Checking Your Throughput

The rate that data passes over any network, wireless or wired, can vary greatly depending on several factors. There's overhead: the chatter between computers to prepare for and confirm the data transfer. Then you have the distance over which the data travels . As you know, the farther you are from your access point, or another wireless network adapter, the slower your data transfer will be.

You can check the rate of data transfer by downloading a handy, free program called Qcheck and then installing it on (at least) two machines that you want to test. You install the program and launch it on one machine, then run the program on another machine. Using a simple, friendly interface, you click a button to send sample data packets over your network, which Qcheck times to see how fast your network is communicating.

You might be surprised that your wireless network is sending data at less than half, sometimes much less than half, its maximum speed. In my home, my 11 mbps 802.11b network tends to send data no faster than 5 mbps. My 802.11a network (with a maximum possible data rate of 54 mbps) sends data at about 22 mbps. These are the speeds I see in ad-hoc mode. In infrastructure mode (using an access point), they are about half these speeds. In most cases, it makes little difference, since your cable or DSL modem likely transfers data at a maximum of 1.5 mbps. The slowdown hurts the most when transferring files from one networked computer to another.

To use Qcheck, follow these simple steps:

1. Download the program from www. netiq .com.

2. Install the program on one computer on your network (Figure 10.18).

   Figure 10.18. Installing Qcheck.

   

3. Install the program on at least one other computer on your network.

4. Launch the program on both your computers (it needs to be running on at least two computers).

5. Click the Throughput button to start the speed test (Figure 10.19).

   Figure 10.19. Click the Throughput button.

   

Qcheck sends data packets between the two computers and records the time it takes for the packets to transfer. Click the Throughput button several times to run at least three tests. Running multiple tests and averaging the results should provide you with a reliable idea of the speed at which the data is transferred over your wireless network.