MaxOutstandingSends

HKLM\SOFTWARE\Policies\Microsoft\Windows\Psched

Description

Determines the maximum number of outstanding packets permitted on the system. When the number of outstanding packets reaches this limit, the Packet Scheduler postpones submissions to all network adapters until the number falls below this limit.

Outstanding packets are packets that the Packet Scheduler has submitted to the network adapter for transmission, but which the network adapter has not yet sent.

This entry stores the setting of the Limit outstanding packets policy (Computer Configuration\Administrative Templates\Network\QoS Packet Scheduler). Group Policy adds this entry to the registry when you enable the Limit outstanding packets policy.

• If you enable this policy, the system sets the value of this entry to 1.
• If you disable this policy or do not configure it, Group Policy deletes this entry from the registry.

If the value of this entry is too low, packets can accumulate in the Packet Scheduler when network traffic is heavy. The packet scheduler services packet flows in order of priority or weight.

If the value of this entry is too high, packets can accumulate in the network adapter, rather than the Packet Scheduler. In this case, the queue servicing routines implemented by the Packet Scheduler sequencer have no effect on the order in which packets from different flows are transmitted. However, the system benefits from the optimized performance of pipelining on the adapter.

Change method

To change the value of this entry, use Group Policy. This entry corresponds to the Limit outstanding packets Group Policy (Computer Configuration\Administrative Templates\Network\QoS Packet Scheduler).

Note

This entry is not included in an Administrative Template (.adm) files provided with Windows 2000. To use this entry, you must write a policy and add it to a new or existing .adm file. For instructions, see Advanced topic: Creating custom .adm files in Windows 2000 Server Help.

This entry applies to all network adapters on the computer. You can also set an outstanding packet limit for any particular network adapter by using the MaxOutstandingSends entry in an HKLM\SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\<Adapter-GUID> subkey. If both entries appear in the registry, the adapter-specific entry takes precedence over the policy when configuring that particular adapter.

Tip

For detailed information about particular Group Policy settings, see the Group Policy Reference (Gp.chm) on the Windows 2000 Resource Kit companion CD.

For general information about Group Policy, see Group Policy in Windows 2000 Help.

Related Entries

MaxOutstandingSends