Windows 95 Multiple Provider Router and Network Call Order (155857)

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The Multiple Provider Router (MPR) routes incoming network requests to the appropriate network provider. It uses the same interface whether one or multiple network providers is installed. It also allows for unlimited protected-mode network providers as well as one 16-bit network provider.

When multiple network providers are installed, MPR passes the call to each installed network provider one at a time, in a defined order. The installed network providers are sorted by this defined order when they are loaded. Providers with lower values are called before those with higher values. Once a network provider returns a successful resolution of a call, additional network providers are not tried.

The only method to change the order in which installed network providers are called is to modify the Windows 95 registry.

NOTE: For information about how to edit the registry, view the Changing Keys And Values online Help topic in Registry Editor (Regedit.exe). Note that you should make a backup copy of the registry files (System.dat and User.dat) before you edit the registry.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows 95. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

Network provider information is stored in the following registry branch:

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
				

Under the Services branch, there is a CallOrder key for each installed network provider. The default CallOrder value for the Novell NetWare network provider is 00 00 00 20; the default value for the Microsoft network provider is 00 00 00 40. In this scenario, the NetWare network provider is called before the Microsoft network provider because of its lower CallOrder value. The selection of the primary client does not affect these settings.

Mpr.dll uses two other components, Mprserv.dll and Mprexe.exe, to facilitate faster loading of network providers and routing of network requests. Programs link to Mpr.dll (the smaller component), which copies API parameters to shared memory and signals a thread in Mprexe.exe to do the work. Mprserv.dll has the code to load net providers, route requests, and so on.