question about data telecommunication

Description

1. What does the data link layer do?

2. What is media access control, and why is it important?

3. Compare and contrast roll-call polling, hub polling (or token passing), and contention.

4. Describe four types of noise.

5. How do amplifiers differ from repeaters?

6. What are three ways of reducing errors and the types of noise they affect?

7. Describe three approaches to detecting errors, including how they work, the probability of detecting an error, and any other benefits or limitations.

8. Briefly describe how even parity and odd parity work.

9. Briefly describe how checksum works.

10.How does CRC work?