in a centralized CUCM Cluster significant bandwidth is needed for connection of large sites (> 2000 users) to the central applications.
I try to find out, if its better in type of WAN bandwidth and stability
1) to design a Cluster over WAN with local Subscribers and reduce the traffic between phones and Call-Processors but having the Cluster over WAN requirements on the WAN
2) centralize all subscribers
The SRND bandwidth calculations do not
finally judge me.
My feeling says that the Cluster-over-WAN is more batch-traffic and can revover after a WAN failure without large user impact where as the Phone-to-Subscriber traffic is more
real-time and a problem on the WAN
may lead to SRST toggeling, so local Subscribers might be more reliable.
Any comment or better experience is highly welcome...