Learning Objectives

After successfully completing this section, you should be able to

  1. describe link layer services.
  2. discuss the general issues related to the services provided by the link layer.
  3. explain the link layer’s relationships with the layers above and below it in the Internet protocol stack.

Learning Tasks

Required:

  1. Watch the slideshow for this section.
  2. Study Section 6.1, Introduction to the Link Layer, in the textbook.

Terms and Topics

Section 1 – Introduction to the Link Layer

Nodes in the link layer
Links in the link layer
Link layer frame
Link layer services
Framing
Link access

Reliable delivery
Error detection and correction
Where is the link layer implemented?
Network adapter
Network interface card (NIC)

Leading Questions

  1. What services does the link layer provide?
  2. What does a data link layer protocol do?
  3. What are frames?
  4. What are some commonly used link layer protocols?
  5. What are nodes and links, respectively, in a link layer?
  6. What are the framing, link access, reliable delivery, and error detection and correction services provided by a link layer?
  7. Where is the link layer implemented in a network?
  8. What do network interface cards (NICs) do in computer networks?