Main Page

CSE 473 wiki (INTRODUCTION TO COMPUTER NETWORKS)

Links

• Piazza course page: Please use it for all Q&A related to the class. (Note: You need to sign-up before being able to access the site).
• Blackboard Site: Used only for posting grades.

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Announcements

• [12/5/2014] Office hours for the next two weeks: I will be travelling on both Monday 12/08 and Monday 12/15, and will therefore not be able to hold office hours on either day. I will have office hours on Wednesday 12/10, and will try to find another slot to replace the Monday office hours.
• [12/4/2014] Scope of final exam: As mentioned today in our last class, the scope of the final exam includes everything after the midterm exam, i.e., only topics that were not part of the midterm's scope are included.
• [12/4/14] Solution for final review problems: has been posted in the Exams & quizzes section of the wiki.
• [12/4/14] Quiz 6: Grades for quiz 6 have been posted on Blackboard. Mean grade was 5.51 with a min of 1 and a max of 10.
• [12/3/2014] Updated Lecture 17 Slides: I have uploaded an updated version of the slides that includes a modified version of the solution of the exercise on slide 29 for the case with RTS/CTS. The new version captures more accurately the effect of RTS and CTS messages, including for nodes that may not hear the RTS messages (the earlier version assumed all nodes heard all RTS and CTS messages). A slide with a time diagram was also added to illustrate the behavior. The difference with the earlier version is small because the transmission times of RTS (and CTS) messages is itself small.
• [11/28/2014] Final review: A set of problems that we will cover during the Final Review session on Thursday December 4, 2014, has been posted in the Exams & quizzes section of the wiki. In order for the review session to be useful, you should solve all the problems ahead of time. Your ability to solve them correctly and quickly will be your best indicator of weakness areas that you should focus on to do well in the final exam. Other material that can help you prepare for the exam includes past quizzes, review questions, and the exercises in the slides. The scope of the final exam spans everything that was not included in the midterm exam. As the midterm, the final will be open-book and you are allowed your computer to facilitate searching through material, though as pointed out before, spending too much time searching for answers in your notes may preclude you from completing all the final's problems.

Old Announcements

Overview

This course provides a broad introduction to computer networking.
It addresses all four major architectural layers of modern computer networks (application layer, transport layer, network layer and link layer), as well as selected topics from multimedia networking, wireless networking and network security.
Application layer topics include basic network programming and application layer protocols, including the protocols that underlie the world-wide web, electronic mail, the domain name system and peer-to-peer applications.
Transport layer topics include the User Datagram Protocol (UDP), principles of reliable data transfer and the Transmission Control Protocol (TCP), as well as peer-to-peer protocols.
Network layer topics include key protocols from the Internet protocol suite (IPv4 and IPv6, as well as ICMP, DHCP and NAT), plus router data and control plane functions. The latter covers general network routing algorithms and specific Internet unicast and multicast routing protocols (OSPF, IS-IS, PIM and BGP).
Link layer topics include multi-access protocols, Collision-Sense Multiple Access with Collision Detection (CSMA/CD), Ethernet, link layer switching, and Virtual Local Area Networks (VLAN). Wireless topics include WiFi, cellular wireless networks and mobile IP.
The topic of network security includes an introduction to basic cryptographic techniques, introduces security protocols, and offers a review of major (network) attacks and associated defense.

Prerequisite: CSE 241
Credits: 3 units.

Textbook(s)

Kurose & Ross, Computer Networking: A Top-Down Approach, 6/e (2013), 0132856204, ISBN-13: 9780132856201

See also TCP/IP Sockets in Java by K.L. Calvert and M.J. Donahoo

Logistics

• Class times and location: Tuesday & Thursday, 2:30-4:00pm in Lopata 101.
  • First class is on Tuesday August26, 2014, and last class is on Thursday December 4, 2014.
• Class grading: Review questions 10%; Quizzes 20%; Labs 25%; Midterm 20%; Final 25%
• Instructor: Roch Guerin, Bryan 509D, email: guerin@wustl.edu
  • Office hours: Monday 4:00-5:30pm & Wednesday 4:00-5:30pm
• TAs and office + studio hours (all studios and TAs office hours will be held in Urbauer 216)
  • Adam Drescher (adrescher@wustl.edu), office hours: Sunday 5-7pm & Monday 6-7pm
  • Junjie Liu (junjie.liu@wustl.edu), office hours: Sunday 3-5pm & Monday 4-5pm
  • Dana Rubenstein (dana.rubenstein@wustl.edu), office hours: Monday 5-6pm
  • Jeremy Tang (jntang@go.wustl.edu), office hours: Monday 7-8pm
  • Studio hours (Dana Rubenstein & Jeremy Tang): Wednesday 5:30-7:00pm & Friday 10:00-11:30am

• Late policy: Labs and review questions are expected to be turned in at the start of class on their due date. There will be no exception and no partial credit. On an exceptional basis, if you are unable to make it to class, you can turn in an assignment in the CSE department office (Bryan 509). Give your assignment to one of the department staff, and ask them to sign and timestamp it. The timestamp must precede the start time of the class.

