Overview: Network I/O Redirection

Last reviewed: September 18, 1996
Article ID: Q103878

Network I/O Redirection

When a device identifier (for example: f:, p:, lpt1:) is redirected to a remote resource in a network command such as

    NET USE F: \\SERVER\SHARENAME

the network software that carries out the redirection sets flags in the operating system's internal device table indicating that the device is remote. File handles for files that are subsequently created or opened on these remote devices are likewise flagged as remote.

When the operating system receives an I/O request--by way of an MS-DOS interrupt x21 or OS/2 API call--directed to a remote device or file, it passes the request to the network redirector instead of calling a local device driver. The redirector formats the I/O request so that it can be understood by the owner of the remote device, the server, and sends it on its way through the network.

The network services provided by the operating system and the redirector generally map to the OSI application layer.

KBCategory: kbnetwork
KBSubCategory: msna

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Last reviewed: September 18, 1996
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