By default, Windows can handle a maximum of 5000 open TCP connections. If your loads are higher, you may experience problems such as failed requests for new connections and poor performance.
The following steps are designed to improve Windows’ ability to handle the connections by making changes to the registry.
Important: Changes to the registry can cause serious problems, including inability to reboot your machine. You may want to make a backup of the registry before continuing. For information on backing up the registry, visit support.microsoft.com and type in "registry editor" into the Search box. Instructions for working with the registry editor vary depending on your Windows version.
Step 1: Start the Registry.
From the Windows Start menu:
- If you are using Windows XP: from the Windows Start menu click Run.
- If you are using Windows 7: type "Run" and press Enter (Windows 7).
From the Run dialog, type "regedit" and click OK.
Step 2: Locate HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services in the Registry Editor.
From this location:
- For IPv4: go to Tcpip.
- For IPv6: go to Tcpip6.
Step 3: Select the registry subkey Parameters.
After you select the registry subkey parameters, check the right panel for the registry entries MaxUserPort and TcpTimedWaitDelay. If these entries do not exist, create them as described in Step 4.
Step 4: Create registry entries:
- Right-click on Parameters, and from the shortcut menu select New and then select DWORD (32-bit) Value.
On the right side of the Registry Editor, you will see that a new registry entry, New Value #1, is automatically created. Change the names of the new entries as described in Step 3.
To edit the values of these entries:
- Select the entry and press Enter, or right-click on the entry and select Modify. The Edit DWORD Value dialog opens.
- Change the Value setting for MaxUserPort to 65534, and the Value setting for TcpTimedWaitDelay to 30.