This article was previously published under Q306037
This article has been archived. It is offered "as is" and will no longer be updated.
Support for the Data Link Control (DLC) protocol has been discontinued in Windows XP. This protocol is not available to install in Windows XP.
If you upgrade from a previous version of Microsoft Windows with the DLC protocol installed, the Compatibility Wizard displays the following message:
The currently installed driver for the DLC Transport Protocol is not compatible with Microsoft Windows XP and will be uninstalled during the upgrade. This protocol is removed from this new version of Windows.
DLC Driver for Microsoft Windows XP is available in Host Integration Server 2000. For more information, visit http://www.microsoft.com/hiserver. Web addresses can change, so you may be unable to connect to this Web site.
For a list of protocols supported by Windows XP, see the Microsoft Windows Whistler protocols Compatibility List at the Microsoft Web site.
The DLC protocol is a non-routable protocol that is primarily used for connectivity in IBM SNA environments for mainframes and minicomputers such as the AS/400. The DLC interface is most commonly used by 3270 terminal emulators to communicate with IBM mainframes.
The functions that are performed by this protocol include error detection (by using a check character), error correction (by using time-outs and retransmissions), flow control (by using delayed acknowledgments and "receiver not ready" response frames), and having multiple devices on the same media (by using polling and acknowledgments).
A Windows XP version of the DLC protocol is available as a free download from the following Microsoft Web site: