DID to DID Calling Two Different Trunks on same PBX Instance

[Ben Crawley]

I have two Flowroute trunks on the same PBX instance. A user from one department will have calls that will not call through to the DID on the other trunk.

Essentially Trunk 1 DID user can't call Trunk 2 DID user if that makes sense. It will ring a couple times and then give a busy signal. These are two different companies on the same owners PBX instance. Trying to determine why calling the DID will not allow the call to go through.

Thanks

 

[Kevin Attard Compagno]

Somewhere in the SIP flow, the call is being stopped in its tracks. Use a SIP capture to get some insight about that. With that in hand, you should be able to either get closer to the root cause, or possibly ask your provider to look into it.

 

[KyriacosS_3CX]

This might even be an issue on the SIP Trunk provider site, looping back calls to the same IP. If you are not talking about a massive number of DIDs, a Null/localhost trunk and some Outbound rules might be able to fix it.

 

[Ben Crawley]

No it's just one company's DID to the other company's DID but yes it's coming back to the same instance's IP.

Can you expand on Null/localhost trunk and the outbound rules?

 

[KyriacosS_3CX]

To set up a loopback trunk for internal DID calling in 3CX, follow the general steps below - this of course will mean that your panel will give you a warning about an unsupported trunk, but should not have any other impact.

Configure a SIP Trunk for Loopback:- In the 3CX Admin Console, go to `Voice & Chat`.- Click on `+ Add Trunk` and configure a new IP SIP trunk.- Assign a new loopback address (usually 127.0.0.1 can be used for internal routing).

Outbound Rules Adjustment:- Adapt your outbound rules to use this loopback trunk for internal calls. Create specific rules that will route calls intended for internal extensions through this loopback trunk.

Check Routing and Matching:- Verify that the DID numbers you're trying to call internally are correctly formatted and matched against the rules you've set up. Use the 3CX Dashboard to monitor active calls and ensure correct identification.