Ad-hoc meeting fails when missmach codecs

The issue is happening between HQ and branch office.

Branch phone is unable to call an ad-hoc meeting when codecs in between is G729 and codecs in between branches are G711

Conference Bridge is used default CUCM built-in.

This CFB is software-based which cannot be removed and only processes the meetings with same codecs. In other words, it has to allocate a hardware DSP resources when codec mismatches.

Root cause:

HQ phones and built-in CFB are in the same default device-pool , thus ad-hoc meetings are able to be setup within HQ.

However, phones in branch office are unable to setup ad-hoc meeting because the built-in CFB is in default device-pool, thus branch phones have no permissions to use.

Solution:

Create a new region, rg-codec, for example and configure codec between other regions is  g711u, and then new a device-pool, dp-codec, for example. And allocate above region to this device pool. Finally, have built-in CFB use this device-pool

Because codecs between branch phones and  cfb is g711, branch phones are able to setup ad-hoc meetings.