Make sure to install and configure Cisco Unified CallManager 5.x on a Cisco Media Convergence Server (MCS).
Cisco Unified CallManager can also be installed on a Cisco-approved HP server configuration or a Cisco-approved IBM server configuration.
Cisco Unified CallManager 5.0 requires a minimum of these items on the Cisco MCS servers:
These servers are supported without changes:
These servers are supported but require additional memory:
These servers must have their disk drives replaced with a 72 or 80 GB drive and likely require additional RAM:
Refer to these documents for more information: