Server Configuration

Lync servers operate similarly to clients and tag media traffic through the use of policy-based QoS in Group Policy. Each media type has one of the following default port range assigned:

• Audio (49,152–57,500)

• Video (57,501–65,535)

• Application sharing (49,152–65,535)

These port ranges can then be matched through policy-based QoS and assigned a DSCP marking. The default port range for application sharing overlaps with both audio and video. If application sharing is tagged differently than either traffic, a separate port range must be configured. Port ranges for each media type can be configured using the Set-CsConferenceServer and Set-CsMediationServer cmdlets.

For example, to separate application sharing into its own port range, run the following command:

Set-CsConferenceServer –AppSharingPortStart 32768

This changes application sharing to use ports 32,768–49,151 while keeping the same amount of ports available.