Microsoft KB Archive/181380

= RAS Disconnects Due to Line Noise When Using Multitech Modems =

Article ID: 181380

Article Last Modified on 12/6/2003

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APPLIES TO


 * Microsoft Windows NT Workstation 3.51
 * Microsoft Windows NT Workstation 4.0 Developer Edition
 * Microsoft Windows NT Server 3.51
 * Microsoft Windows NT Server 4.0 Standard Edition
 * Microsoft Windows 95

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This article was previously published under Q181380



SYMPTOMS
After dialing into a Windows NT Remote Access Service (RAS) server, where the RAS server and the RAS client use Multitech MT2834 modems, Windows NT RAS clients and Windows 95 Dial-Up Networking (DUN) clients may randomly disconnect from the RAS server with one of the following error messages:

Windows NT RAS Client
Event ID : 20050

Source : Remote Access

Description: The user  connected on port on at and disconnected on at. The user was active for. <# bytes> bytes were sent and <# bytes> bytes were received. The port speed was 28800. The reason for disconnecting was administrator's request.

Windows 95 DUN Client
You have been disconnected from the computer you dialed. Double-click the connection to try again.



CAUSE
Disconnects may be caused by one of the following:


 * Inactivity Timeout:

If you are being disconnected at a regular interval, the system you dialed may have an Inactivity Timer that is set fairly low (5-10 minutes). For example, if you are reading a Web page through a connection to an Internet Service Provider (ISP) and are not actively doing anything other than scrolling up or down, the Inactivity Timer can disconnect you. -or-


 * Line Noise causing a modem retrain:

If you have irregular disconnect problems (immediate disconnect or random disconnect), you may want to modify the default initialization string on your modem, as Multitech modems will automatically try to resynchronize an already established connection, when line noise or other aberrations affect the quality of the connection.



RESOLUTION
To resolve this issue, use one of the following methods:

Inactivity Timeout
Contact your RAS administrator to increase the Inactivity Timer value.

Line Noise Causing a Modem Retrain
Use the following steps to change the Multitech modem's initialization string on the RAS or DUN client:

Windows NT version 4.0 and Windows 95:

 Click Start, point to Settings, and click Control Panel. Double-click Modems, select the Multitech modem, and click Properties. Click the Connection tab, click Advanced, and type the following in the Extra Settings field:

AT&FX4#F0$R1%E0

 Click OK, click OK, and click Close.

Windows NT version 3.51:

In Windows NT version 3.51, RAS uses a file called Modem.inf in the %Systemroot%\system32\ras sub-directory to send the right communication strings to the modem through the selected modem in RAS. Use a text editor, such as Notepad.exe to open the Modem.inf file. Then find the modem you selected in RAS, and check the COMMAND_INIT string, which is the communication string RAS sends to set up the modem for communication. Refer to the "Modifying MODEM.INF" section in the RAS Online Help program and the modem init string in step three above.

This string will make sure your modem does not initiate a speed change while it is connected because of line noise or other unfavorable conditions. Your modem, will, however, still follow any speed change that the other modem makes. This will ensure that your modem does not cause a disconnect.



MORE INFORMATION
The third-party products discussed here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

Keywords: kberrmsg kbnetwork kb3rdparty KB181380

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