If you’re trying to contact somebody out on the Public Switched Telephone Network of your Business phone systems and you make a call, it goes into the PBX and then the PBX routes that call out to the Public Switched Telephone Network. So the PBX is basically the server that routes all the calls. Now PBXs are really cool. Like I say, we’re going to have another class on call routing because you can do insane, amazing things with call routing. There are a lot of ways you can route calls. You can put permissions on lines, you can create call groups, hunt groups, just out calling, just a lot of cool stuff, but that will be another class.
The main thing that you have to understand is that the PBX is like the server or maybe the router for your telephone system. If you call another extension in the building, it is what routes the call to that extension. If you call out to the outside world, the PBX is what routes the call to the outside world.
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