1001 Secrets for Windows NT Registry
(Publisher: 29th Street Press)
Author(s): Tim Daniels
ISBN: 1882419685
Publication Date: 12/01/97

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NWNBLink

I-375 NWNBLink provides many extensions to the Novell NetBios protocol. If you use this protocol in a Microsoft-only shop, you can really speed things up with a few registry parameters.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: Extensions
Data Type: REG_DWORD
Value: 1

Changing this parameter tells NWNBLink to use the Microsoft extensions. If NWBLink is communicating with a client using standard Novell NetBIOS protocol, it falls back to the standard version in favor of the extended version.

I-376 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: AckDelayTime
Data Type: REG_DWORD
Value: 250

Windows NT uses this value, which is in milliseconds, when it sends a delayed acknowledgment. You can use this value in conjunction with the AckWindow value, below, to adjust the frequency at which Windows NT must acknowledge frames it is sent. The default value is 250 milliseconds; the value can range from 0 to 65535.

I-377 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: AckWindow
Data Type: REG_DWORD
Value: 2

This value controls the number of frames that are received before an acknowledgment is sent. If you have two computers, one on a fast network and the other on a slow link, adjusting this value can increase throughput. Conversely, if both computers are on a fast link, you can turn off this function by setting the value to 0. You can also let Windows NT determine this value dynamically using the AckWindowThreshold value, below. The default value is 2 and represents the number of frames. The range is 0 to 65535.

I-378 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: AckWindowThreshold
Data Type: REG_DWORD:
Value: 500

This value, in milliseconds, dynamically determines whether it is necessary to send automatic acknowledgments. The determination is based on round-trip time. If this value is set to 0, the NWNBLink uses the AckWindows entry. The default is 500 milliseconds; the range is 0 to 65535.

I-379 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: EnablePiggyBackAck
Data Type: REG_DWORD
Value: 1

Enabling NWNBLink’s ability to piggyback acknowledgments can increase your overall network performance if you participate in two-way NetBIOS traffic on your network. If you set this value to 1, NWNBLink can piggyback acknowledgments when it detects the end of a message. If this value is set to 0, NWNBLink waits the number of milliseconds set in the AckDelayTime before it sends an acknowledgment.

I-380 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\ Parameters
Value Name: RcvWindowMax
Data Type: REG_DWORD
Value: 4

This value determines how many frames the receiver handles at one time. This value is generally set at session initialization to tell the sender the limit of frames it can send at a time. Altering this value can increase throughput and performance.


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