There’s documentation available by Microsoft on how to enable Quality of Services (Qo S) in Lync which you can find here.I have a previous article series on enabling Qo S for Lync 2010 here.
You can see Lync Server 2013 client inoperability support here. In Part 2, we’ll add File Transfers, Application Sharing, and SIP to this list just in case you want to provide a more robust Qo S configuration to your environment that extends to more than just Audio/Video. Windows XP uses separate QOS Group Policy Options that do not allow you to restrict the DSCP values at the application level.Windows Vista, Windows 7, and Windows 8 utilize Policy based QOS. This means that all applications that utilize the Audio/Video ports we configure for Audio/Video will get DSCP markings stamped.The legacy Lync 2010 client’s executable name is whereas Lync 2013 now uses the executable name of For Attendant clients, Lync 2010 Attendant is the current solution and the executable name is Attendant The commands are: Note: -Client Media Port Range is used for Office Communicator 2007 R2 Clients.
The reason why this uses 40 is because this setting includes all modalities as Office Communicator 2007 R2 did not split apart each modality into their own separate switches.
So we need to create policies for all three client executables as well as all the executables the server uses.
To help map out what we need to configure, inputting information into the following table will help set the stage for assigning Qo S values for audio and video.
When enabled, clients will use the specified port range for media traffic.
When disabled (the default value) any available port (from port 1024 through port 65535) will be used to accommodate media traffic.
Lync has been designed to work without Qo S but Lync Administrators can choose to enable both Lync endpoints as well as servers to mark Differentiated Services Code Point (DSCP) values on audio and video packets.