 3CX, restore from backup, do the latest update and then do another restore ( FYI, the restore will not work on the 1st time setup wizard because of a version mismatch) I had to restore during wizard, which showed no extensions or configuration. I then did the beta update and did another restore, which then populated the configuration.

Thoughts?