I have an Asterisk server connected with a Legacy PBX. This setup is connected to another Asterisk Server (In another country) over the Internet with an IAX2 Trunk. Inter Office Extensions are working fine and they can call us and vice versa.
I want to be able to call out from the remote Asterisk server to various Cities - how can I configure my systems to enable that?
To call out you will need one or more phone lines, either physical (PSTN/ISDN/PRI) or voip (SIP/IAX/H323).
The easiest way is to get one or more numbers from a local SIP provider and setup a trunk in your sip.conf. Then is just a matter of configuring your dialplan to use that trunk to call external numbers.
There are lots of examples here.
Is your remote Asterisk box capable of making outbound calls to the telephone network in the country where it's located? If not, you must configure that first (review the Asterisk documentation, and note that you will either need a VOIP provider in that country or Asterix-compatible line cards to connect to the local telephone network).
Once that part is taken care of simply set up appropriate dial plans / outbound routes to recognize when you are attempting to dial a telephone number in one of the target countries, and forward that call over the IAX2 trunk for the remote server to handle.
The exact mechanics of this vary depending on whether you're using straight Asterisk, or one of the prebuilt PBX distributions (like PBX In A Flash or Trixbox) -- If you update your question with more details on your configuration we may be able to give you more specific guidance.
