Telnet Connection Seems Slow (214432)


The information in this article applies to:

  • Microsoft Windows 98
This article was previously published under Q214432
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256986 Description of the Microsoft Windows Registry

SYMPTOMS

When you use the Telnet tool, the connection may seem slow.

CAUSE

This behavior can occur if you connect to a Telnet server that does not comply with Request for Comment (RFC) 2018.

RESOLUTION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To work around this behavior, disable the TCP Selective Acknowledgement Options (SACK) feature using Registry Editor.

Enter a data value of zero (0) for the SackOpts value in the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MST

Note that you may have to create the SackOpts value. If you have to create the SackOpts value, create it as a string value.

For more information, see page 625 of the Microsoft Windows 98 Resource Kit.

STATUS

This behavior is by design.

MORE INFORMATION

Windows 98 includes support for TCP Selective Acknowledgement Options, as described in RFC 2018, in the Microsoft Transmission Control Protocol/Internet Protocol (TCP/IP). The updated Microsoft TCP/IP provides better performance when it is used in various network topologies and Winsock programs.

The slow performance develops when a remote host attempts to establish a connection with a server that does not comply with RFC 2018. When the remote host attempts to negotiate using the additional TCP Selective Acknowledgement information, the server responds with a smaller TCP/IP packet size. The final result is a very small TCP/IP packet size of 8 bytes that significantly reduces the data flow.

The Microsoft Windows Sockets 2.0 update also includes support for TCP Selective Acknowledgement Options. However, due to implementation differences, it does not display the same behavior. For more information about the Windows Sockets 2.0 update, see the following article in the Microsoft Knowledge Base: Availability of Windows Sockets 2.0 for Windows 95
Modification Type:MinorLast Reviewed:12/20/2004
Keywords:kbprb KB214432
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