You may know this stuff already, but just in case:

You'll need a PRI enabler code from your Nortel Vendor. Then you need to turn that back into the vendor with the system ID to get the actual key code (24 digits) that you enter into the system. If you don't so this, you won't be able to get the T-1/PRI to work on the system.

Disable the card (module status) then change the card type to PRI (hardware), then re-enable the card (module status)

In LINES menu: DID's (target lines) start at Line 157. I use this as the main company number usually and then start the private DIDs at Line 158 and up.

Set the received digits in System Programming
menu.

Clear line pool /external code "9" from system programming.

Create Destination code "9" to use route 001
set route 001 to use PRI A

Give all sets access to PRI A (terminals and sets)

Clear the control set for all DID's other than the main company line (line 157) so the attendant doesn't send all line to the AA system when engaging night mode.

In F983, tell the system to answer line 157 at 4 rings and make sure lines 1-23 are set to answer = NO.

Set up ringing to sets in terminals and sets just like any other line, just select line 157, 158, etc. You should probably make it appear and ring with multiple appearances of the DID. If you try to make it ring only, the calls don't stack up on the intercom keys like you would expect.

I'm sure there's more to it, but off the top of my head, that's a good start.

Punch down all your damn pairs!..........(please).