Why does a hardware conference bridge need a Device Pool
Can someone help me wrap my head around why a hardware conference bridge or transcoder is required to be configured in a Device Pool.
Following typical CCNP examples you have a Device Pool called CorpHQ_DP which has an MRGL of CorpHQ_MRGL, which contains an MRG of CorpHQ_MRG which contains (amongst other media resources) the conference bridge (let's call it CorpHQ_IOS_CFB).
So why do I need to add the CorpHQ_IOS_CFB to the CorpHQ_DP Device Pool when it's created. Why not just add it to the Device Pool through the use of the MRGL under the Device Pool settings. It's like I am adding the CFB bridge to itself.
Is this just something that is done in lab scenarios and in real world scenarios you add the CFB's to their own device pools that don't contain MRGLs which contain the CFB's themselves?