DOCUMENT:Q117715 13-JUN-2001 [win3x] TITLE :Slow Performance over IBM Software Source Routing Bridge PRODUCT :Microsoft Windows 3.x Retail Product PROD/VER::3.11 OPER/SYS: KEYWORDS:kbfile kbgraphxlinkcritical ====================================================================== 3.11 WINDOWS kbnetwork kbprb kbfile ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows for Workgroups version 3.11 ------------------------------------------------------------------------------- SYMPTOMS ======== Data transfers across a source routing bridge are very slow or appear to hang. CAUSE ===== Windows for Workgroups (NetBEUI protocol) over a Token Ring Source Routing Bridge advertises a Largest Frame (LF) size of 8130 bytes. However, the Maxframe size is negotiated at 156 bytes. This causes very slow data transfer. A network trace illustrates the problem: Destination Source Summary Server WFWClient<00> NETB D=2B S=16 Session initialize NETB: ----- NETBIOS Session Initialize ----- NETB: NETB: Header length = 14, Data length = 0 NETB: Delimiter = EFFF (NETBIOS) NETB: Command = 19 NETB: Flags = 89 NETB: 1... .... = NO.ACK ability NETB: .... 100. = Largest frame value = 4 <<<8130 bytes -IBM Spec NETB: .... ...1 = Version 2.0 or higher NETB: Max data receive size = 156 <<< Small Frame size negotiated. NETB: Transmit correlator = 0000 NETB: Response correlator = 0016 NETB: Remote session number = 43 NETB: Local session number = 22 If the bridge advertises a size OTHER THAN 8130 bytes, this problem does not occur. WORKAROUND ========== An updated NETBEUI.386 file is available to correct this problem. Replace your existing NETBEUI.386 file with the updated version. For information about how to obtain the updated driver, refer to the More Information section below. The following options allow you to work around this problem: - Use the real-mode NetBEUI protocol. -or- - Execute "Net start Full" at the command prompt before running Windows for Workgroups. -or- - Configure the bridge by changing a Largest Frame size (smaller or larger). In a case where an IBM software bridge is used to connect two 16 MB rings, it is not possible to change the LF size on the bridge software. In this case, you can bring down the network ring to 4 MB, or install a hardware bridge. NOTE: This problem does not occur on LAN Manager/Windows workstations. MORE INFORMATION ================ The following file is available for download from the Microsoft Download Center: DownloadDownload Netbeui.exe now (http://download.microsoft.com/download/wfw311/Update/1/WFW/EN-US//Netbeui.exe) For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file. STATUS ====== Some of the products discussed here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability. Additional query words: 3.11 TR bridging client hangs freezes locks ====================================================================== Keywords : kbfile kbgraphxlinkcritical Technology : kbAudDeveloper kbWFWSearch kbWFW311 Version : :3.11 ============================================================================= 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.