I have a cisco 4000 at my posession. I know it is possible to make this router acting like a frame-relay and/or X25 switch. Recently, I received an NP-4B (4 ISDN BRI outputs) to put into this 4000. Is it possible to make this 4000 acting like an ISDN switch, so i can test ISDN communications. What is the min. IOS and mem/flash.
thanks
Andre
