Sound problem when calls go out to the trunk and then come back

[Flash99]

We have a Digital Receptionist assigned to a DID
When anyone calls from outside to the DID number it works normally
When someone internal calls Digital Receptionist internal number also works normally

When we make internal call to the DID number of Digital Receptionist it answers, but there is no sound. Call log shows this call as a call to the internal Digital Receptionist number

Any idea whats wrong?

 

[leejor]

How are you making an "internal call" to a DID number? Normally those calls will come in on a trunk to be able to use a DID rule. How are you dialling? How is it routing? Does the call use a Loop trunk?
Did you assign the SIP ID of the DID, to a dummy extension, that is forwarded to the DR?

 

[Flash99]

Don't ask why , but users need to dial 9 so they dial 9 and the DID number. The call goes out and then comes back via the trunk. I can see the call coming from the trunk in the call log. Probably not the most elegant solution, but it works.

 

[Flash99]

I just checked and actually if any internal extension calls any other internal extension using the DID number the call goes out via the trunk and then back but there is no sound.
Any ideas?

 

[leejor]

It may be one of two things, a port issue, or a Codec issue. Does the Activity Log show any errors at all. The call obviously routes correctly. Have you asked your provider for any assistance< given you are routing the call to them, and them back to you?

Is this a new issue?

If people do this a lot, there are a couple of options. Routing DID calls to a loop trunk, and, the use of a dummy extension (per DID number), with the full SIP ID of the DID number, that is forwarded to the DID extension. the loop trunk will still use two licences per call, but doesn't tie up your outside trunks.

 

[Flash99]

No no errors.

 

[leejor]

What if you call your "main" number from an extension, assuming it comes in on the same trunk group? When you call a DID, and someone answers, is there audio in one direction?

 

[Flash99]

Any number I call (any call that goes out and then comes back) have the same issue
Its a new system, so I don't know if it ever worked or not
I can do a workaround for this, but I prefer to fix it

 

[leejor]

Have you run the 3CX Firewall Checker?

 

[Flash99]

Server and the phones are both on a local network
Calls to any outside number (except our own) work fine. Calls from outside also work fine.
So I don't think it has something to do with the firewall.

Problem exists on both physical phones and soft phones.
PBX Delivers Audio in the extension options also doesn't help

 

[leejor]

I would ask your provider if they could look at a call for you, paying attention to the ports. Running the 3CX Firewall checker will only confirm that all required ports are correctly forwarded.

 

[sip.bg]

This seems being a typical network issue -- outbound traffic to same IP address is sometimes not routed properly by I(T)SP to the same IP address -- the public IP address of the PBX. This typically happens when provider is attempting peer-to-peer RTP traffic between outbound and inbound call from/to your PBX.

 

[leejor]

You could "Wireshark" the calls, comparing a "no audio" call in and out, with working calls out, and working calls in. Of course, that is not going to fix it, but it should show what is different (incorrect port?), which you could then present to your VoIP provider.

Even if your are able to solve this, I would still consider routing these types of calls, in a different manner.