U.S. Robotics Courier I-Modem ISDN Modem Does Not Connect at Higher ISDN Speeds

ID: Q238915

The information in this article applies to:
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
  • Microsoft Windows 2000 Server
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

When you connect to an Internet service provider (ISP) with a U.S. Robotics Courier I-Modem, performance may be slow.


CAUSE

This behavior can occur if Windows 2000 has detected that the I-Modem has an older BIOS and has disabled the protocol options.


RESOLUTION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

To resolve this issue, use any of the following methods:

  • Update the modem's firmware. For an external modem, update to version 2.7.6 or later. For an internal modem, update to version 2.1.4 or later.


  • Add *v2=5 to the modem's initialization string. To do this:


    1. Start Registry Editor (Regedit.exe).


    2. Locate the following key


      3. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4D36E96D-E325-11CE-BFC1-08002BE10318}\000x\Protocol\ISDN\V120_64K
      where 000x has a DriverDesc value of "Courier I-Modem ISDN-V.34 Internal."

    3. Modify the "1" value; change the string to include a 5, so that the string reads:


      4. AT*V2=5
    4. Click OK to save the value.


    5. Quit Registry Editor.



STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.


MORE INFORMATION

The value for the AT*V2=x string can range from 0 to 5 for the Data B channel. These values have the following meanings:

0: Autodetect
1: V.120 rate adaptation only
2: V.110 rate adaptation only
3: Modem or fax only
4: Clear-channel synchronous
5: Asynchronous to synchronous PPP conversion

Additional query words: usr

Keywords : kbenv kbhw
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbprb


Last Reviewed: December 29, 1999
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