This document describes a problem encountered during a troubleshoot of Cisco Unity and also provides a solution to the problem.
A Microsoft Exchange 2010 cluster has a Conditional Access Systems (CAS) load balancer in use. Unity has issues with the Message Waiting Indicator (MWI) or has issues with access to mailboxes. In order to troubleshoot further, you need to bypass the load balancer. However, due to production issues or other limitations, the load balancer cannot be removed.
As a workaround, you can modify the Unity registry in order to test a specific Exchange CAS server.
- Open the command window.
- Enter the Regedit command.
- Navigate to HKLM\SOFTWARE\Active Voice\AvWM\1.00\.
- Create a new REG_SZ value, and enter the name CAS Server Override.
- Enter the value of the CAS server that you wish to point to as a fully qualified domain name (example: CASServer1.Cisco.com).
- Exit the registry.
- Reboot the Unity server.