Question : How can I simulate a wide area network serial connection using two 1721 Cisco routers?
I have two 1721 modular cisco routers, with Cisco T1 DSU/CSU WAN Interface Cards. Is there a way that I can simulate a back to back connection like it is often done with 2500 series routers and dte/dce cables?
cisco cables

Best answer:

Answer by Stoner369
Yep.. create a T1 crossover cable.

The wiring is:

1 — 4
2 — 5
4 — 1
5 — 2

Works like a champ! Always keep one in the lab! :D