This is a significant update for two reasons. It is the first release of a CU under Microsoft’s new servicing model for Exchange Server 2013. And it is the minimum version of Exchange 2013 required for on-premises co-existence with Exchange 2007 (SP3 UR10) and Exchange 2010 (SP3).
Some important points to note:
- Cumulative updates are a full server upgrade, similar to service packs for previous versions of Exchange, not a minor update like an Update Rollup.
- Exchange 2013 RTM CU1 includes an AD schema update and some AD permissions changes. Read the release notes for full details.
- There is some preparation required for your existing OAB configuration to ensure the new Exchange 2013 OAB that is created does not cause unwanted network traffic.
Aside from the co-existence support and considerations there are also some improvements for existing Exchange 2013 RTM environments.
- Address Book Policy Routing Agent has been included.
- Groups can now be owners/managers of other groups (in a fully supported and easier to manage way)
- Exchange 2013 OWA can now access Exchange 2013-hosted public folders
- A bunch of improvements to the Exchange Admin Center
- Several high availability and manageability enhancements
Download Exchange Server 2013 RTM CU1 here.
Deployment Steps: refer to Installing Cumulative Updates for Exchange Server 2013.