Share via

Configure Quality of Service (QoS) for Unified Messaging

  • Article

 

Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Microsoft Exchange Server 2010 Unified Messaging supports DiffServ through Differentiated Services Code Point (DSCP) marking. In Microsoft Windows Server 2008, TCP/IP performs DiffServ marking when you've installed the Quality of Service (QoS) Packet Scheduler. When you install the Unified Messaging server role on a computer that's running Windows Server 2008 with the QoS Packet Scheduler installed, all outgoing Unified Messaging packets will be marked with a DSCP value that's configured using Group Policy. If you're integrating Exchange Unified Messaging and Microsoft Office Communications Server 2007 R2 or Microsoft Lync Server 2010, you can also configure QoS using DiffServ.

Note

Layer 3 network devices, such as routers, must also support DiffServ.

When you create a QoS policy on Windows Server 2008, it will be applied to all UDP packets that are set by the Microsoft Unified Communications Managed API v. 2.0 (UCMA). For more information about how to configure Policy-based QoS, see Policy-based Quality of Service (QoS).

Looking for other management tasks related to UM servers? Check out Managing Unified Messaging Servers.

Prerequisites

The Unified Messaging server role is installed. For detailed steps, see Install the Exchange 2010 Unified Messaging Server Role.

Enable QoS for Unified Messaging

To perform the following procedures, you must log on to the Unified Messaging server by using an account that's a member of the local Administrators group on that computer.

  1. Click Start, click Run, type gpedit.msc in the Open dialog box, and then click OK.

  2. In the Group Policy Object Editor window, locate Computer Configuration/Policies/Administrative Templates/Network/QoS Packet Scheduler/DSCP value of conforming packets.

  3. In the result pane, double-click Controlled load service type.

  4. In the Controlled load service type Properties window, click Enable.

  5. In the DSCP value dialog box, verify that the DSCP value 24 is selected, and then click OK.

  6. In the result pane, double-click Guaranteed service type.

  7. In the Guaranteed service type Properties window, click Enable.

  8. In the DSCP value dialog box, verify that the DSCP value 40 is selected, and then click OK.

  9. Close the Group Policy Object Editor window.

  10. If you want to verify that the DSCP values are set correctly, performing these steps:

    Warning

    Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

    1. Start Registry Editor (regedit).

    2. Locate the following key: HKLM\Software\Policies\Microsoft\Windows\Psched\DiffservByteMappingConforming

    3. The following default values will be set:

      SERVICETYPE_GUARANTEED (DSCP 40, 0x28)

      SERVICETYPE_CONTROLLEDLOAD (DSCP 24,  0x18)

  11. Regardless of whether your environment is integrated with Office Communications Server 2007 R2 or Microsoft Lync Server 2010, configure the registry key to enable QoS marking of IP packets sent by setting the. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RTC\Transport\QoSEnabled key to 1. Then restart the Communications Server 2007 server or the Lync Server 2010 server to load the QoS settings that are stored in the registry.

Enable QoS for Unified Messaging and Office Communications Server 2007 R2 or Microsoft Lync Server 2010

To perform the following procedures, you must log on to the Unified Messaging server by using an account that's a member of the local Administrators group on that computer.

  1. Enable the QoS Packet Scheduler service on servers and clients. By default, the QoS Packet Scheduler service is enabled on Windows Server 2008 computers. However, by default, it isn't enabled on Windows Server 2003 computers. QoS marking isn't enabled by default in Communications Server 2007 R2 or Lync Server 2010 because Communications Server 2007 R2 and Lync Server 2010 only run on Windows Server 2008 and QoS marking depends on the QOS Packet Scheduler service running on both server and client computers.

  2. Configure the registry key to enable QoS marking of IP packets sent to and from the Communications Server 2007 server or the Lync Server 2010 server by setting the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RTC\Transport\QoSEnabled key to 1. Then restart the Communications Server 2007 R2 or Lync Server 2010 server to load the QoS settings that are stored in the registry.

  3. Use Group Policy to set DSCP values that mark the IP packets if you need values other than the defaults for Guaranteed service type packets (used for audio) and Controlled load service type packets (used for video). By default, the following settings are applied when you set the QoSEnabled DWORD value:

    • SERVICETYPE_GUARANTEED (DSCP 40, 0x28)

    • SERVICETYPE_CONTROLLEDLOAD (DSCP 24,  0x18)

For more information about QoS and Communications Server 2007 R2, see Voice QoS.

Other Tasks

After you enable Unified Messaging on an Exchange 2010 server, you may also want to:

 © 2010 Microsoft Corporation. All rights reserved.