Learning Objectives

After successfully completing this section, you should be able to

  1. describe broadcast and multicast.
  2. explain how routing is done for broadcast and multicast, respectively.
  3. explain how some broadcast and multicast algorithms and protocols work.

Learning Tasks

Required:

  1. Watch the slideshow for this section.
  2. Study the following sections in the textbook:

4.4: Generalized Forwarding and SDN
4.5: Middleboxes

Terms and Topics

Section 4 – Generalized Forwarding, SDN and Middleboxes

Generalized forwarding
Match-plus-action paradigm
Match-plus-action table
OpenFlow
Flow table in OpenFlow
Ingress port

Middleboxes
Services of middleboxes
Network function virtualization
Architectural Principles of the Internet
The IP hourglass 

Leading Questions

  1. What is generalized forwarding? How is it done?
  2. What role does a match-plus-action table play?
  3. What can be matched in generalized forwarding?
  4. What can be the actions in a match-plus-action table?
  5. When should a matched packet be dropped?
  6. What packet-header fields can be modified before a packet is forwarded to the chosen output port? Why?
  7. Why are routers considered the workhorses of the network layer?
  8. Which network devices are called middleboxes in a network? What roles do each of them play?
  9. What services are performed by network middleboxes?
  10. What is network function virtualization?
  11. What are the three architectural principles of the Internet?
  12. Why is the Internet protocol stack illustrated as a narrow waist?