Distorted Prompt from Call Queue after forwarding from Digital Receptionist

[mftIT]

Imagine the following set-up:

1. People call in to the number 0123456789
2. Inbound rules forwards this to the Digital Receptionist 111
3. 111 plays the full intro prompt 'Welcome to ABC.com' which takes 5 seconds.
4. 111 forwards to the Call Queue 211 (If no input within seconds: 1 is set to 'Connect to Queue':211)
5. 211 plays the rest of the intro prompt (Other languages, 'Bienvenue chez ABC.com' etc) whilest trying to ring a recepionist employee.

In this case the intro prompt of 211 is heavily distorted with some noise. However, the prompts are perfectly fine. When calling 211 and 111 directly all the prompts sound fine. Only when 111 forwards to 211, the intro tune sounds wacky.

The reason it was set-up this way is because our company wants that people hear the full welcome in English and afterwards are aided as quickly as possible through a receptionist.
Also, all prompts were converted using the automatic tool on: https://www.3cx.com/docs/converting-wav-file/#h.hmlntlry5ct

Does anybody have experienced the same issue? Is anybody able to replicate the issue?

 

[JohnS_3CX]

Hi,

So if you call internally to 111, you hear the 111 prompts fine.
Then you are forwarded to 211, and you hear the 211 prompts fine.

But if you arrive into the PBX from a trunk (calling 012345679) then you hear the 211 prompts garbled.

If this is the scenario you are looking at, then perhaps you need to run a capture while calling in to the PBX from outside, and in the capture you need to hear the audio played via Wireshark and see if:

a) bad audio is actually being sent out from the PBX

or

b) good audio is sent out, YET the caller heard garbled audio once the call went via the trunk and reached the other side


https://www.3cx.com/3cxacademy/videos/advanced/basic-troubleshooting/

 

[mftIT]

Hi,

No. I might have expressed myself short there.
Calling 111 gives the 111 Intro as it should be.
Calling 211 gives the 211 Intro as it should be.

But after the transfer from 111>211 it doesn't sound as it should be (ie. like when calling 211 directly).

 

[JohnS_3CX]

Did you call 111 from an internal extension and wait to be transferred to 211 and heard bad audio?

Or did you call the external line and heard bad audio when you reached 211?

 

[mftIT]

I called from an internal phone (DECT system in this case, but fixed phones act the same) to 111 and 211 seperately.
When doing so, the 211 produces bad audio after forwarding. When calling 211 directly in the same manner, it produces good audio.

When I test it with an external line it does the same (created an additional test-inbound rule for my Mobile).

 

[JohnS_3CX]

Understood. Please repeat your test using the webclient or the windows client, using a fresh extension with absolutely nothing modified

Very important - This in order to eliminate devices being the issue, or config being the issue

 

[mftIT]

Hi, using a WebClient it seemingly works as should be.
Meanwhile I've rebooted the 3CX server and it sounds better. Not good, but better, ie comprehensible audio.

 

[JohnS_3CX]

Thats telling though, because it implies the issue may be with the DECT device or perhaps that changes were made to the codec settings of the PBX or extensions.

Please provide additional information as per the link, and don't forget to include the models of phones you use, the exact firmware version installed on those models, and whether you have provisioned them automatically using our model-specific guides. As you can probably understand there's quite a few variables and we need to narrow them down
https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

 

[mftIT]

Hi,

That doesn't explain why it distorts the sound when calling in from an external line though?

Anyway, we are using SNOM devices:

• SNOM M900 on IPDECT-V2/04.50/B0013/12-Nov-2019 14:03 as antennas
• SNOM M80 on v510.1 as DECT phones

They were provisioned (by me and initially by a 3CX TITANIUM partner) using the model-specific guides.

The rest of the intel:

• 3CX Version Enterprise Annual, 16.0.619
• Server OS, Windows Server 2019 Std
• Is the 3CX Server Hosted and where? Local VMWare/ESXi
• IP Phone Make/Model/Firmware See above
• Provisioning Method: Local LAN
• Trunk Provider or Gateway Make/Model Telenet, Belgium via the 3CX partner
• Has the Firewall Checker passed: YES
• Are custom Phone Templates being used: NO

 

[mftIT]

Anyone?

 

[leejor]

Have you looked over the 3CX Activity Log to see if there is any transcoding involved? The same Codec used throughout...sets, system, and trunk?

 

[JohnS_3CX]

That doesn't explain why it distorts the sound when calling in from an external line though?

I thought you said you tested via webclient and it works ok no?

We need to know if you can replicate it internally using webclient to narrow things down, and if not then we can focus on the external side via trunk (which is a completely different scenario)

 

[mftIT]

Yes, indeed.
I was just wondering how this uses the DECT system.
The only thing working for an incoming call (without someone answering it) is the Trunk and the 3CX server or am I missing the point completely?

 

[JohnS_3CX]

The DECT phone will only become part of the call once the extension answers.

Before that, the call strictly remains between the trunk and the PBX ie. trunk rings, IVR answers call and plays message - depending in how you set up the call flow of course.

But depending also on what codecs you have on the trunk and what codecs you set in Settings > Seneral > Codec Priorities of the PBX

 

[mftIT]

But depending also on what codecs you have on the trunk and what codecs you set in Settings > Seneral > Codec Priorities of the PBX

Ok, clear.
The codec used over there is G.711 A-law.

 

[JohnS_3CX]

So does the issue still happen when somebody calls from an external line and hears the IVR intro?

 

[mftIT]

Unfortunately, yes.
G.711 is the codec that is support by the trunk, so I guess that's fine?

 

[JohnS_3CX]

That's fine, just check that the rest of the system also has that codec on top priority under

Settings > General > Codec Priorities

PCMA = G.711 A-Law



This practically makes sure there will be no transcoding all the way up to the the trunk and IVR.

I expect you should have good audio at that point when somebody dials in.

You should start a capture, dial in from some external line and if the audio is garbled, you can then go check your capture.

In the capture you want to listen to the audio that leaves the PBX IP and has your trunk provider IP as the destination.

If this audio in the capture is clear, yet the external caller heard bad audio, then we will be certain that the issue is not with your PBX at least.

 

[mftIT]

Hi, just checked this. PCMU was the top prio for internal,
GSM > G729 > G722> PCMU > PCMA > OPUS for external.
I've changed it and then tested it by calling with my cell phone to 3CX, but it hasn't changed.
Do I have to reboot the server for this to become active?

 

[JohnS_3CX]

No that won't be necessary, it should apply immediately.

Please make the call again while you run a capture to see if we can confirm the bad audio
https://www.3cx.com/docs/capture-network-traffic/