 | In the properties of the Modem, there is the possibility to define a timeout: that a connection is terminated automatically, if no data (“idle“) has been transferred for a predefined time (often used to ensure, that a user does not forget to hang-up and keeps the line occupied for HOURS). This functionality is NOT executed by the Operating system, but a feature of the modem: the modem itself is programmed to terminate the connection. |
Modem connection (DUN/RAS) is terminating
You have either no idle-timeout defined or you have not yet reached the
timeout value, but the modem-connection is terminated by the system after
a very short time ?
 | the Event-Viewer Logs show the details of the connection. I had a case, where the connection was always terminated after approx. 1 minute. |
I found the Microsoft Knowledge Base article Q164257:
“Inactivity Timeout not Passed Through to TAPI Service Provider“
There seems to be a “bug” in NT 4 workstation and server, that with
some(?) / all(?) modem-types the defined timeout value is not properly
programmed into the modem.
The Knowledge base article offers the workaround to switch-off the
timeout by editing the Registry under the key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
\{4D36E96D-E325-11CE-BFC1-08002BE10318}\000x\Settings:
the Registry-key is usually “0000”, but when you had configured multiple
modems or changed to a different modem, it may be a different value
(like the “0002” in the example above)
The key for “InactivityTimeout” shows for my modem “S30=<#>“
(for my modem, the S-register 30 controls the idle-timeout, it maybe a different S-register for your modem).
 | The article specifies: “set the entry to the desired value”, so I changed it to 250 (since the User’s manual for my modem lists this s-Register to be programmed in Seconds) |
My RAS-server does not terminate the connection quickly or unpredictable,
but now I have a new problem:
My RAS-server does not terminate the connection at all, regardless on
how long the connection has been idle !
(I will keep checking this. If somebody else has a solution, I appreciate to be informed).
