Setting up the Client Computer

The next task is to set up a client computer in order to view the test streams and simulate the client load. You’ll need a computer running Microsoft Windows 98 Second Edition, Windows 2000, Windows ME, Windows XP Home Edition, Windows XP Professional, or Windows Server 2003. For optimal testing, Windows Media Player should not be running on the same computer as Windows Media Encoder or Windows Media Services.

Once your client computer is configured, you’ll need to connect it to your internal network for testing. You should also install Windows Media Load Simulator 9 Series, which is available on the Windows Media 9 Series Web site (http://www.microsoft.com/windowsmedia) or on the CD provided with this book.

As its name suggests, Windows Media Load Simulator simulates the effects of hundreds of clients connecting to and receiving unicast streams from the Windows Media server. Its purpose is to determine the maximum capacity of your server by initiating a large number of client requests for streams—enough to potentially overwhelm your site or system resources. Windows Media Load Simulator requests and streams the content, but doesn’t actually render it on the client end. This preserves CPU resources and memory on the client and enables one computer to simulate the load of a hundred or more.

The maximum number of client requests that can be simulated on a single client computer depends on the hardware configuration of that computer and the average bit rate of the simulated streams. Typically, a single client computer can simulate a few hundred concurrent client connections. Add client computers if you need to simulate additional client connections, but be sure to install Windows Media Load Simulator on each of them. Each instance of Windows Media Load Simulator would then connect to the same Windows Media server. For example, if you want to determine whether your Windows Media server can handle 1,000 client requests for unicast content, you could run Windows Media Load Simulator 9 Series on five client computers and configure each instance to simulate 200 clients. You might also want to use different network segments to avoid saturating your network during the test.

The peak usage and stress testing described above should always be done offline using a closed LAN. Because Windows Media Load Simulator creates the same server and network load that you get from an equivalent number of real clients, running a stress test over an active network could consume all available bandwidth and block real end users from gaining access to servers. By running peak usage tests over a closed LAN, you avoid disruption to end users on a network or the Internet, and you are free to run the bit rate up as high as necessary to completely test all servers and local network hardware.