Microsoft KB Archive/90180

= NCB Performance and Piggybackacks =

Article ID: 90180

Article Last Modified on 10/31/2006



This article was previously published under Q90180



SUMMARY
On file servers and workstations that are heavily used, be sure that PIGGYBACKACKS is set to 1 (default value, ON). When &quot;piggybacked&quot; acknowledgments are used, a computer that receives a request for data can send an acknowledgment of the request and the data itself in the same frame, cutting down on network traffic overhead. Using piggybacked acknowledgments increases file-transfer performance.



MORE INFORMATION
Tests indicate poor performance when you send data in one direction only or do a very simple send-wait-receive ping-pong with piggybackack turned on. This occurs because the receiving NetBEUI stack does not send its acknowledgment until the T2 timer pop, thus slowing the network traffic.

By turning PIGGYBACKACKS off, these tests perform as expected.

In real-world scenarios, PIGGYBACKACKS should be left on. In most cases, data is transferred in both directions and is not contingent on the completion of an earlier request. Turning PIGGYBACKACKS off will result in higher network traffic and degraded performance.

Additional query words: 2.0 2.00 2.1 2.10

Keywords: KB90180

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