When using the above listed feature - it looks like it requires the use of the "Built-In Bridge" available in some phone models.
When looking at the documentation for using BIB (Built-In Bridge), most of the informaiton I've been able to find I've located in the documentation for using the feature "Barge". In that documentation, it appears that only G.711 is supported.
However, in the above listed link, there's a comment in the documentation that states the following:
"Because the codecs for recording calls match the codecs for agent-customer calls, you may need to insert transcoders if the recorder does not support the matching codecs."
That leads me to beleive that the recording stream codec coming from the phone (destined for the recorder) matches whatever the ACTUAL codec being used for the stream from the agent to the customer is using.
Can anybody comment on what codecs are supported when using the built-in CUCM Monitoring and Recording feature?
The comment about transcoders is needed because the phone's BIB does not provide any transcoding services. The bridge will simply send the tx and rx packets from the existing converstation and forward them to the recorder. If the call is G729 and the recorder supports G711, then CUCM will attempt to insert a transcoder to convert between 729 and 711. ASAIK, when using the recording features, any codec the phone supports will be supported via silent monitor/record...given the fact that a xcoder may be needed to transcode the codec for the target system.
That is correct. The BIB is not restricted to G711, but beware that the BIB does not do transcoding....so all other streams must be of the same type, otherwise a transcoder will be required.