Solved Windows Client => Web Client: Opus Distortion

[Vanburen]

We have a hosted 3CX PBX, where I put Opus as the highest priority codec to facilitate better internal call quality (with PCMA as backup).

When a Windows client user calls a web client user, we are having distortion issues on one leg of the call.

The Windows client to web client leg of the call is fine, however the web client to windows client leg is distorted.

Interestingly however, if the web client user calls the Windows client user, the call quality seems to be fine on both legs of the call.

So the issue seems to only replicate if the Windows client initiates the call.

In the meantime I have disabled Opus on all extensions to ensure call quality is acceptable (all calls work fine using PCMA).

However it would be great if anyone had any advice on fixing this issue? as it would nice to use Opus for internal calls, as we do notice the improvement in call quality.

 

[JohnS_3CX]

Hi,

Check whether you have the options PBX Delivers Audio or Recordings enabled for either of the two extensions you were using during testing. If so, disable the options and recheck

 

[Vanburen]

I just checked and tested again, I can confirm that PBX Delivers Audio and Call Recording are off for both extensions.

Out of interest I enabled PBX Delivers Audio and tested again, this fixed the call distortion issue, however the sound quality is worse, i.e. seems narrowband vs wideband like Opus.

 

[NickD_3CX]

Hi there,
Thank you for reporting this. PBX Delivers Audio should not drop the call quality below, but in addition to this option, you can go to Settings --> General, and here also place Opus in the top row for both internal/external calls.

We will investigate though why there is this quality drop when the PBX Delivers Audio option is off.

 

[Vanburen]

Thanks for looking into this.

"you can go to Settings --> General, and here also place Opus in the top row for both internal/external calls"

I moved opus to the top and the audio quality improved, so I guess it was using PCMA when PBX Delivers Audio was on as a result of it being higher in priority, its good to know this setting takes precedence.

I guess this confirms the issue only happens when PBX Delivers Audio is off.

We tried retesting the Windows to web call quality with PBX delivers audio off as well, to see if changing the opus priority in Settings => General had any impact on our original issue, unfortunately the distortion is still there on the web client to windows client leg.

I guess at least we now have the option of using Opus if we are happy to enable PBX Delivers Audio for all extensions, however I noticed it did lead to extra CPU usage with just one call. So I think we will stick with PCMA for the moment.

 

[NickD_3CX]

Just an update on this, we have identified the problem when calling from the 3CX Windows Client to the WebClient and using the Opus codec with PBX Delivers Audio off and we will be addressing it in one of the upcoming Windows Client updates, so hold tight!

 

[Vanburen]

Many thanks for the update @NickD_3CX. Looking forward to the windows client update!