Callers or called party report inacceptable Echo

[VodiaUser]

I currently try to use Vodia instead of a 3CX System. While many things do work much better then with 3CX, I have problems with the Android app. One of these problems is that the other party will tell me they are unable to speak to me because of an Echo.

I do not have any options I could choose from to supress this Echo. It does not happen when I use the buiilt in mobile phone. Also when using a real phone there is no Echo.

Is there anything which could be done to fix this?

 

[Vodia Telephone System]

Is it in speaker mode or normal mode when they hear the echo?

Which make and model is the Android device?

What version of the app are we talking about?

Also, when you are in a call, is the native dialer being seen on screen (our app now uses the native dialer) or the app specific dialer is being used?

Thanks.

[VodiaUser]

speaker is in normal mode. The echo also gets wors if I use the speaker mode.
Android device is a Sony XZ1 Compact. Stock Firmware - latest available Andrdoid 9. The Vodia app uses the Systems native dialer, which also jumps in the foreground. However I initiate the call from the Vodia App (originating the call from the native Dialer will not work because there then the Vodia App crashes (I already submittet a the crash report), but that does not make a difference in my opinion.
then I used Linphone for a test. When using this sip client there is no echo at all (regardless of the linphone settings "use software echo cancellation"). 

 

 

[Vodia PBX]

There is actually a new Vodia Android app in the process of getting released, we'll find out how to get it. 

[VodiaUser]

A few more observations:
I tried to set the ILBC codec as the only active codec for mobile apps. However when using the Vodia app for an outging internal call the used codec is anyway PCMA (internal call). When using linphone and enabling only ILBC there is no audio. I then enabled opus. This works with my Deskphone (yealink VP59, it is able to do opus).
Does the PBX include the capability of audio transcoding? Or do I need an extra transcoding software?

Regarding roaming between WiFi and mobile network. The Vodia App seem not to include this capability. Correct? 3CX is able to do roaming during a call, not perfect, but it does.

Missed calls: with 3CX i have about 90% success then using the app. With Vodia about 60% of all calls will be received. 

I like the feature of the Vodia app to use the Andoid phone system. With 3CX initiating a call by tapping a number will instead trigger the native android phone instead of the 3CX app.

What does not work however is clicking a number from a missed call email on the PC. I get a dialogue asking me an authenticaton challenge, but when I enter my credentials it will only ask again. I have to copy an paste the number to make the call.

Using an iphone (2022 SE): No Echo!
 

[VodiaUser]

I found out somethng new regading the Echo: It will also occur if I use the linphone client if I make an outgoing call. If a call comes in there is no echo. The same applies to the Vodia App.
The trunk uses PCMA only. I made a pcap capture. The vodia and the linphone will also use PCMA for the outgoing cal. So, the codec seems not the problem.

I then tried opuc codec for an outgoing Call from my mobile: one way audio: The remote party can hear me, I have no audio. The same for G722.

 

[VodiaUser]

I did some research regarding this problem. I did try to change some settings on the phone in the /vendor/etc/mixer_path.xml. But this was not sucessful. Whatever I change it did not change anything with the echo. Not even I was able to adjust the max. audio volume of the speaker. I think this file is unused.

It ended with trying out different clients.
The built in Android 9 Sip Client: no echo (outgoing or incoming)
Linphone: echo when making an outgoing call
Sipnetic: no echo (outgoing or incoming)
Acrobits: no echo (outgoing or incoming)

For me that means, it is not impossible to achieve an acceptable call quality. It might be related to the phone, but not completely.
I cannot use the Vodia client because 25% of all called people will refuse to speak to me.

[Vodia Telephone System]

Can you please turn on the stand alone mode.

In the app settings, under Sync page, you will find the standalone mode, you can turn it on.

This mode is not recommended because it will not use the android native dialer anymore (with all the benefits), but just to find out if that is causing the issue?

Thanks.

[VodiaUser]

Thank you.

It seems that in the standalone mode the echo problem is not present. I made three testcalls. However only to one person. I should do more tests to be sure.

 

[VodiaUser]

This echo problem, it drives me nuts.

Now, it looks like it is either a Hardware problem of the individual phone, or a firmware problem. About 4 Weeks it started that the Groundwire software also exhibited the echo. Then, I had someone change the battery of this phone and used my spare one (same model, same firmware, same settings restored from a backup). This other phone does not produce an echo, neither with groundwire nor with the Vodia phone app, regardless if the call integration into the android dialer is on or off.

So, maybe the best currently would be to delete this complete thread, because otherwise people might think your software has a problem.

Still I think this is something which relates to software, but if it is related or can be fixed by you/Vodia, I have doubts. My next try if I have some unused time is to make a factory reset of the device, and then upload the current firmware. If this does not help, I go an buy a replacement.

 

[Vodia PBX]

The PBX does not handle echo compensation. 

Because it's a media related problem, I would take a PCAP trace and look at the audio streams. Wireshark can play back each track, and it should be possible to pin point where is the echo coming from. 

Analog phones do generate echo. It's the gateways job to kill the echo and most of them do an excellent job at it. When the analog line is very long, this job gets harder and possibly difficult. But this situation should be really exceptional, for example the analog line somehow gets routed over a long distance with many delays in the middle. 

[VodiaUser]

Of course the PBX is not able to do something about the echo. Either the phone or the App running on the phone has to take care of the echo.

Yesterday I maybe found an explanation: There will be no or less echo if the Opus Codec is used. There is much more echo if aLaw is used.

In Groundwire I am able to choose the codec in the app. The vodia app however has no option. Instead, I should be able to make this setting on the console of the PBX.
This was on of my first problems with vodia: The codec I choose wil be ignored for any call to a caller outside of the pbx. I will always choose to aLaw.

How can I make sure the Voda App uses Opus as codec, always forcing the PBX to transcode?

 

 

 

[Vodia PBX]

If you navigate to the registration tab for an extension, there should be two codec selection boxes. One is for mobile. If you select only OPUS, it should force the app to use OPUS. You can also do that on system level, but I would try on extension level first.