Two important factors that drive your business requirements are:
•
Call flows
•Installation requirements—upgrade or new installation
Review Step 1: Determine Your Requirements 
of the Deployment Methodology chapter in the Cisco Unified Communications System Description.
Understanding Call Flows
Refer to the topic Understanding Call Flows on the Prepare and Plan tab.
New Install or Upgrade
If you are a new user, see Install and Configure System Components.
If you have implemented IPC System Test Release 4.1 and you are upgrading or expanding your system, see Planning Your System Upgrade.
After you have planned your upgrade, see the Optimize tab for information on Performing a System Upgrade.