- Wired Network Troubleshooting 1

Question 1

Attenuation

Answer 1

Attenuation

• Loss of intensity as signal moves through a medium

Question 2

Latency

Answer 2

Latency
• A delay between the request and the response
• Waiting time
Packet captures can provide detailed analysis
• Microsecond granularity
• Get captures from both sides

Question 3

Jitter

Answer 3

• Jitter is the time between frames
• Excessive jitter can cause you to miss information,
“choppy” voice calls

Confirm available bandwidth
Make sure the infrastructure is working as expected
Apply QoS (Quality of Service)

Question 4

Crosstalk

Answer 4

Crosstalk (XT)
• Signal on one circuit affects another circuit
• In a bad way
Check your crimp
• Maintain your twists
• Test and certify your installation

Question 5

Avoiding EMI and interference

Answer 5

Cable handling
• No twisting - don’t pull or stretch
Avoid power cords, fluorescent lights,
electrical systems, and fire prevention components

Question 6

Opens and shorts

Answer 6

Opens and shorts
• A short circuit
• Two connections are touching
• Wires inside of a cable or connection
• An open circuit
• A break in the connection
Replace the cable with the short or open
• Difficult or impossible to repair
• Advanced troubleshooting with a TDR
• Time Domain Reflectometer

Question 7

Troubleshooting pin-outs

Answer 7

Troubleshooting pin-outs
• Cables can foul up a perfectly good plan
• Test your cables prior to implementation

Question 8

T568A and T568B termination

Answer 8

You can’t terminate one side of the cable with
568A and the other with 568B
• It won’t be a straight-through cable

Question 9

Incorrect cable type

Answer 9

Incorrect cable type
• Excessive physical errors, CRC errors
• Check your layer 1 first
• Confirm the cable specifications with a TDR
• Advanced cable tester can identify damaged cable

Question 10

Transceiver mismatch

Answer 10

Transceiver mismatch
• Transceivers have to match the fiber
• Single mode transceiver connects to single mode
fiber