Table 1-4 Recommended Call Processing Agents
Call Processing Agent Recommended Size Comments
Cisco Unified Communications Up to 240 phones For small remote sites.
Manager Express (Unified CME) Capacity depends on Cisco IOS
platform.
Cisco UCM 50 to 30,000 phones Small to large sites, depending
on the size of the UCM
cluster.
Supports centralized or distributed
call processing.
Legacy PBX with VoIP gateway Depends on PBX Number of IP WAN calls and
functionality depend on the
PBX-to-VoIP gateway protocol
and the gateway platform.