ISDN Server Does Not Answer Incoming Calls (121879)


The information in this article applies to:

  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 4.0
This article was previously published under Q121879

SYMPTOMS

Windows NT 3.5 Remote Access Services (RAS) doesn't answer incoming ISDN calls.

CAUSE

This problem occurs when the phone number (in the Network portion of Control Panel for the ISDN adapter) contains non-numeral characters (for example, a dash "-").

The ISDN driver does not parse non-numeral characters out of the phone number string correctly. This causes incoming calls to be ignored by the adapter.

WORKAROUND

Don't use non-numeral characters in the phone number.

NOTE: When you try to change or remove the phone number, the ISDN setup program does not delete the phone number correctly. If this happens, use one of the following procedures:

Remove and Reinstall the ISDN Adapter Driver

  1. Remove the ISDN adapter driver from the Network portion of Control Panel.
  2. Shutdown and restart your computer.
  3. In Control Panel, add the ISDN driver back without entering a phone number.
  4. Reconfigure RAS and restart your computer again.

Edit the Registry

  1. Start Registry Editor.
  2. In the HKEY_LOCAL_MACHINE subtree go to the following sub-key:

    SYSTEM\CurrentControlSet\Services\Pcimac#

    where # is the network adapter number of the PCIMAC that has been installed.
  3. Under this key there is a Paramters key with the following value(s):

    Line#.LTerm#.Address

    Delete all of the Line#.LTerm#.Address values.

    NOTE: Line# is the line number and LTerm# is the logical terminal number. The PCIMAC - ISA adapter which supports only one ISDN line will only have Line0. The PCIMAC/4 adapter with 4 ISDN lines will have lines numbered from 0 to 3.
  4. Restart your computer.

STATUS

Microsoft and Digiboard International are aware of the problems and are working on a revised driver. We will post more information here in the Microsoft Knowledge Base as it becomes available.
Modification Type:MajorLast Reviewed:5/6/2003
Keywords:kbnetwork KB121879
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