Config Motorola DSU/CSU 3512....

[Minh Vu]

Hello all,   I have setup PPP on Cisco router, it works with cross-over cable (without DSU/CSU).  And now, I want implement DSU/CSU 3512 (made by Motorola) between those two router instead of cross-over V.35 cable.   Router1---S0----3512-----cross-over-----3512-----S0----Router2     I have the link (displayed on DSU/CSU) between two DSU/CSU (3512) however on both router the line protocol DOWN and interface UP. So I think I miss config the DSU/CSU.   Has anyone experienced on Motorola DSU/CSU 3512 model ? Can you show me how to config 3512?   I never been config DSU/CSU before so what is the requirement setup should I look for when I config on other DSU/CSU (manufacture or model)       Thanks