I am a contractor for a national organization and we use Cisco 1721 routers with T1 WIC cards in them. We remote 2 LANs per site. My issue is with these WIC cards. I looked at the spec sheet and the input for these cards are from 1 db0 to 24 db0. I'm not familiar with this db0 reference. Could anyone explain this to me? Also, when we remote these 2 LANS, the only difference is that one goes through a local channel bank. We have problems with the T1 WIC cards hooked up to these LANs. The line keeps going up and down. When we put the T1 WIC card in the router that isn't hooked up to the local channel bank, it works fine. It is hit and miss if the WIC cards work with these circuits and the only difference we noticed is the voltage levels on the T1 cables going into the cards. So I was wondering what this db0 reference was and how it correlates to voltage levels.
