File Transfers Between Computers Are Slower Than Expected (241672)
The information in this article applies to:
- Microsoft Windows NT Server 4.0
- Microsoft Windows NT Workstation 4.0
This article was previously published under Q241672 SYMPTOMS
File transfers between Windows NT 4.0-based computers with similar names are slower than expected. A network trace shows that the data transfer size is 512-byte increments, rather than the 4,096-byte or larger default size used by Windows NT.
CAUSE
A problem in the redirector (Rdr.sys) causes the workstation to incorrectly mark a connection to a remote server as "loopback." This occurs when the remote server has a NetBIOS name that is a subset of the local NetBIOS computer name. For example, a connection to a server named Test is incorrectly considered a loopback connection from workstations named Testx, Test1, Testabc, and so on.
The redirector treats loopback connections differently than it does remote connections. On connections to remote servers, the redirector makes an initial read or write request of 512 bytes and then increases the request size if both computers are capable of handling larger requests. On loopback connections, the entire transfer is in 512-byte increments. Making these small read and write requests generates network overhead, and the request takes longer to finish.
RESOLUTIONA supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site: NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
The English-language version of this fix should have the following file attributes or later:
Date Time Size File name Platform
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09/14/99 01:08p 265,008 Rdr.sys Intel
09/14/99 01:07p 512,144 Rdr.sys Alpha
STATUSMicrosoft has confirmed that this is a problem in Windows NT 4.0.
| Modification Type: | Minor | Last Reviewed: | 9/23/2005 |
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| Keywords: | kbHotfixServer kbQFE kbbug kbfix KB241672 |
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