DOCUMENT:Q127144 08-AUG-2001 [winnt] TITLE :Windows NT WinSock Listen (Backlog) Parameter Limit PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.5,3.51,4.0 OPER/SYS: KEYWORDS:kbnetwork kbAPI kbSDKPlatform kbWinsock kbGrpDSNet ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 ------------------------------------------------------------------------------- The WinSock listen() call backlog parameter under Windows NT version 3.5 and 3.51 accepts a maximum value of 100. The maximum backlog parameter is 5 on Windows NT 4.0 Workstation, and 200 on Windows NT 4.0 Server. WinSock server applications use the listen() call to establish a socket for listening for incoming connections. This calls second parameter, backlog, is defined as the maximum length to which the queue of pending connections may grow. The WinSock version 1.1 specification states the maximum value for the backlog parameter is 5. However, Windows NT version 3.5 accepts up to 100 for this value. Services that handle a large number of socket connections may be written to use a larger backlog value to prevent client connection requests from being dropped. This can be useful when writing applications such as World Wide WEB (WWW) and gopher servers. Additional query words: prodnt ====================================================================== Keywords : kbnetwork kbAPI kbSDKPlatform kbWinsock kbGrpDSNet Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search Version : winnt:3.5,3.51,4.0 ============================================================================= 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.