It depends on how many devices/Gateways/CTI RP you have, if you have IPCC Express or Enterprise, how many Agent will be connected (using CTIOS/CAD...etc.)
There is a Tool called "Cisco Callmanager Capacity Tool" which will help you with capacity planning.
Read also:
[quote]
Cisco CallManager Platform Capacity Planning with IPCC
Many types of devices can register with a Cisco CallManager, including IP phones, IP IVR ports, voicemail ports, CTI (TAPI/JTAPI) devices, gateways, and DSP resources such as transcoding and conferencing. Each of these devices requires resources from the server platform with which it is registered.
The required resources can include memory, processor, and I/O. Each device then consumes additional server resources during transactions, which are normally in the form of calls. A device that handles only 6 calls per hour, such as a standard IP phone, consumes fewer resources than a device handling 30 calls per hour, such as an IPCC agent phone, a gateway port, or an IP IVR port.
In prior Cisco CallManager software releases, Cisco has utilized various schemes to calculate the capacity of a system using device weights, BHCA multipliers, and dial plan weights. These simple schemes have been replaced by a capacity tool to allow for more accurate planning of the system
[/quote]
http://www.cisco.com/en/US/docs/voice_ip_comm/cust_contact/contact_center/ipcc_enterprise/srnd/5x_6x/c5ccmsrv.html
Hope this helps.
Zin Elabidine Karzazi
