The only way to allow additional X.25 connections (virtual circuits) is to purchase one or more AppleTalk Remote Access 4 port upgrade(s). This of course gets you a card (which you may not need) but will provide you with the capability of supporting up to 8 virtual circuits per card.
The AppleTalk Remote Access X.25 configuration limits are:
* Up to 8 virtual circuits are support per card up to a maximum of 16 circuits per server.
* You cannot combine modem and X.25 communications links on the same card.
* 4 virtual circuits can be activated per AppleTalk Remote Access license with additional ports available by purchasing additional licenses up to a maximum of 16 ports per server.
The bottom line is, you can only support 16 simultaneous connections per server. With asynchronous based modem connections that would require 4 serial NuBus cards. With X.25 that would require 2 to 4 Serial NuBus cards (depending on how you configure the virtual circuits).