Codec Question

[Colin911]

I have an unsupported Trunk because none of the supported ones work in my region. Despite paying for a support ticket, 3cx are refusing to help me diagnose this issue despite having paid them, so I'm hoping someone in the community can (Happy to pay too but it seems even the paid solution is not available so far).

I have a SIP trunk that has been running for a few months and yesterday it stopped. The engineers at Digicel are asking the below question:
"The PBX is having issues negotiating Media Codecs and is potentially not choosing one media codec to use to negotiate the call and as such is confusing the MSC and the MSC is dropping the call. Please use the attached to reference the points below.

• line 309 is the invite form the SBC to the PBX with the Codec negotiation
• line 319 is the 200OK coming in from the PBX with the SDP. Contents show multiple codec offers instead of just one. As such the MSC doesn't know which one to choose to use for the call so it drops the call."
  
  
  Exceprt from the Pcap:
  

 

[SteveITS]

Can you just remove any other codecs from the trunk? Edit trunk, options tab, codec priority:

 

[ivank]

PBX sent back zero audio port thus disabling audio completely. This went unnoticed by "the engineers at Digicel".
Check if the user who answered the call has Options > SRTP Mode set to "Enforced".

Enable verbose logging, repeat the call and study 3CXMediaServer's log file. If you're lucky, there will be some warning/error message that points in right direction.

 

[Colin911]

Thank you for your answers! Much appreciated. Waiting for their response.

 

[Colin911]

PBX sent back zero audio port thus disabling audio completely. This went unnoticed by "the engineers at Digicel".
Check if the user who answered the call has Options > SRTP Mode set to "Enforced".

Enable verbose logging, repeat the call and study 3CXMediaServer's log file. If you're lucky, there will be some warning/error message that points in right direction.

HI ivank (or anyone else). Do you mean to have SRTP enforced on the final extension that will be receiving calls from this trunk? We've never had this...

Currently trunk forwards to a Queue to which many users are assigned.

 

[Colin911]

It seems the issue was due to a Certificate. The certificate was removed and the trunk now works.