PABX System?

Question

I wish to ask can any one please explain to me the PABX System? I understand that if for example 1 line has 10 extentions through PABX, does it mean that there could be 10 incoming callers simultaneously calling inbound. May I also ask if two users in a PABX System would like to call at the same time. Can they be able to make a call at the same time? thanks!

Answer 1

PBX's are basically just huge intercom systems with losts of features, one of which is interacting with the outside world.  There are many configurations that allow different levels of useage.  For example, if you have one POTS line (Plain Old Telephone Line) then you can potentially put in on ten internal extensions, but that line will still function the same way: once it's in use by one extension, that's it.  A new caller will get a busy signal, or if someone on another extension tries to pick up they will either barge in on the conversation already taking place or get a notification that all lines are in use.

There are other technologies that do allow multiple incoming and outgoing calls over one circuit, but there is also associated cost.  For example, if your PBX is fed by a PRI circuit, you can basically have 23 phone calls going at the same time.  Since the calls are routed using programming rather than hardwiring, you could potentially have 23 people call your # at once and get through.

So basically, if your using a PBX with your same old telephone service, you'll get the same old telephone service with a few perks on your in house usage.  If you're using your PBX with some of the other available technologies, you get whatever level of service those technologies provide.  The PBX generally cannot affect what the public telephone network does, it can only harness the features provided by that network.