Multisite WANs with centralized call processing (No CallManager
at remote sites) The Cisco CallManager locations feature is used to
implement call admission control.
Unfortunately, most Cisco CallManager features do not function between
CallManager clusters.You must therefore consider that only the following features
will exist between clusters:
Basic call setup
G.711 and G.729 calls
Call transfer
Call park
Call hold
Calling line ID
Multiparty conference
For this reason, you must take care when designing your IP Telephony network,
in order to reduce unnecessary CallManager clusters.