DOCUMENT:Q252299  08-MAY-2002  [winnt]
TITLE   :RAS Service Cannot Receive Calls over the COM Port
PRODUCT :Microsoft Windows NT
PROD/VER:winnt:4.0 SP3,4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
OPER/SYS:
KEYWORDS:kbnetwork kbWinNT400PreSP7Fix

======================================================================
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The information in this article applies to:

 - Microsoft Windows NT Server versions 4.0 SP3, 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a 
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SYMPTOMS
========

If you disconnect and reconnect a modem cable and a you receive a call within a
few seconds, the RAS service could lose the COM port. Other calls coming over
that COM port are not answered by the RAS service.

These problems also occur on RRAS.

A RAS client (X.25) connects and disconnects in the middle of the call, after a
few tries RAS Service loses the COM port and does not receive any calls.

CAUSE
=====

This issue can occur if your computer has other kernel mode drivers that do COM
port emulation.

RAS/RRAS does not check if a call is in progress when posting a listen command.

RESOLUTION
==========

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the
fix. For a complete list of Microsoft Product Support Services phone numbers and
information on support costs, please go to the following address on the World
Wide Web:

   http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

The English-language version of this fix should have the following file
attributes or later:

RAS FIX:

  Date       Time     Size    File name     Platform
  --------------------------------------------------
  01/18/2000 12:47p   71,440  rastapi.dll   Alpha
  01/18/2000 12:47p   35,600  rastapi.dll   i386

RRAS FIX:

  01/25/2000 05:55p   70,928  rastapi.dll   Alpha
  01/25/2000 05:56p   35,600  rastapi.dll   i386



To work around this issue, stop and restart the RAS service.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT 4.0.

Additional query words:

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Keywords          : kbnetwork kbWinNT400PreSP7Fix 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400sp6 kbWinNTS400sp5 kbWinNTS400sp4 kbWinNTS400sp3 kbWinNTS400search
Version           : winnt:4.0 SP3,4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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