I have configured hardware conferencing on 2921 router, however, it is not getting registered with CUCM version 8.5, I wanted to ask is it mandatory to configure router as MGCP or H.323, is it mandatory to have E1 termination and register the router with CUCM prior to configure conferencing.
No, it is not necessary to use the Router for anything else. You can setup the router to work only as MTP/XCODE/CFB. To look into why it is not registering, a few things to check would be to ensure that you have the sccp profile configured and associated it with the ccm and using the same name on CUCM.
No the H.323 and MGCP are call signaling protocols.
For Hardware CFB, you need resources on your gateway, and apply the correctly configurations on your CUCM and Voice gateway
Take a look on this guides:
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