No audio during calls with 3CX AndroidApp on a specific wifi network

[Bruno PELZER - CELEM]

I have Android devices with 3CX App version 16.0.0.35 that work fine in 4G and WiFi environments.

When I connect those devices in a specific wifi network (hotspot where there is some restrictions), rings, status, registration... works fine but I have no audio during calls and Audio Quality level bars are full white (0%) !
I tested a notebook with WebClient in the same restricted wifi network and WebClient works fine : I only have the issue with 3CX Android App...

To help me to debug this issue, I'm searching someone who know differences between WebClient and AndroidApp regarding audio streams...
Do they use same ports, same codec, same protocols ?
Do you have ideas to debug my problem ?

 

[Evolute IT]

I have Android devices with 3CX App version 16.0.0.35 that work fine in 4G and WiFi environments.

When I connect those devices in a specific wifi network (hotspot where there is some restrictions), rings, status, registration... works fine but I have no audio during calls and Audio Quality level bars are full white (0%) !
I tested a notebook with WebClient in the same restricted wifi network and WebClient works fine : I only have the issue with 3CX Android App...

To help me to debug this issue, I'm searching someone who know differences between WebClient and AndroidApp regarding audio streams...
Do they use same ports, same codec, same protocols ?
Do you have ideas to debug my problem ?

Do you have the 3CX Tunnel configured in your Android app?

The Webclient uses a WebRTC proxy directly onto the server, so it doesn't need the tunnel or a SIP port.

However, the app uses port 5060 when in-office and uses the tunnel (port 5090) by default for out-of-office. If it is disabled, it might explain your issue. Some ISPs block the port 5060.

 

[Bruno PELZER - CELEM]

Thanks Frederick, I'll check but as I know Android App are configured by default.

Another test : same devices but with Android App beta 16.0.4.393 works fine when they are connected to this restricted wifi network but this beta version (16.0.4.393) seems to be unstable on Android 8

 

[JohnS_3CX]

Hi Bruno,

Did you try the tunnel in the end? What was the result?

If the SIP passes but the audio doesn't then the tunnel should indeed help you as suggested above by Frederick (don't forget to reprovision the phone and ensure the tunnel is active).

 

[Bruno PELZER - CELEM]

I leaved all settings by default and "3CX Tunnel" is enabled by default.
It still not work on this specific network (where I cannot change anything ) !

The only one solution I found is to use beta version... It isn't a good solution for production environnent and beta 2 seems ne stable on Android 8 (beta3 is online but I still not tested it)...

It'll be very appreciated if someone has an idea where to search...

 

[JohnS_3CX]

Current Android Beta App is 16.1.0.39
Current 3CX PBX Beta is 16.0.3.671

Can you try using these specific versions + tunnel active?

 

[Bruno PELZER - CELEM]

1. Regarding PBX :
Unfortunately I cannot test with 3CX PBX Beta 16.0.3.671 because the system is in production envirenment and this 3CX install manages about 150 extensions !

2: Regarding Android Devices :
As mentioned before, "no audio problem" was solved with Android Beta App 16.0.4.393 but with this version I had stability problem on Android 8 devices... As you said, there is a new Android Beta version 16.1.0.39 : I'll check if stability is better and if problem is solved with this new Android App version...

 

[JohnS_3CX]

Ok then, let us know how it goes.

Also what PBX version are you using right now for production?

 

[Bruno PELZER - CELEM]

PBX version is 16.0.910
Platform : Debian ISO from 3CX website
Firewall test : green

 

[Bruno PELZER - CELEM]

I captured a wireshark file when a phone has the problem...

• Android smartphone has IP 172.23.0.136 and extension 1229
• 3CX PBX has IP 172.22.0.206

I made a call from Android smartphone (extension 1229) to an external number. External phone rings, I pick it up but I have no audio...



Maybe this capture file will help someone to find the problem...

 

[JohnS_3CX]

Firstly, this is a local call but the client is on a different net than the PBX.

It is not clear whether RTP can pass between the two local networks.

The difference between the android and the webclient is the encryption. This is your hint

 

[Bruno PELZER - CELEM]

OK, as I know the next version of Android App will always use "encrypted tunnel", so I hope my problem will be solved with this new version [And I hope this version will be stable on Android 8 ]

 

[JohnS_3CX]

Hi Bruno,

The 16.1.0.40 app is out now on the beta channel, and stable on my daily Android 8. I'm running it on the new 3CX V16U3 that was released yesterday.

Go ahead and give it a try as soon as you update your PBX.