If you will be using T1's with CSU/DSU's on the ends there is another way to do this. If you connect your CSU's to the AN's, then run a T1 cross connect cable (1 to 5, 2 to 4) between them with one CSU generating timing, the other receiving, you should be able to bring up the 'circuit' between them. We do this with all of our point to point circuits in testing before customer prem install and works wondefully.