Well, no ones replied because it's not cut and dry. There's a lot the goes into it. How do you want to connect the systems?? IP of point to point's??
For IP, who'll need E&M Tie line cards and MultiTech Gateways. For, Point to Point's, you'll need, T1 cards for the systems for as many T1's to each system.
For IP, you'll need to program the E&M cards. For T1 cards, they'll need to be set up as PRI, and all the protocols need to be programmed for networking under PRI.
You'll need to set up pools for the trunks on the cards.
You'll have to set up a dialing plan. Extensions have to different, a 4 digit plan, and the UDP built.
You'll have to set up calling groups for voice mail for each system as well. But all the remotes will have to have virual ext.'s from the UDP as members of the calling groups. Ane those members will have to be members in the calling group of the centralized VM.
You most likely will have to hire a vendor to do this for you?
KILLBOX