Internal and External Calling

We have two satellite sites set up, both have been set up the same way, I assume. I’m coming in from someone else setting these particular sites up.

In our primary site, we can call out, and receive calls no issue including internals. At our secondary site we cannot do any of the above. We can receive calls from our main site but cannot call out. Our sites are on opposite ends of town.

Am I wrong in assuming it’s the firewall at our secondary site is what’s causing the issue?

There is far too little information.

To expand. Asterisk is a PABX construction toolkit, not a PABX. Without knowing how it is being used, and without verbose or debug level logging, all one can say is that a firewall is certainly a possible cause.