Audio dropping during calls

[ozydave]

Hello,
Having problems with call audio.
Calls establish but randomly and intermittently the audio between the two parties goes dead and then comes back.
It is affecting internal, internal to external, external to internal and all extensions.

The 3CX is hosted on Azure and we have an internal SBC. the SIP is from gamma.
Gamma cannot find / see any problem there end.

We are a school that goes through our local authority's firewall. I have been on a call with them and they have live monitored the firewall.
During my call with them there were audio issues but nothing showing on the firewall.

I am on Version 20.0 Update 4 (Build 487 Release) of 3CX

What else can I check?

Thank you

 

[SteveITS]

If it’s on internal calls it’s not a SIP provider issue. Try https://www.3cx.com/blog/docs/call-quality-tool/.

 

[NicholasP_3CX]

Use the 3CX connection monitoring tool, to see which side of the connection is at fault

Enable the connection monitoring on a user (top right menu of a user, or from the Team tab



This can monitor a connection for a period of 1, 3, 5 or 7 days

See the report of each call.

This is done through the reports, or through the event log



Click on the log entry to expand the report



here you will be able to see any packet loss and see the quality of the call and which of the 2 sides is at fault.

 

[ozydave]

Thank you, the connection monitor is a handy feature.

This is one of the results, Guess it is not good :-(

 

[NicholasP_3CX]

Definitely does look like a network issue right there. Test it with a 3CX app on a mobile phone using wifi and 4/5G and see if it is something local within your network or something ISP related.

 

[ozydave]

Definitely does look like a network issue right there. Test it with a 3CX app on a mobile phone using wifi and 4/5G and see if it is something local within your network or something ISP related.

Cheers Thats a good call

 

[SteveITS]

Curious, it says "transcoding" even though they are the same codec...?

 

[NicholasP_3CX]

Curious, it says "transcoding" even though they are the same codec...?

That means the call is going through the PBX. If the call is going from one device to another without the audio going through the PBX, then this would show as a bypass call.

 

[ozydave]

Curious, it says "transcoding" even though they are the same codec...?

I am not brilliant with this. I would not know where or why the trans coding happens

 

[NicholasP_3CX]

Cheers Thats a good call

Network engineer by trade mate. Got the scars and the addictions to prove it too.

 

[SteveITS]

That means the call is going through the PBX. If the call is going from one device to another without the audio going through the PBX, then this would show as a bypass call.

Hmm, OK, from PWA to app it shows as "Proxy." So it's more the connection type than the codecs.

With an SBC shouldn't OP's call not go through 3CX? Unless it was being recorded I suppose...

Interesting the "live monitoring" of the firewall didn't notice 10% packet loss...I'd think everyone would notice that. Maybe it's only the connection to the 3CX server...or worse, internal. In which case I'd think everyone would notice that.

 

[ozydave]

So 3CX app to 3CX app installed on mobiles, call quality is good.
3CX on mobile to an internal line then the audio drops.
Assumptions, I have to think its the local authority's firewall, nothing has changed on my internal network. :-(

Of course they say its nothing to do with them. The local authority are the root cause of most of my problems.

Thanks for you help

 

[NicholasP_3CX]

At least now you have data to backup your claim that it is their fault. Ask them for theirs.

 

[ozydave]

At least now you have data to backup your claim that it is their fault. Ask them for theirs.

They are just so bad, no coms from them for two days now. I've sent pcap files screen grabs etc. They are just the worst to deal with

 

[ozydave]

My SBC is version 18.1.36 (windows)
Are there any logs on the SBC that could help ID the problem

 

[NicholasP_3CX]

There is an upgraded version of the SBC, https://www.3cx.com/blog/news/sbc-eol-upgrade/

Try the upgrade and see if it improves. And yes, there are logs on the SBC machine under C:\ProgramData

 

[ozydave]

Cheers thank you