4) Troubleshooting Ethernet Networks Flashcards
A network technician is trying to troubleshoot attenuation and measure accordingly. What unit of measurement expresses attenuation?
A. dB
B. SNR
C. ms
D. Mbps
Attenuation is the loss of signal strength, measured in decibels (dB). dB expresses the ratio between two measurements, and in this case, signal strength at origin and destination.
Noise is anything transmitted within or close to the channel that is not the intended signal and expressed as the signal-to-noise ratio (SNR).
Important network performance characteristics are bandwidth, throughput, packet loss, and the speed at which the system delivers packets. Speed, measured as a unit of time, is typically milliseconds (ms).
Throughput is an average data transfer rate achieved over a period of time, excluding encoding schemes, errors, and other losses incurred at the physical and data link layers. Its unit of measurement is in Mbps or Gbps.
A network operator is trying to troubleshoot kinks and imperfections in cabling that could affect performance. What should the network operator use to test the cabling?
A. dB
B. SNR
C. ms
D. TDR
A help desk technician is troubleshooting communications between a client and print server. They are trying to perform the step to identify symptoms and duplicate the problem. Which of the following does NOT fall under this step?
A. Question the obvious
B. Physical inspection
C. Check system logs
D. Use a test system
A. Question the obvious
Questioning the obvious falls under establishing a theory of probable cause.
This step includes making a physical inspection and looking for something out of the ordinary. Sometimes the issue can be a layer 1 issue.
This step also includes checking system logs or diagnostic software for information. This can often be helpful in troubleshooting, although it does not always indicate the root of the problem.
Technicians should duplicate the problem on the user’s system or a test system. They will need to try to follow the same steps as the user.
