Spring 2021 CSE30264 Homework 3


Total Points: 60 points
Scope: Chapters 3
Due: April 16 (Friday), 2021 by the end of day (11:59 pm Eastern)
Grouping: To be completed individually

Problems

Problem 1: [10 points] What is the MAC protocol of Ethernet and describe how it works using your own words. Does Wireless MAC protocol use "collision detection"? If yes, explain why. If not, explain why not.

Problem 2: [10 points] What is a hidden terminal problem? How is the hidden terminal problem addressed in 802.11 networks?

Problem 3: [24 points, 4 points for each sub-question] Using the example network below, give the virtual circuit table for all the switches after each of the following connections is established. Assume that the sequence of connections is cumulative; that is, the first connection is still up when the second connection is established, and so on. Also, assume that the VCI assignment always picks the lowest unused VCI on each link, starting with 0, and that VCI is consumed for both directions of a virtual circuit.
  1. Host F connects to host G

  2. Host D connects to host E

  3. Host A connects to host I

  4. Host F connects to host B

  5. Host J connects to host C

  6. Host G connects to host D



Problem 4: [16 points, 4 points for each switch's forwarding table] Consider the arrangement of learning bridges shown in the following figure. Assuming all are initially empty, give the forwarding tables for each of the bridges B1-B4 after the following transmissions: (Note: You only need to show the final forwarding tables after all three transmissions: A->C, C->A, D->C).

Submission Instructions

Create a PDF file containing your answers. Place your name at the beginning of the file. Copy the file into /escnfs/courses/sp21-cse-30264.01/dropbox/yournetid/hw3/hw3.pdf.