Distorted Prompt from Call Queue after forwarding from Digital Receptionist

[mftIT]

Imagine the following set-up:

1. People call in to the number 0123456789
2. Inbound rules forwards this to the Digital Receptionist 111
3. 111 plays the full intro prompt 'Welcome to ABC.com' which takes 5 seconds.
4. 111 forwards to the Call Queue 211 (If no input within seconds: 1 is set to 'Connect to Queue':211)
5. 211 plays the rest of the intro prompt (Other languages, 'Bienvenue chez ABC.com' etc) whilest trying to ring a recepionist employee.

In this case the intro prompt of 211 is heavily distorted with some noise. However, the prompts are perfectly fine. When calling 211 and 111 directly all the prompts sound fine. Only when 111 forwards to 211, the intro tune sounds wacky.

The reason it was set-up this way is because our company wants that people hear the full welcome in English and afterwards are aided as quickly as possible through a receptionist.
Also, all prompts were converted using the automatic tool on: https://www.3cx.com/docs/converting-wav-file/#h.hmlntlry5ct

Does anybody have experienced the same issue? Is anybody able to replicate the issue?

 

[mftIT]

Hi,
I've got a dump file. If I filter on my phone (sip contains "12..34"), I see some useful stuff, but no errors, but I might be looking wrongly there?

 

[JohnS_3CX]

Now that you have the capture, you want to hear the audio via Wireshark.
Specifically select the stream that has your PBX as the source IP and the provider as the destination IP

 

[mftIT]

Hi, the capture sounds distorted as well.

I've added some arrows on it. Were the red arrows are is where the IVR starts the 'Welcome to our company'. You can see clearly that the sound is played at a fraction of the original volume. The green arrow is where the receptionist answers the phone. At that moment the volume is back okay. Also the instant before the prompt it is played at normal volume and quality.

 

[JohnS_3CX]

Thanks. What server is this running on and what NIC is being used?

Some NICs have been known to mess up SIP.

 

[mftIT]

Hi, this is a VM on VMware ESXi 6.0 on HPE DL380 G9 / MSA2040.
OS is Windows Server 2019 Std, NIC is vmxnet3. (two NICs: one for Domain integration and no GW defined, the other for VoIP with a GW defined)