I have been asked to extend a T1 circuit which is no problem, have done it many times. And then at th last minute they add that they want to do a head to head test (1's and 0's Quasi), and that I can use a router, CSU,DSU for this. In my experience the local Telco does this with a T-Bird or similar device, but am being told a router will be sufficient (as I dont have a T-Bird). I have a 2600 I pulled out of a job recently but am not savvy with Cisco programming, how involved is what they are asking? Should I be able to plug the T1 circuit into the T1 port on the back and thats it....or is there allot more? any help is appreciated.