[SCFN] OT: converting TDM (T1 bundle) to ethernet ?

[Michael Mee]

A little off topic, but I hope you'll humour me ;).

We have a bandwidth quote from a provider that gives us a monthly 
discount for providing our own "TDM" (T1 bundle) to ethernet converter 
vs them supplying it.

What are such devices called and cost and are they a pain to configure? 
I'm vaguely aware that there are TDM modules for Cisco routers but I'm 
hoping there are some black boxes that make it simple(r). (I"ve managed 
to largely avoid IOS so far and am happy to continue to do so! :-) )

Any suggestions?

thanks! michael