2 pbxs interconected


I have 2 asterisks with freepbx interconected with sip trunks. My problem is that when an incoming call from the PBX A enters in the ivr, if the caller try to dial an extension of the PBX B it says “You have entered an invalid extension”.

How can I solve it?

Thanks in advance.

I believe a DUNDI trunk solves this problem. Not 100% sure.

no, i think the problem is the context, the trunk used for the incoming call is an sip trunk with the context from-trunk but i have to use them for limit the number of simultaneus calls

The context would effect inbound calls on the trunks ability to access the internal dial plan.

It would not enable the IVR to route down the trunk. How would the trunk enumerate the remote extensions?

Here is an article that explains how DUNDI works:


You could use the same technique and use ext-local-custom to enable to remote extensions in you IVR.


I should to put in the extensions_custom.conf of the PBX_A:

exten => 2XX,1,Dial(SIP/trunktoPBX_B/${EXTEN})
exten => 2XX,2,Hangup()

the extensions 2XX are in the PBX_B

Is that right or not?

In this case I should delete the outbound route in freepbx 2XX or not?

Thanks in advance

No you don’t need to delete the outbound route.

That didn’t work:

exten => _2XX,1,Dial(SIP/trunktoPBX_B/${EXTEN})
exten => _2XX,2,Hangup()

what did work is the same rules in another context:

exten => _2XX,1,Dial(SIP/trunktoPBX_B/${EXTEN})
exten => _2XX,2,Hangup()