Call is muted during initial 2-3 seconds of call

[NSR]

When a call connects there is a brief delay before anyone can speak. Half their initial greeting is cut off. Once this muted period has ended, there is no delay between speaking and the audio on the other line. It appears the mute lasts only the first few seconds, so my users have to pause before performing their initial greeting. This happens on internal calls - extension to extension on the same network - and also inbound/outbound external calls.

We have a V20 system self-hosted in Azure, build 715.

 

[NicholasP_3CX]

This could be one of 2 things.

1. Either the confirmation of the call being answered is delayed from the provider. You can test this with a wireshark capture and seeing if those 2-3 seconds of audio is in the capture.

2. Do you have recordings enabled on these calls?

For a call to be recorded it needs the confirmation from the disk that it is OK to start recording. If it is a mechanical disk by the time it spins up and gives the OK, this could cause a delay.

To test this, disable recordings on an extension for a test and try to replicate.

 

[NSR]

For a WireShark capture, would you recommend using the "Capture" feature on the dashboard? I believe this is actually tcpdump, since it's a Linux box. Or should I run a WireShark capture on the phone itself?

Under Admin > Recordings, it appears we have call recording disabled.

 

[NicholasP_3CX]

For a WireShark capture, would you recommend using the "Capture" feature on the dashboard? I believe this is actually tcpdump, since it's a Linux box. Or should I run a WireShark capture on the phone itself?

Under Admin > Recordings, it appears we have call recording disabled.

View attachment 42908

That is showing you have the recording archiving disabled.

The recordings are configured under the users options.



We have also made it easy to do a capture from the PBX interface itself.

No TCPDUMP or TSHARK required.

Just do it from the interface.



Mine here is disabled as I am using a Hosted by 3CX instance, but on yours it should be enabled since you are self hosting on Azure.

You should then be able to see the DTMF key presses in the capture.

 

[NSR]

Ok - I've confirmed that call recordings are disabled, and we've never had them enabled.

I'll give the capture feature a try and report back.

 

[NSR]

I captured 22 seconds of traffic, which should include the initial moments of a call. It's 3000+ lines, and I'm not exactly sure what I'm looking for. Does 3CX have any tips on interpreting its Wireshark output?

 

[NSR]

I was able to use Wireshark to produce a visualization of the call. There is a 3-4 second period at the start of the call where there is almost no audio. I spoke to another user, and they said that they always start talking immediately and never notice a delay. I verified that I could hear her as soon as she picked up the phone. She is also the only one who does not use a wireless headset to answer their phone. I'm going to do further testing on headset vs. no headset and see if that's where my problem resides.