DOCUMENT:Q162626 12-JUN-2001 [sna] TITLE :RUI_READ Stops When Processing Buffers Larger Than 3 KB PRODUCT :Microsoft SNA Server PROD/VER:WINDOWS:2.0,2.1,2.11,2.11 SP1,3.0 OPER/SYS: KEYWORDS:kbnetworkkbbuglist ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft SNA Server, versions 2.0, 2.1, 2.11, 2.11 SP1, 3.0 ------------------------------------------------------------------------------- SYMPTOMS ======== An RUI_READ (immediate) will stop when an RU size is greater than 3 KB. No errors are generated; however, the application does not respond. CAUSE ===== When an application has issued an RUI_BID verb, the WINRUI32 library will post the verb as soon as 12 or more bytes of RU data are available to return to the application. Normally, due to the nature of the message- passing mechanism between SNA Server and the RUI library, this means that the complete RU has been received by the RUI library, and when the application issues a subsequent RUI_READ(immediate), the RUI_READ will complete successfully. However, when the RU size on the session exceeds a certain size (just over 3 KB), SNA Server will split the messages it sends to the RUI library into smaller blocks. The RUI library, however, continues to complete the RUI_BID when it receives the first block of a new RU. If the application issues an RUI_READ(immediate) before the remainder of the RU arrives, the RUI_READ will complete with a return code of UNSUCCESSFUL. This will confuse any application that (rightly) expects all the data to be available when the RUI_BID is posted. RESOLUTION ========== A fix to the RUI library has been created to prevent it from posting an RUI_BID until all the blocks of a large RU have been received. Updated files: Windows NT: \System\Winrui32.dll Windows 95: \System\Winrui32.dll Windows 3.x: \System\Winrui.dll OS/2: \System\Rui.dll MS-DOS: \Dosacs.lib (application must be relinked) STATUS ====== Microsoft has confirmed this to be a problem in SNA Server versions 2.0, 2.1, 2.11, 2.11 Service Pack 1, and 3.0. This problem was corrected in the latest SNA Server for Windows NT, 2.11 and 3.0 U.S. Service Packs. For information on obtaining these service packs, query on the following word in the Microsoft Knowledge Base (without the spaces): S E R V P A C K Additional query words: prodsna ====================================================================== Keywords : kbnetwork kbbuglist Technology : kbAudDeveloper kbSNAServSearch kbSNAServ300 kbSNAServ200 kbSNAServ211 kbSNAServ210 kbSNAServ211SP1 Version : WINDOWS:2.0,2.1,2.11,2.11 SP1,3.0 ============================================================================= 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 2001.