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Windows 7 - increase the limit of concurrent tcp connections (not related to EULA file sharing limits) RRS feed

  • Question

  • I have an application that tries to open as many http requests as possible (in order to stress test a proxy implementation) It seems to me that Win7 (SP1) may have a limitation on number of concurrent opened connection (it may be the so called half-open state if I'm not wrong). Is there something I can do for client ? and also I test using a vista PC that acts as a proxy server. It would be great if I could configure it to sustain at least 50 new connections initiated / second on client side and many more on server. I made the modification according with http://technet.microsoft.com/en-us/magazine/2007.12.network.aspx by setting TcpNumConnections = 150 but it doesn't make a difference. I still only see about 20 tcp sockets associated with my http client by using tcpviewI 
    • Edited by raiderG Friday, December 2, 2011 6:22 PM
    Friday, December 2, 2011 6:13 PM

Answers

  • Hi,

     

    According your description I suggest that you could try to disable the half-open TCP connections limit, set the value of the EnableConnectionRateLimiting DWORD registry entry to 0 (0x00000000). To do this, follow these steps:

    1.       Click Start, type regedit in the Start Search box, and then click regedit.exe in the Programs list. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.

    2.       Locate and then double-click the following registry key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\EnableConnectionRateLimiting

    3.       In the Value data box, type 0, and then click OK.

    4.       Exit Registry Editor.

    5.       Restart the computer.

     

    Hope that helps


    William Tan

    TechNet Community Support

    Thursday, December 8, 2011 9:26 AM
  •  

    http://www.windows7hacker.com/index.php/2011/01/how-many-concurrent-connections-allowed-to-access-a-windows-7-computer/

    Prior to Windows 7, any Windows desktop version of operating system limited you to only allow up to 10 concurrent connections maximum, or only 5 in Vista Home Basic edition. Has this changed in Windows 7? Sure it does. With Windows 7, all editions support 20 concurrent connections for services such as File Services, Print Services, IIS, Internet Connection Sharing, and Telephony.

    Thursday, December 8, 2011 5:52 PM

All replies

  • Hi,

     

    According your description I suggest that you could try to disable the half-open TCP connections limit, set the value of the EnableConnectionRateLimiting DWORD registry entry to 0 (0x00000000). To do this, follow these steps:

    1.       Click Start, type regedit in the Start Search box, and then click regedit.exe in the Programs list. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.

    2.       Locate and then double-click the following registry key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\EnableConnectionRateLimiting

    3.       In the Value data box, type 0, and then click OK.

    4.       Exit Registry Editor.

    5.       Restart the computer.

     

    Hope that helps


    William Tan

    TechNet Community Support

    Thursday, December 8, 2011 9:26 AM
  •  

    http://www.windows7hacker.com/index.php/2011/01/how-many-concurrent-connections-allowed-to-access-a-windows-7-computer/

    Prior to Windows 7, any Windows desktop version of operating system limited you to only allow up to 10 concurrent connections maximum, or only 5 in Vista Home Basic edition. Has this changed in Windows 7? Sure it does. With Windows 7, all editions support 20 concurrent connections for services such as File Services, Print Services, IIS, Internet Connection Sharing, and Telephony.

    Thursday, December 8, 2011 5:52 PM
  • Hi there

    I have looked at few windows 7 pro pc to find the entry  EnableConnectionRateLimiting

    under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

    buy it is not exist can you please let me know if this entry is located elsewhere

    cheers

    Monday, May 9, 2016 3:12 PM
  • Hi there

    I have looked at few windows 7 pro pc to find the entry  EnableConnectionRateLimiting

    under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

    buy it is not exist can you please let me know if this entry is located elsewhere

    cheers, pls replay.


    Ashok Kumar.s

    Thursday, June 23, 2016 4:52 AM
  • Ashok I were using windows 10 and didn't find this entry as well. I think you have to add this entry manually. check the Link http://www.technorms.com/24822/disable-max-limit-set-simultaneous-network-connections

    My problem is similar. I had WCF application which Looks like processing  about 200 odd simulataneous request at max. So i ported it to self hosted service where I am sure no IIS limit will restrict. But still can't get any advantage.

    So now i am also looking for any system level restriction of tcp concurrent connection.


    Kamran Shahid Application Developer (MCP,MCAD,MCSD.NET,MCTS,MCPD.net[web])

    Wednesday, June 29, 2016 5:07 PM