Networking

Punchdown Tools

If you have ever looked in a network closet, you have probably seen a distribution block, more commonly called a patch panel. A patch panel is a freestanding or wall-mounted unit with a number of port connections on the front. In a way, it looks like a wall-mounted hub without the light-emitting diodes (LEDs). The patch panel provides a connection point between network equipment such as hubs and switches and the ports to which PCs are connected, which are normally distributed throughout a building.

Behind each of the individual RJ-45 jacks on the patch panel are connectors to which are attached the eight wires from a piece of twisted-pair cable. These wires are commonly attached to the patch panel by using a tool called a punchdown tool. To use the punchdown tool, you place the wires from the cable into the appropriate slots in the back of the patch panel, and then use the tool push the wires firmly down into the slots. The insulation is stripped, and the wire becomes firmly embedded into the connector. Because the connector strips the insulation on the wire, it is known rather grandiosely as an insulation displacement connector (IDC).

Tone Generators (and Tone Locators)

A tone generator is a device that can save a network installer many hours of frustration. Strangely, the tone generator has a partner that goes wherever it goes but is seldom mentioned: the tone locator. You might hear the tone generator and the tone locator referred to as the fox and hound.

As you might expect, the purpose of the tone generator is to generate a signal that is transmitted on the wire you are attempting to locate. At the other end, you press the tone locator against individual wires. When it makes contact with the wire that has the signal on it, the locator emits an audible signal or tone.

The tone locator is a useful device, but it does have some drawbacks. First, it often takes two people to operateone at each end of the cable. Of course, one person could just keep running back and forth; but if the cable is run over great distances, this could be a problem. Second, using the tone generator is a time-consuming process because it must be attached to each cable independently.