Troubleshooting copper wire networks.

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Instructor, PACE-IT Program – Edmonds Community College

Areas of Expertise Industry Certifications

PC Hardware

Network Administration

IT Project Management

Network Design

User Training

IT Troubleshooting

Qualifications Summary

Education

M.B.A., IT Management, Western Governor’s University

B.S., IT Security, Western Governor’s University

Entrepreneur, executive leader, and proven manger with 10+ years of experience turning complex issues into efficient and effective solutions.

Strengths include developing and mentoring diverse workforces, improving processes, analyzing business needs and creating the solutions required— with a focus on technology.

Brian K. Ferrill, M.B.A.

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Troubleshooting copper wire networks I.

– Summary of troubleshooting methodology.

– Common copper wire problems.

PACE-IT.

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Summary of troubleshooting methodology.Troubleshooting copper wire networks I.

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Summary of troubleshooting methodology.

Seven-step troubleshooting methodology.

1) Identify the problem.» A mistake in identifying the problem can negate the rest of the

steps!» Remember, the problem is not the symptom; the problem is what

is causing the symptom to occur.

2) Establish a theory of probable cause.

3) Test the theory of probable cause.

4) Establish a plan of action to resolve the problem.

5) Implement the solution, or escalate as necessary.

6) Verify full system functionality.

7) Document findings, actions, and outcomes.

Troubleshooting copper wire networks I.

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Common copper wire problems.Troubleshooting copper wire networks I.

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Common copper wire problems.

– Electromagnetic interference (EMI)/radio frequency interference (RFI).

» Because copper wire transmissions are electrical in nature, their electrical signals can be degraded by sources of EMI and RFI.

• Sources of EMI/RFI may corrupt the network signal, leading to loss of communication or poor communication between end nodes.

» Sources of EMI/RFI include:• Other electrical wires; network cables should be kept

separate from normal electrical runs and, if possible, network cabling should cross electrical wires at a 90⁰ angle.

• Other electrical components may inject EMI and RFI into the environment; manufacturing environments often have a lot of EMI and RFI present.

• One major source of EMI/RFI is fluorescent lights.» EMI/RFI problems can often be identified by when they

occur; for instance, does the problem only happen when somebody turns on all the lights?

• The solution may be to move from UTP to STP or to re-route the network cable to avoid the source of the EMI/RFI.

Troubleshooting copper wire networks I.

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Common copper wire problems.

– Distance limitations.» All network transmission media experience attenuation

—loss of signal strength over distance—which can lead to poor communication or loss of communication between end nodes.

• A decibel (dB) logarithmic scale is used to measure the amount of acceptable and unacceptable attenuation.

• As network transmission speeds increase, the attenuation also increases—as a ratio of signal-to-signal loss.

» Possible attenuation issues can be identified when a cable cannot handle the higher transmission speeds for which it is rated.

» A cable certifier or time-domain reflectometer (TDR) will usually identify this problem.

• Possible solutions are to install a network switch to boost the signal strength, or to re-route the network run to create a shorter run of cable.

Troubleshooting copper wire networks I.

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Common copper wire problems.

– Crosstalk.» Even with the steps taken to reduce it, all cables

experience crosstalk between the pairs, which can lead to intermittent or constant transmission issues.

• More crosstalk is present at the near end (where the transmission originates) than at the far end (where the transmission is received).

• As network transmission speeds increase, the opportunity for crosstalk increases.

» A good cable certifier or TDR will identify the problem.• Possible solutions include replacing the network run

with cable rated for a higher transmission speed, replacing the cable with one that has better shielding, or reducing the transmission rate of the network.

Troubleshooting copper wire networks I.

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Common copper wire problems.

– Bad connectors.» Once a good cable is in use, the end connectors may

still become broken—especially after repeated use, leading to a loss in connectivity.

• The locking tabs on an RJ45 can be easily broken, leading to a loose connection—creating an open connection.

» A cable tester may identify this problem as an open connection, a thorough inspection of the cable ends can help to identify the problem.

• The solution is to replace the bad connector with a good one.

– Bad cable.» Cables can go bad—especially if they are in places

susceptible to damage—leading to loss in connectivity or poor network communication.

» A cable tester can be used to identify the problem as either an open connection or a short.

• An open connection indicates a broken wire.• A short indicates an electrical signal is traveling down

an unintended path—down the wrong wire.• The solution is to replace the bad network cable.

Troubleshooting copper wire networks I.

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What was covered.Troubleshooting copper wire networks I.

A seven-step troubleshooting methodology involves: identifying the problem, establishing a theory of probable cause, testing the theory of probable cause, establishing a plan of action to resolve the problem, implementing the solution or escalating, verifying full system functionality, and documenting findings, actions, and outcomes. Misidentifying the problem can negate the rest of the troubleshooting steps.

Topic

Summary of troubleshooting methodology.

Summary

Possible copper wire network problems include: EMI/RFI, cables exceeding their distance limitations, too much crosstalk, bad connectors, and bad cabling.

Common copper wire problems.

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THANK YOU!

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