thanks biv343, i got everything configured correctly just like what you explained; except one thing: ENABLE the feature (DUHHH!!!).
so, moving on, i managed to get both BCM & CS1K registered, but there are 2 prominent situation that leads me to believe there's some parts in CS1K not configured quite properly:
1. calls made to CS1K XXXX from BCM client will trigger H323-RAS admissionReq, admissionConfirm between BCM - Gatekeeper; but then CS1K sends CS:ReleaseComplete (reason: gatewayResources)
2. calls made to BCM YYYY from CS1k client will trigger Q.931 signalling initiation from CS1K (??? why???).
i couldn't find a way to disable ISDN signalling in callServer's virtual trunk/route (H323 trunk).
looking at point #1. above, imho, that's an expected behavior, right?
as for #2., what mistakes did i do in configuring the trunking/signalling part?
the plan is to enable peer networking using CDP without any digit manipulation to start with.
any helps would be appreciated.