Configuring System-Wide QoS Settings

After creating a policy, you can edit it by right-clicking it in the details pane of the Group Policy Object Editor and then clicking Edit Existing Policy. You can configure system-wide QoS settings within the Computer Configuration\Policies\Administrative Templates\Network\ QoS Packet Scheduler node of Group Policy. You must modify these settings only if you must limit the outstanding packets, limit the bandwidth that can be reserved, or change the Packet Scheduler timer resolution. The following policies are available in the QoS Packet Scheduler node:

• Limit Outstanding Packets Specifies the maximum number of outstanding packets that can be issued to the network adapter at any given time. When this limit is reached, new packets are queued until the network adapter completes a packet, at which point a previously queued packet is removed from the Pacer.sys queue and is sent to the network adapter. This setting is disabled by default, and you should never need to enable this setting.
• Limit Reservable Bandwidth Controls the percentage of the overall bandwidth that the application can reserve. By default, this is set to 20 percent, which provides 80 percent of bandwidth to processes that do not have reserved bandwidth.
• Set Timer Resolution This value is not supported and should not be set.

The QoS Packet Scheduler node also has the following three subnodes that you can use to manually configure the standard DSCP values:

• DSCP Value Of Conforming Packets These settings apply to packets that comply with flow specifications.
• DSCP Value Of Non-Conforming Packets These settings apply to packets that do not comply with flow specifications.
• Layer-2 Priority Value These settings specify default link-layer priority values for networks that support it.

You will need to change the values contained in these subnodes only if you have configured your network infrastructure to use nonstandard DSCP values.