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 ====================================================================== ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- 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: ====================================================================== 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 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.