We're planning on spliting our UC environment (CUCM, UCXN, UCCX) across a WAN. By looking at the SRND's for each, I estimate that we'll need 3.7Mbit bandwidth on the WAN just for intercluster communication for all the servers. We have a 6Mbit connection, so that leaves us 2.3Mbit for actual voice traffic if we were to terminate calls on the other side of the WAN from the users.
The region settings between the WAN-connected sites are set to use G.729 for all calls, except for UCCX (this requires G.711, so it has it's own region). My question is, when the call is sent from UCCX to the Agent, will this downgrade the call quality to G.729? Meaning, the only time the calls will be using higher bandwidth is when they are in queue with UCCX (G.711), and once the agent takes them, they will reduce bandwidth to G.729.