There are ISDN simulators on the market but none are what I would call affordable. Black Box Corp. sells one for about $2500 and Adtran makes one too. I've seen it advertised in magazines but never seen a price for it.
You could probably also do a search on the Internet. I know that lots of folks buy these for CCIE lab preparation. There is probably a pretty good market of used equipment. I know that to be the case with routers and switches.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...