Topic Last Modified: 2013-11-07

Quality of Service (QoS) is a networking technology used in some organizations to help provide an optimal end-user experience for audio and video communications. QoS is most-commonly used on networks where bandwidth is limited: with a large number of network packets competing for a relatively small amount of available bandwidth, Quality of Service provides a way for administrators to assign higher priorities to packets carrying audio or video data. By giving these packets a higher priority, audio and video communications are likely to complete faster, and with less interruption, than network sessions involving things like file transfers, web browsing, or database backups. That's because network packets used for file transfers or database backups are assigned a "best effort" priority.

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As a general rule, Quality of Service applies only to communication sessions on your internal network. When you implement QoS, you configure your servers and routers to support packet marking; however, you configure these devices to support packet marking in a particular manner. You cannot assume that Quality of Service will be supported on the Internet or on other networks. Even if Quality if Service is supported on other networks, there is no guarantee that QoS will be configured the same way that you configured the service on your network.

Microsoft Lync Server 2013 does not require Quality of Service; if you do not currently use QoS there is no requirement that you install the service before installing Lync Server 2013. If you experience a considerable amount of packet loss on your network the recommended way to alleviate this problem is to add additional bandwidth. If adding more bandwidth is not possible, then you might want to implement Quality of Service instead.

Lync Server 2013 offers full support for Quality of Service: that means that organizations that are already using QoS can easily integrate Lync Server into their existing network infrastructure. In order to do this you must perform the following tasks:

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If you are using Microsoft Windows Server 2012 or Windows Server 2012 R2 you might be interested in the new set of Windows PowerShell cmdlets available for managing Quality of Service on that platform. For more information, see Network Quality of Service Cmdlets in Windows PowerShell at http://go.microsoft.com/fwlink/p/?LinkId=285379.