QoS Tools and Settings
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
QoS Tools and Settings
In this section
QoS Tools
QoS Group Policy Settings and Registry Entries
QoS Tools
The following tool is associated with Quality of Service (QoS).
Tcmon.exe: Traffic Control Monitor
Category
This tool is included in the Resource Kit Tools for Windows 2000, Windows XP, and Windows Server 2003.
Version compatibility
Runs on Windows 2000, Windows XP, and Windows Server 2003.
Tcmon.exe is a tool for viewing and setting traffic control information for local or remote network adapters. The Traffic Control Monitor is a graphical user interface (GUI) tool that interacts with the Traffic Control application programming interface (API).
Several components must be installed for the Traffic Control Monitor to run successfully. The Traffic Control Monitor is installed automatically when Windows Resource Kit tools are installed. The following additional components must be installed separately:
Comctl32.ocx
Msvbm60.dll
Tccom.exe
Note
- Tccom.exe can be called by applications or scripts in Visual Basic Scripting Edition (VBScript) or other scripting languages to remotely configure traffic control on a host.
For information about how to install these components, see Windows Resource Kit Tools Help for Traffic Control Monitor.
QoS Group Policy Settings and Registry Entries
The following Group Policy settings and registry entries are associated with QoS. Each registry setting has a corresponding Group Policy setting. The registry settings appear at four locations in the registry; most of the settings are repeated in three of those locations. The registry structure matches the structure of the Computer Configuration Group Policy settings under Administrative Templates in the Group Policy tool. Each of the tables in this section describes the Group Policy settings and the registry entries in one of those four locations.
The information here is provided as a reference for use in troubleshooting or verifying that the required settings are applied. It is recommended that you do not directly edit the registry unless there is no other alternative. Modifications to the registry are not validated by the registry editor or by Windows before they are applied, and as a result, incorrect values can be stored. This can result in unrecoverable errors in the system. When possible, use Group Policy or other Windows tools, such as Microsoft Management Console (MMC), to accomplish tasks rather than editing the registry directly. If you must edit the registry, use extreme caution.
The registry entries are associated with Windows 2000, Windows XP, and Windows Server 2003. For more information about these registry entries, see the Group Policy Settings Reference for Windows Server 2003.
The following table describes three of the Group Policy settings that are associated with the QoS Packet Scheduler that do not set alternative Differentiated Services Code Point (DSCP) values. These Group Policy settings are located in Computer Configuration Group Policy at Administrative Templates\Network\QoS Packet Scheduler; they control registry entries located under HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Psched.
Group Policy Settings Associated with QoS Packet Scheduler
| Group Policy Setting | Description | Registry Entry |
|---|---|---|
Limit outstanding packets |
Specifies the maximum number of outstanding packets permitted on the system. When the number of outstanding packets reaches this limit, the QoS Packet Scheduler postpones all submissions to network adapters until the number falls below this limit. |
MaxOutstandingSends |
Limit reservable bandwidth |
Specifies the maximum, total percentage of link bandwidth that all QoS-aware applications on this computer can reserve. If no QoS-aware application reserves any bandwidth, then this setting has no effect and all bandwidth is available for use by other applications. If a QoS-aware application reserves more bandwidth than it uses, then the unused, reserved bandwidth is available for use by other applications. The reservation does not ensure that the bandwidth will be available to the QoS-aware application because applications that are not QoS-aware might consume too much bandwidth. For example, the default value of the registry entry reserves 80 percent of the bandwidth for QoS-aware applications, but this does not prevent other applications from using more than the remaining 20 percent of the bandwidth. |
NonBestEffortLimit |
Set timer resolution |
Determines the smallest unit of time, in microseconds, used by the QoS Packet Scheduler when scheduling packets for transmission. The QoS Packet Scheduler cannot schedule packets for transmission more frequently than permitted by the value of this entry. |
TimerResolution |
The following table describes Group Policy settings that are associated with QoS and that set alternative DSCP values for packets that conform to the QoS traffic flow specification. You can use these Group Policy settings to specify alternative Layer-3 DSCP values, which are used by Layer 3 network devices to identify each of five service types. These Group Policy settings are located in Computer Configuration Group Policy at Administrative Templates\Network\QoS Packet Scheduler\DSCP value of conforming packets; they control registry entries located under HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Psched\DiffservByteMappingConforming.
Group Policy Settings Associated with DSCP Values of Conforming Packets
| Group Policy Setting | Description | Registry Entry |
|---|---|---|
Best effort service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the best effort service type. |
ServiceTypeBest Effort |
Controlled load service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the controlled load service type. |
ServiceTypeControlledLoad |
Guaranteed service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the guaranteed service type. |
ServiceTypeGuaranteed |
Network control service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the network control service type. |
ServiceTypeNetworkControl |
Qualitative service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the qualitative service type. |
ServiceTypeQualitative |
The following table describes Group Policy settings that are associated with QoS and that set alternative DSCP values for packets that do not conform to the QoS traffic flow specification. You can use these Group Policy settings to specify alternative Layer-3 DSCP values, which are used by Layer 3 network devices to identify each of five service types. These Group Policy settings are located in Computer Configuration Group Policy at Administrative Templates\Network\QoS Packet Scheduler\DSCP value of non-conforming packets; they control registry entries located under HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Psched\DiffservByteMappingNonConforming.
Group Policy Settings Associated with DSCP Values of Non-conforming Packets
| Group Policy Setting | Description | Registry Entry |
|---|---|---|
Best effort service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the best effort service type. |
ServiceTypeBestEffort |
Controlled load service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the controlled load service type. |
ServiceTypeControlledLoad |
Guaranteed service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the guaranteed service type. |
ServiceTypeGuaranteed |
Network control service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the network control service type. |
ServiceTypeNetworkControl |
Qualitative service type |
Defines the DSCP value that the QoS Packet Scheduler inserts into packets to request the qualitative service type. |
ServiceTypeQualitative |
The following table describes Group Policy settings that are associated with QoS and that set alternative Layer-2 priority values. You can use these Group Policy settings to specify alternative Layer-2 priority values, which Layer 2 network devices use to identify each of five service types. These Group Policy settings are located in Group Policy at Administrative Templates\Network\QoS Packet Scheduler\Layer-2 priority value; they control registry entries located under HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Psched\UserPriorityMapping.
Group Policy Settings Associated with Layer-2 Priority Values
| Group Policy Setting | Description | Registry Entry |
|---|---|---|
Non-conforming packets |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets that do not conform to the flow specification. |
ServiceTypeNonConforming |
Best effort service type |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets to request the best effort service type. |
ServiceTypeBestEffort |
Controlled load service type |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets to request the controlled load service type. |
ServiceTypeControlledLoad |
Guaranteed service type |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets to request the guaranteed service type. |
ServiceTypeGuaranteed |
Network control service type |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets to request the network control service type. |
ServiceTypeNetworkControl |
Qualitative service type |
Defines the priority value that the QoS Packet Scheduler inserts into the Layer-2 header of packets to request the qualitative service type. |
ServiceTypeQualitative |