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However, these devices, apart from costing several times as much as a standard power meter and light source combination ($4,000 or more, in some cases), do not compare the test results to a baseline established with that equipment. Instead, they compare them to preprogrammed standards, which, when it comes to fiber-optic cables, can be defined as somewhat loose. The result is a device that is designed for use primarily by people who really don’t understand what they are testing and who will trust the device’s pass or fail judgment without question, even when the standards used to gauge the test results are loose enough to permit faulty installations to receive a pass rating.

This is not to say that these multifunction devices are completely useless. In fact, they can be an extremely efficient means of testing and troubleshooting your network. The important thing to understand is what they are testing and to either examine the raw data gathered by the unit or verify that the standards used to formulate the pass/fail results are valid. The prices of these products can be shocking, however. The cost of both copper and fiber-optic units can easily run up to several thousand dollars, with top-of-the-line models exceeding $5,000.

Punchdown Tool

Most networks today are built using twisted-pair cable of some sort. This cable is usually terminated in wiring closets using a tool known as a punch-down tool. It is called that because, essentially, the tool punches down the wire into some kind of insulation displacement connector (IDC). IDCs make contact by cutting through, or displacing, the insulation around a single conductor inside a twisted-pair cable. The punchdown tool pushes a conductor

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