Testing Network Throughput

If your network works but works slowly, you may have a problem with your network cabling or hubs. First of all, if you are using 10/100Mbps Ethernet adapters, you'll only get full speed if you your network hub is also 100Mbps capable. If you are using a 10Mbps hub, your network will run at the slower speed. In this case, if you can't live with it, you'll have to update your hub to a 100Mbps or 10/100 dual-speed unit.

If that's not the problem you can diagnose slow network throughput with the Windows Performance monitor tool. The Performance Monitor can display utilization statistics collected from your network card and its drivers. You must first install the Network Monitor Driver to enable the collection of network driver performance statistics. Do this on the most-used computer on your network:

1.	In Network Connections, open Local Area Connections, and select Properties.
2.	Select Install, choose Protocol, click Add, and select the Network Monitor Driver.
3.	Click OK to close the Properties dialog.

Now run the Performance Monitor by choosing Start, All Programs, Administrative Tools, Performance. You can use the Performance Monitor to measure network utilization and other network statistics.

(If Administrative Tools doesn't appear, right-click the Start button and select Properties. Click Customize and view the Advanced tab. Find System Administrative Tools in the Start Menu Items list and check Display on the All Programs Menu. Then run the Performance Monitor as described above.)

Measuring Network Utilization

In the right pane of the Performance console, you can add an item to the graph of performance statistics like this:

1.	Right-click in the graph pane, and select Add Counters.
2.	Check Use Local Computer Counters.
3.	Select the performance object named Network Interface.
4.	Select a counter such as Bytes Received/Sec, Packets Received Errors, and so on.
5.	Check Select Instances from List, highlight your LAN adapter interface name and click Add.
6.	Select Close.

The Performance Monitor then graphs the amount of data traffic on your network connection or connections and the plot is updated as you watch. Now you can visually monitor the traffic on your network.

To learn more details about this nifty system-monitoring application, p. 946.

NOTE

To learn more information about network design and maintenance, take a look at Upgrading and Repairing Networks, Fourth Edition, from Que.

To remove counters from the Performance graph, you can select the items in the legend below the graph and click the X icon at the top of the graph. Alternatively, you can right-click the graph and select Properties; next, select the Data tab, select Counters, and then click Remove.