DOCUMENT:Q175903 09-AUG-2001 [crossnet] TITLE :ARI Bit Mismatch PRODUCT :Windows for Workgroups and Windows NT Networking Issues PROD/VER:WINDOWS:3.11,95; winnt:3.0,3.5,3.51,4.0 OPER/SYS: KEYWORDS:kbinterop ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 3.1 - Microsoft Windows NT Workstation version 3.1 - Microsoft Windows NT Advanced Server, version 3.1 - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 - Microsoft LAN Manager, version 2.2c - Microsoft Windows for Workgroups version 3.11 - Microsoft Windows 95 - Microsoft Network Client for MS-DOS version 3.0 ------------------------------------------------------------------------------- SUMMARY ======= If you see in a network trace an error "ARI bits mismatch", you will also see retransmissions of frames issued by higher level protocols like TCP/IP. In this case, network bandwidth is wasted on retransmissions. The above error will only be seen on a Token Ring network. CAUSE ===== The problem described above is caused by your hardware. The following are probable causes of your problem: - Insufficient receive buffers on your Token Ring network adapter card. - Slow data transfer rates to the PC bus. - Available memory in your system (RAM). Usually the first item listed is the problem, but the second and third should be considered also. MORE INFORMATION ================ The Address Recognized Indicator (ARI) bits mismatch error indicates frames that have the ARI bit set, but the Frame Copied Indicator (FCI) bit is not set. The ARI bit is set by a ring station when it detects a frame addressed to it, but has insufficient buffer to copy the frame because of congestion in the ring station's Frame Copy pipeline. The following 3 items make up the Frame Copy pipeline: - On-Board receive buffers on the network adapter. The more on-board receive buffers an adapter has, the more frames can be buffered and congestion errors are less likely to occur. Check your Token Ring adapter's specifications and determine the amount of on-board memory available for frame buffering. - Data bus transfer rate. How quickly data can be moved from the network adapter to host memory depends on the bus interface of your adapter. To keep up with incoming frame traffic, your network adapter should always fit your personal computer's bus architecture. Using a 16-bit or 32-bit bus and adapter is highly recommended for devices that must handle a large number of incoming frames. Another factor in moving data between card and the host memory is how the data is copied into memory. The two basic methods are DMA and shared memory. In general, shared memory is preferred. - Host receive buffers (RAM). The amount of buffer available in a host affect how quickly data is moved off the adapter. Insufficient buffer in the host can cause a backlog in the adapter's on-board buffer. RESOLUTION ========== To resolve this problem, perform the following steps: 1. Increase the onboard receive buffers of your Token Ring network adapter card. 2. Use a different network adapter card (with more onboard memory that fits your bus architecture). 3. Increase the physical memory of your host. Additional query words: ====================================================================== Keywords : kbinterop Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTW310 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS351search kbWinNTS350search kbWinNTS310search kbAudDeveloper kbWin95search kbWinNT310Search kbWinNTW310Search kbZNotKeyword kbLanManSearch kbWFWSearch kbZNotKeyword3 kbNetworkClientSearch kbWFW311 kbLanMan220c kbNetworkClient300DOS Version : WINDOWS:3.11,95; winnt:3.0,3.5,3.51,4.0 Hardware : ALPHA x86 Issue type : kbprb ============================================================================= 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.