Data type


Default value


10–65,535 ( seconds )



Determines the duration of the secondary delay used in calculating a time-out value for outstanding operations. If the redirector does not receive a response to an outstanding operation before the resulting time-out expires, it considers the operation to have failed. The value of the SessTimeout entry can be thought of as a margin for error. If there is an unexpected delay, the redirector permits the operation this extra time to complete.

The redirector adds the value of this entry to the expected response time for a server message block (SMB). The resulting time-out is calculated dynamically, and it is approximately equal to:

[(SMB size + Size of data sent or received) / bytes per second] + SessTimeout.

SessTimeout is used for all protocols, including TCP/IP. However, it does not apply to certain types of SMBs, such as transaction commands, that have their own time-out variable in the SMB.

Note Image Note

SessTimeout for Windows 2000 is different from SessTimeout for LAN Manager. In Windows 2000, SessTimeout is just one factor in the time-out equation. In LAN Manager, it is the actual time-out value.