Solved No voice from internal to internal when dialing DID's

[RKN]

HI Everyone,

When calling from an extension to the main phone number or any other DID calls are completed successfully (confirmed via active calls) but do not have sound on either side.

Internal to external works
External to Internal works
Internal to Internal works when dialing the ext number
but Internal to Internal does not work when calling main number or DID's

In the enviornment we have a PBX hosted in our cloud datacenter with 3 SBC's deployed on site. All phones connect via sbc except our test which currently only works via app.

I tested different scenario using the 'pbx delivers audio' setting but that didn't help.

This original issue came up when an internal users tried to join a conference call by dialing the DID instead of the ext (500). If users dial the extension number everything works as expected.

Any ideas?

 

[SweetAction]

Does the firewall checker pass?
Do you have restrictions on the RTP port range (9000-10999)?
Which SIP Provider? Any custom settings if a 3CX supported provider?
If you turn on recording, does the audio appear in the recording?

Likely you will need to packet capture this and find out where the RTP stream is.

It really sounds like media from the PBX to the same PBX (via the SIP provider) is failing to be delivered for some reason. My money is something firewall related.

 

[RKN]

Just for future reference, our issue was with network routing. When internal calls were calling internal DID's the outbound traffic was leaving on one public ip, and coming back on a different public IP leaving one way audio. We had to modify our PBX IP to match Bandwidth primary route and that fixed our issue.

Thanks,

 

[OlegR_3CX]

@RKN Hi there, and thank you for the feedback on your issue.
I will now close this thread.