Basic Cable Testing 7
Troubleshooting Basics
Troubleshooting Basics
Troubleshooting LAN cable installations is most often required during cable installation or modification. When cable is handled carefully and installed correctly, it usually operates
Finding Cable Faults
A general rule for finding cable faults is as follows: With very few exceptions, faults occur at cable connections. Cable connections include telecommunication outlets, patch panels, punchdown blocks, and transition connectors.
Connections are the most likely places for faults for at least three reasons: (1) Connections always alter the impedance of the transmission path, (2) connections are likely places for faults caused by wiring errors and faulty or incompatible hardware installation, and (3) connections always cause some crosstalk due to the untwisting of cable pairs.
When cable is handled carelessly, faults can occur in the middle of the cable. These faults can happen when the cable is stepped on, sharply bent, pinched by cable ties or other hardware, or otherwise stressed.
A general procedure for finding cable faults (excluding sources of noise and traffic faults) involves the following steps:
1.Run an Autotest on the cable.
2.Analyze the results of failed tests and determine a probable cause for the failure. If you are using Model
3.If the Autotest results do not indicate the location of the fault, run an additional test (such as TDR or TDX analyzer) that will help you locate the fault. Model
4.Visually inspect the cable at the location indicated by the tests.
5.Repair the fault and retest the cable.
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