CompTIA Network+ (N10-007) — Question 175

A telecommunications provider has just deployed a new OC-12 circuit at a customer site. While the circuit showed no errors from the provider end to the customer's demarcation point, a network administrator is trying to determine the cause of dropped packets and errors on the circuit. Which of the following should the network administrator do to rule out any problems at Layer 1? (Choose two.)

Answer options

• A. Use a loopback at the demark and router, and check for a link light
• B. Use an OTDR to validate the cable integrity
• C. Use a pinout tester to validate the cable integrity
• D. Use a multimeter to validate the cable integrity
• E. Check for any devices that may be causing EMI on the cable
• F. Clean the cables to be sure they are free of dust and debris

Correct answer: A, B

Explanation

Using a loopback at the demarcation point and router helps verify that the circuit is functioning correctly at Layer 1 by checking for signal transmission. An OTDR is useful for testing the cable integrity, ensuring that the physical medium is not causing issues. The other options may help diagnose problems but do not directly test Layer 1 connectivity as effectively as A and B.