Raspberry Pi SBC / Audio Delay / Dropped Audio

[John Benson]

Dear All

We are using Raspberry Pi SBCs at remote sites where there is only 1 or 2 phones. They connect to our 3CX PBX in a datacentre. They are Raspberry Pi 2 Model B Rev 1.1 running the latest SBC software and connecting to the latest PBX version.

We find that we often get moments where audio stops and the other side thinks the call has dropped. The audio then comes back after a second or two.

If we connect direct using SIP and not through the SBC, the issue goes away.

We have seen this at 3 different sites now.

Has anyone seen this please?

Many thanks

John

 

[Allen_Miller]

All of our Pis are 3s (Bs and B+s) and have not had issues you report.

 

[eddv123]

Very strange especially considering the amount of endpoints you have is way under the guidelines for the Pi.

The audio and signalling should remain local, unless you have the setting PBX delivers audio enabled on the PBX extensions, please confirm this.

 

[cobaltit]

@John Benson

Can you clarify your statement? You say the audio stops for a second and the other side thinks the call dropped. Does the call resume after or does the call actually drop? @eddv123 Is correct to have you check the extensions to make sure 'PBX Delivers Audio' is not checked but either way that shouldn't cause the behavior you are describing unless you lose audio completely and it doesn't come back. And only the audio is kept local with the SBC, the signalling still goes through the PBX..

Are you running the most current SBC version?

 

[eddv123]

With the 3CX SBC yes audio is kept locally. If you enable that "PBX delivers audio " then all audio should be filtered back down the tunnel.

I find this always a good test when experiencing audio issues.

I would be keen to know what the IP handsets and firmware might be?

 

[YiannisH_3CX]

The audio will be kept local if 2 extensions behind the SBC are talking to each other. With external calls the audio will route through the PBX.
@John Benson
Make sure that you are using the 3CX supported firmware and the phones are provisioned using the default template. Also is encryption enabled under the SBC configuration? If it is disable it as a test and try again.

 

[Jordan Bucher]

We have recently started seeing this too on 2 of 3 Pi SBC's ours of Pi3's no amount of updating etc resolves the issue. We do see that a reboot make it's less noticeable for around 4 days.

We will be trialling moving these to a i3 Dell Desktop not a Pi. Will report back.

 

[leejor]

Are the audio issues happening only on calls that go back through the PBX, or, also on calls extension to extension, at the site (both phones behind the same SBC)?