Err Msg: "Unable to Connect to <Web site>" Over SSL Connection

• Microsoft Internet Information Server version 3.0

SYMPTOMS

On a Web site with a large number of concurrent users using Secure Sockets Layer (SSL), the client may randomly receive the following error message:

Unable to connect to '<Web site>' a connection with the server could
not be established.

CAUSE

The more complex the page, the longer it takes to download the page; therefore, the fewer people who can enter the site at one time. If you have a site with complex pages, you will encounter this problem with only a small number of concurrent users more frequently than will a site with simpler pages.

This problem arises because each individual object on a page creates a separate session to download this object to the client. By default, the SSL component has only sufficient cache to maintain 100 sessions. This limitation is associated with the schannel component (Schannel.dll), used for SSL/PCT.

WORKAROUND

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

To increase the size of the SSL server cache, modify the following registry entry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL

Value Name: ServerCache
Data Type: REG_DWORD
Data: 1000 (Default = 100)

Keywords :
Version : WINNT: 3.0
Platform : winnt
Issue type : kbprb