How to Set the Number of Rings for RAS Auto-Answer in Windows NT 4.0/Windows 2000

ID: Q145879

The information in this article applies to:

Microsoft Windows NT Server version 4.0
Microsoft Windows NT Workstation version 4.0
Microsoft Windows 2000 Professional
Microsoft Windows 2000 Server
Microsoft Windows 2000 Advanced 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

By default, the Remote Access Service (RAS) from Windows NT, answers incoming calls after the first ring. The documentation in the Remote Access Administrators Help file describes how you can modify the RAS Modem.inf file to change this behavior. However, this only works if RAS is not using any Telephony Application Programming Interface (TAPI)/Unimodem-based devices.

CAUSE

Beginning in Windows NT 4.0, RAS is capable of using TAPI. It also maintains backwards compatibility with Windows NT 3.51. However, RAS is not capable of using both TAPI and the Windows NT 3.51 Modem.inf information. If RAS is using TAPI, then modifying the Modem.inf file to change the number of rings to wait before answering has no effect.

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).

In Windows NT 4.0, to set the number of ring messages from the modem after which RAS will answer the call, add the following key to the Registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\Parameters

Then, add the following REG_DWORD value to this key:

NumberOfRings

This REG_DWORD registry value can be in the range of 0 to 20. If a 0 value is used, the system does not watch for rings (available since Service Pack 5). If this value does not exist, or is outside of this range, the default value of 1 is used. If RAS is not using TAPI, this value is ignored and the documentation about modifying the Modem.inf file is correct.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

Q221308 NumberOfRings=0 Does Not Work for RRAS Auto-Answer in WinNT4.0

Additional query words: prodnt

Keywords : kbtool ntregistry NTSrvWkst
Version : WINDOWS:2000; winnt:4.0
Platform : WINDOWS winnt
Issue type : kbhowto