To avoid BES connection latencies and connectivity issues, the Client Access Throttling Policy recommended by RIM is as follows:
By default, Microsoft® Exchange 2010 uses client throttling policies to track the bandwidth that each Microsoft Exchange user consumes and enforce bandwidth limits as necessary. The policies affect the performance of the BlackBerry® Enterprise Server, so you should turn off client throttling for the Windows® account that has a Microsoft Exchange mailbox.
1. On a computer that hosts the Microsoft Exchange Management Shell, open the Microsoft Exchange Management Shell.
2. Type New-ThrottlingPolicy BESPolicy
3. Type the following command:
Set-ThrottlingPolicy BESPolicy -RCAMaxConcurrency $null -RCAPercentTimeInAD $null -RCAPercentTimeInCAS $null -RCAPercentTimeInMailboxRPC $null -EWSMaxConcurrency $null -
EWSPercentTimeInAD $null -EWSPercentTimeInCAS $null -EWSPercentTimeInMailboxRPC $null -EWSMaxSubscriptions $null -EWSFastSearchTimeoutInSeconds $null -EWSFindCountLimit $null
4. Type Set-Mailbox "BESAdmin" -ThrottlingPolicy BESPolicy
The MaxSessionsPerUser value in the Address Book Service is limited by the RCAMaxConcurrency value, which also controls the number of MAPI connections allowed by the service account.
The RCAMaxConcurrency parameter specifies how many concurrent connections an RPC Client Access user can have against a server running Exchange 2010 at one time. A connection is held from the moment a request is received until the connection is closed or the connection is otherwise disconnected (for example, if the user goes offline).
If users attempt to make more concurrent requests than their policy allows, the new connection attempt fails and the Exchange server will log the 9646 event . However, the existing connections remain valid. The RCAMaxConcurrency parameter has a valid range from 0 through 2147483647 inclusive. The default value is 20. To indicate that the number of concurrent connections should be unthrottled (no limit), this value should be set to