I am trying to get a better understanding of VPIM and there are good docs on Cisco.com, but still some concepts are not clear.
Lets say you have a network of 10 Unity systems (2 servers per each system) with a bridgehead syste. All servers integrated with Exchange for UM operation.Lets call it cloud A.
Then you have another 10 Unity systems (also 2 servers per each system) with it's own VPIM bridgehead system. Lets call it cloud B.
Cisco docs say that all VPIM configuration should be done on VPIM bridgehead server and then it will be propagated to the rest of Unity servers.
1. Does that imply that Digital networking is used between Unity systems in the same cloud, but when any of those systems needs to forward voicemail messages to Unity in another cloud it will use VPIM?
2. Does it need to happen through bridgehead servers in each cloud, or can Unity (non-bridgehead systems) "talk" directly between themselves in different clouds? Or is it digital networking from non-bridgehead server to a bridgehead server in the same cloud and then VPIM between two bridgehead servers in different clouds and then again digital networking to deliver to a final Unity system (non-bridgehead one) in the remote cloud?
3. When dynamic directory updates are enabled, will subscriber changes picked up by CsVPIMConnector service be propagated from bridgehead server (where CsVPIMConnector is running) to all non-bridgehead servers in the same cloud?