Redirector Controller Prerequisites

Redirector Controllers are installed on your Exchange servers to enable dynamic rerouting of messages. Redirector Controllers are required only if your organization will use the optional features described below. Redirector Controllers are installed along with other components in the Aurea Messaging Solutions software package.

For Email Continuity users, Redirector Controllers are necessary for partial activation (a process where some users remain on the primary mail system while others use Email Continuity).

For users of stored mail and Email Archival components, Redirector Controllers are necessary to transfer copies of mail to the VaultBox for processing.

The supported platforms for any machine hosting a Redirector Controller are:

Requirement	Supported Platforms
Microsoft Exchange Hub Transport Agent	Can be installed on any supported operating system and supported Microsoft Exchange version. For more information refer to Software Requirements.
.NET Framework v. 4.5 or newer	Microsoft Exchange 2013 If not already present, you must manually download and install this software.
.NET Framework v. 2.0 SP1 or newer	Microsoft Exchange 2010

Correct placement of Redirector Controller instances (controllers) in your messaging environment is essential for high-availability failover. Much like the domain name service (DNS), the controllers provide routing information to mail servers for active users. Without access to Redirector Controllers, messages for active users cannot be redirected. Similarly, without access to the data center, Redirector Controllers cannot obtain updated routing information for your partially activated mail environment.

Redirector Controller

As part of your installation, Support helps you install a single Redirector Controller in your environment. You can install additional controllers by running the setup and choosing the secondary controller option.

When planning for secondary controllers, consider the following:

• Geographic diversity — If mail servers are available in multiple locations, placing controllers in multiple locations helps protect against catastrophic failure or power outage in a single location.
• WAN topology — Where loss of wide-area network (WAN) links, firewalls, or dial-on-demand links may isolate servers from available controllers, strategic placement of secondary controllers allows Redirector components to obtain updated routing information.
• Geographic redundancy — If your environment includes multiple servers located in a single data center, this magnifies the risks associated with a single controller failure. Consider placing multiple controllers in a single data center.

In the event of an outage where normally functioning mail servers are unable to communicate with a controller (or the controller is unable to communicate with the data center), you may need to activate the service for users on these functioning servers in order to communicate with users affected by the outage. As a result, Support strongly encourages that you critically evaluate the placement of controllers and WAN/Internet connectivity and, where appropriate, add additional controllers, network links, or both to provide the highest possible levels of redundancy.