• Asking questions: You can obviously ask face-to-face questions during any of the office or studio hours, but the other and possibly better means to get your questions answered is to use the Piazza site setup for the course (you will need to register to be able to access it). The TAs and I will monitor the site and do our best to answer questions in a timely manner. Posting questions on Piazza has the advantage that questions and answers are available to all students, and it is often the case that if you have a question, other students have a similar one. Because of that, neither the TAs nor I will respond to email questions. So please use the Piazza site as much as you can and don't hesitate to ask as many questions as you need to; there is no such thing as a dumb question.

• Midterm exam^*: Tuesday October 14, 2014 (in class).
• Final exam^*: December 17, 2014, 3:30-5:30pm in our regular classroom, Lopata 101.
• ACADEMIC INTEGRITY: Please make sure you are familiar with Washington University Academic Integrity Policy, as it will be strictly applied.

^* EXCEPT FOR PROPERLY DOCUMENTED MEDICAL OR FAMILY EMERGENCY REASONS, THERE WILL BE NO MAKE-UP TIMES FOR EXAMS. YOU NEED TO ARRANGE OTHER ACTIVITIES SO AS TO AVOID CONFLICTS.

Course Structure

Class format: Ideally, each "lecture" should be highly interactive and spent either digging into specific concepts you may not have fully understood (in responses to questions you will need to ask), or working through some problems that require that you apply the material being targeted for this particular lecture. In order for this to work, it means that you MUST have read ahead of time the material expected to be covered during the lecture. This material will be identified by date in the Reading Assignment column of the syllabus on the wiki. Working through the problems will require access to the book and possibly other material, so that you should bring a laptop to class.

Reading Assignments (and preparing for quizzes & exams): As mentioned, reading assignments are intended to prepare you for the next lecture. Reading assignments will also often include additional material beyond the textbook, and in particular, Requests for Comments (RFCs) that are the "standards" documents of the Internet Engineering Task Force(IETF). In most instances, except for the topic of network security (Attacks & Defenses) where the book only has limited coverage, you will not been expected to have read those RFCs ahead of class. Material that is not required reading before a class will be listed on a separate line starting with FYI. Note though that some of the problems will require retrieving information from those documents, so having some familiarity with their content ahead of class wont hurt.

In addition to the reading assignments and the questions we will explore in class, there is a wealth of material that is available with the Kurose & Ross textbook. In particular, the textbook's student resources include many problems, exercises, and labs that can help you assess and improve your understanding of the class material. You are strongly encouraged to take advantage of those resources, and, for example, for small study groups of 2-3 students to work through them and discuss possible solutions.

Review Questions: Will be assigned ahead of each class. They are meant to test your understanding of both previous material and more importantly the reading assignment material, and need to be turned in at the start of the class. As an added incentive for you to work through the questions, they will be checked to assess that you have made an honest attempt at completing them. Review questions make-up 10% of your grade, and your overall score will depend on how many reasonably answered questions you turn in.

Quizzes: There will be six quizzes that will together count for 20% of your overall grade. Quizzes are scheduled approximately every second week to alternate with labs due dates. Quizzes will take place at the start of class (so don't be late) and will take 15 minutes. Your lowest quizz score will be discarded (alternatively, you can miss one quizz). Like with exams, there will be no make-ups or adjustments for missed quizzes except for duly documented medical or family emergency reasons.

Studios: There are five studios that are all optional and meant to prepare you for the labs. Two TAs will be available to assist you with studios on Wednesday 5:30-7:00pm & Friday 10:00-11:30am in Urbauer 216. Studios are not graded and nothing needs to be turned in. They are expected to be completed in small groups (4) to allow for interactions and discussions of the material.

Code needed to complete each one of the studios will be made available under a correspondingly named directory in the SVN repository that you have been assigned for the class. Descriptions of each individual studio are provided in pdf format in the Optional studios section of the wiki.

Labs: There are five lab assignments that involve applying some of the material covered in the class, either by observing the behavior of networked systems or by developing simple versions of some basic network software components. Several of the assignments will be done using the Open Network Lab (ONL), and you will need to first get an ONL account. Labs involve multiple components from developing your software to testing it using the ONL machines and network. Getting all the pieces to work well together is likely to take multiple iterations, so don't wait until the last minute to get started on your lab. It's a recipe for disaster.

Code needed to complete each one of the labs will be made available under a correspondingly named directory in the SVN repository that you have been assigned for the class. Descriptions of each individual lab are provided in pdf format in the Labs section of the wiki.

The first two labs must be completed individually by each student. Subsequent labs can be done in teams of two if so desired. A team only needs to turn in one lab assignment, and unless warranted by exceptional conditions, both team partners receive the same lab. You can discuss labs with other students, but what you turn in must be your own. In particular, because the labs heavily rely on labs from previous years (although differences have been introduced), trying to earlier years' solutions will expose you to severe penalties, including possibly failing the course. If you are ever in doubt regarding what material is appropriate for you to use, please ask me. Labs will count towards 25% of your overall grade.

Exams: The course has two exams, a midterm (20% of your overall grade) and a final (25% of your overall grade). The midterm will take place in-class during the class of Tuesday October 14, 2014. The exam will be held during the time-slot allocated by the university, i.e., on Wednesday December 17, 2014, 3:30-5:30pm. The final will be cumulative in its scope, i.e., include everything that has been covered during the class.