ISDN Channels Config Q?

[Aditya]

Hi,   Im working on a 1603 router. I have to configure DDR using ISDN to two different locations. When I try to go to the interface config mode BRI 0:1 or BRI 0:2 it gives an error message saying "cannot configure the BRI Channels" .. (Im not shure of the exact words, but it meant this). Only BRI 0 works.  Can we use Cisco 1600 series for dialing to multiple locations (the channels dialing different locations?).   can any one give a bit of explanation on the error messages and solution if any?. Any help will be appriciated.   Aditya Kedia Network Engineer.