I'm trying to build a dail up internet service company and I was hoping to start small with little overhead. The problem is I need a dail-in voice / data PRI ( pbx ) so potential clients can call via their modems and access my server; where can I go to acquire this service at a low cost

KeepItSimpleStupid

You probably need something like this:

Ras, Remote Access Server, Vpn Appliance, Terminal Servers, Ras Server

The phone company provides the lines and you tell them to seek the next unbusy line. I might be wrong, but I think I remember that in order to support 56K, the modems at the receiving end must be ISDN.

Your access to the internet can be T1, T2, T3 etc, Sonet etc.

retsoksirhc

It's also worth noting that a T1 line is actually 24 Channels which can be divided into separate lines. I don't know the technical details, but I *believe* that, depending on the area, and what type of T1 frameing you get on the line, you may have either 23 or 24 available channels. Some use one channel as the control for all the others (I think it's called a D Channel, or Delta Channel, or somthing...), or uses all 24 channels and has the control built in to the signalling. In either case, yes, you would need a remote access server. I've never looked into it with Linux, but I know windows server 2003 will support dial in clients.

You'd want to make sure you have enough IP addresses for your clients, too. You would have to talk to your ISP about getting those routed to you.