Exchange Server 2010 : Managing Web and Mobile Access (part 3) - Throttling Client Access, Configuring URLs and Authentication for the OAB

9. Throttling Client Access

Every Client Access server in your organization is subject to the default client throttling policy. Client throttling policies are designed to ensure users aren't intentionally or unintentionally overloading Exchange. Exchange tracks the resources that each user consumes and applies throttling policy to enforce connection bandwidth limits as necessary.

The default policy is set in place when you install your first Exchange 2010 Client Access server. In Exchange 2010, there is a single default throttling policy for the organization. You can customize the default policy or add additional policies as necessary.

To manage throttling policy, you use Exchange Management Shell and the Get-ThrottlingPolicy, Set-ThrottlingPolicy, New-ThrottlingPolicy, and Remove-ThrottlingPolicy cmdlets. Throttling policy applies to:

With all of these features except PowerShell, you can specify separate settings for

Unified Messaging users have the throttling settings of Exchange Web Services. You also can specify the CPU start percent. This value sets the per-process CPU usage percentage at which users governed by this policy will be throttled. Valid values are from 0 through 100. Use $null to turn off CPU percentage-based throttling for a policy.

With PowerShell you can specify:

You can get the default throttling policy by entering: Get-ThrottlingPolicy default* or Get-ThrottlingPolicy | where-object {$_.IsDefault -eq $true}. You can get the throttling policy applied to a particular user by entering (Get-Mailbox UserAlias ).ThrottlingPolicy where UserAlias is the alias for a user, such as:

(Get-Mailbox jimj).ThrottlingPolicy | Get-ThrottlingPolicy

You can create a nondefault throttling policy using the New-ThrottlingPolicy cmdlet. You can then assign the policy to a mailbox using the -ThrottlingPolicy parameter of the Set-Mailbox and New-Mailbox cmdlets. In the following example, you apply TempUserThrottlingPolicy to AmyG:

Set-Mailbox -Identity amyg -ThrottlingPolicy (Get-ThrottlingPolicy
TempUserThrottlingPolicy)

You can modify default and nondefault throttling policies using Set-ThrottlingPolicy. To have a user go back to the default policy, set the -ThrottlingPolicy parameter to $null as shown in this example:

Set-Mailbox -Identity amyg -ThrottlingPolicy $null

You can find all user mailboxes that currently have a particular policy applied using Get-Mailbox with a where-object filter. In the following example, you look for all user mailboxes that have the TempUserThrottlingPolicy:

$p = Get-ThrottlingPolicy TempUserThrottlingPolicy
Get-Mailbox | where-object {$_.ThrottlingPolicy -eq $p.Identity}

To switch multiple users from one policy to another, you can do the following:

$op = Get-ThrottlingPolicy TempUserThrottlingPolicy
$ms = Get-Mailbox | where-object {$_.ThrottlingPolicy -eq $op.Identity}
$np = Get-ThrottlingPolicy RestrictedUserThrottlingPolicy
foreach ($m in $ms) {Set-Mailbox $m.Identity -ThrottlingPolicy $np;}

You can remove nondefault policies that aren't currently being applied using Remove-ThrottlingPolicy. Simply enter Remove-ThrottlingPolicy followed by the name of the policy as shown in this example:

Remove-ThrottlingPolicy TempUserThrottlingPolicy

11. Configuring URLs and Authentication for the OAB

Outlook 2007 and later clients can retrieve the offline address book (OAB) from a Web distribution point. The default distribution point is the OAB virtual directory on the Default Web Site. Each distribution point has three associated properties:

• PollInterval The time interval during which the Microsoft Exchange File Distribution service should poll the generation server for new updates (in minutes)

• ExternalUrl The URL from which Outlook clients outside the corporate network can access the OAB

• InternalUrl The URL from which Outlook clients inside the corporate network can access the OAB

You can configure Web distribution points by completing the following steps:

1. In the Exchange Management Console, expand the Server Configuration node, and then select the Client Access node.

2. In the upper portion of the details pane, you'll see a list of your organization's Client Access servers. Select the server with which you want to work.

3. In the lower portion of the details pane, on the Offline Address Book Distribution tab, you'll see an entry for each OAB Web distribution point configured on the server.

4. Right-click the distribution point you want to configure and then select Properties. This opens the Properties dialog box as shown in Figure 5.

5. On the General tab, set the desired polling interval using the Polling Interval text box. The default interval is 480 minutes.

6. On the URLs tab, the current internal and external URLs are listed. If you want to change the current settings, enter the desired internal and external URLs in the text boxes provided. Click OK.

Figure 5. Configure OAB.