Configure the Number of Concurrent Calls on a Client Access Server


Topic Last Modified: 2012-11-16

You can configure the number of incoming concurrent connections that a Client Access server that’s running the Microsoft Exchange Unified Messaging Call Router service will accept. When you increase the number of concurrent connections on a Client Access server, more system resources are required than if you decrease the number of concurrent calls. Decreasing the number of concurrent calls is especially important on low-end, slower computers on which Unified Messaging services are installed.

The range for the number of concurrent voice calls is 0 to 200. The default setting is 100 and must be configured using the Set-UMCallRouterSettings cmdlet and the MaxCallsAllowed parameter using the Shell. You can’t use the EAC to change this setting. You can also set the maximum number of incoming calls on a Mailbox server that’s running the Microsoft Exchange Unified Messaging service. We recommend that you set the same number of maximum calls on both the Client Access and Mailbox servers.

For additional tasks related to Client Access servers, see UM Services Procedures.

  • Estimated time to complete: Less than 1 minute.
  • You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Client Access server (UM call router service)" entry in the Unified Messaging Permissions topic.
  • Verify that you’ve correctly installed the Client Access and Mailbox servers.
  • For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard Shortcuts in the Exchange Administration Center.
Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server or Exchange Online.

This example sets the number of incoming voice, Outlook Voice Access, and fax calls that can be accepted by a Client Access server named MyClientAccessServer1 to 50.

Set-UMCallRouter -Identity MyClientAccessServer1 -MaxCallsAllowed 50