Topic Last Modified: 2011-04-11

Differentiated Services code points (DSCPs) mark IP packets with the type of traffic that is contained in each packet. This information is used by QoS to determine the priority of the packet relative to other network traffic. If QoS is enabled on your network, you can take advantage of it by enabling DSCP marking on servers running Microsoft Lync Server 2010 and on Lync 2010 clients. Because Lync Server and Lync clients require that different media use different port ranges, the Windows or Windows Server operating system can identify the traffic type and apply the appropriate DSCP to each packet according to the port that it uses. For details about creating a Quality of Service (QoS) policy for clients, see Creating a Client Quality of Service (QoS) Policy.

All servers that run Lync Server 2010 must be running either the Windows Server 2008 R2 or the Windows Server 2008 operating system.

For Lync Server, you can use policy-based QoS to assign the appropriate priority to each media packet. You will need to create a policy for each traffic type for which you want to use QoS. The procedure for each type is the same; however, the procedure for creating a QoS policy for the Edge Server is different, as described in Creating a Quality of Service (QoS) Policy for the A/V Edge Service.

To create a QoS policy on Lync Server

  1. Log on to the computer as a member of the Administrators group.

  2. Open a Command Prompt window: Click Start. In the Search box, type gpedit.msc, and then press Enter.

  3. In the console tree, expand Computer Configuration, expand Windows Settings, right-click Policy-Based QoS, and then click Create new policy.

  4. In the Policy name box, type a descriptive name for the policy that you are creating, for example, Lync Server Audio QoS.

  5. Select the Specify DSCP Value check box, and then select the DSCP value that you assigned to this media type during the planning phase.

  6. Clear the Specify Outbound Throttle Rate check box, and then click Next.

  7. If this policy will apply to all applications, click All applications. If it will apply only to Lync Server, click Only applications with this executable name. In the box provided type the name of the executable file for the server application, and then click Next.

    The executable file names for the applications for which you can enable QoS include: ASMCUSvc.exe, AVMCUSvc.exe, MediationServerSvc.exe, and OcsAppServerHost.exe. For details, see Planning for Quality of Service (QoS) in the Operations documentation.
  8. Allow the policy to apply to all source and destination IP addresses (the default), and then click Next.

  9. In the Select the protocol this QoS policy applies to box, click TCP and UDP.

  10. Under Specify the source port number, click From this source port number or range. In the box provided, type the port range for the media type that you specified during planning, and then click Finish.

You will need to restart the server for the changes to take effect.

See Also