Before You Begin
See Planning Your System Upgrade on the Prepare and Plan tab to plan your overall strategy.
Prepare for System Upgrade
To ensure that you have completed upgrade prerequisites, see Prepare for the System Upgrade 
.
Upgrade IPT Software Components
Once you have your upgrade plan and preparations in place, perform your system upgrade following the guidelines and sequence in Upgrading IPT Software Components :
•
See IPT Deployment Models for the general upgrade sequence for the various components in the different deployment models, including IPT Single Site, IPT Multi-site Centralized and SRST, and IPT Multi-site WAN Distributed.
•See Upgrading IPT Components for system-level upgrade procedures for each major upgrade strategy: single-stage system upgrade, multi-staged system upgrade, and multi-staged migration upgrade.
For related documentation on compatibility and component upgrades, see these topics:
•Cisco CallManager Installation and Upgrade Documentation
•Cisco Unity Connection Installation and Upgrade Documentation