EEC-484/584
Computer Networks
Lecture 1
Wenbing Zhao
wenbing@ieee.org
2
Instructor Information
• Instructor: Dr. Wenbing Zhao
–
–
–
–
Spring 2008
Office: SH434
Email: wenbing@ieee.org
Lecture: MW 4:00-5:50pm, SH306
Office hours: MW 2:00-4:00pm and by appointment
EEC-484/584: Computer Networks
Wenbing Zhao
3
What is Computer Network?
A group of computers inter-connected together
Local Area Network
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
4
What is Computer Network?
A group of computer inter-connected together
Wide Area Network
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
5
What are the Elements
in a Computer Network?
• Hosts – computers
• Communication medium – cables, wireless
medium (EM waves)
• Routers – forward a packet from one place
to another, decide on a path from source
to destination
• Protocols – rules governing the
communication
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
6
Achieving Connectivity is Not Easy
Transport Service User
• Layered approach
• We will study the issues in
each layer in a hybrid order
– Application
– Link
– Network
– Transport
transport
network
Physical Layer is not covered
Spring 2008
application
Transport
Service
Provider
EEC-484/584: Computer Networks
link
physical
Wenbing Zhao
7
Course Objectives
• Good understanding of the computer
networking technologies
– How connectivity is achieved?
• Hands on experience
– Labs: observe how protocols work
– Project: write about computer networks
elements and hopefully write some demo
programs
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
8
Prerequisite (for graduate students)
• Officially: graduate standing
• Actually: I assume you have sufficient
computer engineering background
– You have taken undergraduate-level
operating systems, data structure and
algorithms, and programming language
courses
– You know how to write technical reports in
English (in your own words)
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
9
Topics
• Overview of computer networks
– Types of computer networks
– Reference models
– Protocols, services and interfaces
– Circuit switched vs. packet switched
– Connection oriented vs. connectionless
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
10
Topics
• Application Layer
– HyperText Transfer Protocol (HTTP)
– Domain Name Service (DNS)
– FTP, Email
• Physical Layer: skipped
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
11
Topics
• Data Link Layer (part 1):
Basic communication protocols
– Main service: provide point-to-point single hop
communication service to higher layer
– Framing: group bits together
– Error control
– Flow control
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
12
Topics
• Data Link Layer (part 2):
Medium access control protocols
– Shared medium, multiple concurrent users,
need to address conflict
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
13
Topics
• Network layer
– Main service: routing over multiple hops
– Routing algorithms
– Internet Protocol (IP)
– IP address allocation
– Internet Control Protocols: ICMP, ARP, DHCP
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
14
Topics
• Transport layer
– Main service: End-to-end reliable communication
– User Datagram Protocol (UDP)
– Transport Control Protocol (TCP)
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
15
Labs
• Purpose: Observe how protocols work
• Tools used: Ethereal/Wireshark
• 5 lab sessions “Tell me and I forget. Show
–
–
–
–
–
HTTP
me and I remember. Involve
DNS
me and I understand.”
Ethernet & DHCP
- Chinese proverb
IP
TCP
Lab instructions taken from Kurose’s book
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
16
Labs
• Lab sessions are mandatory unless an
exception is granted in advance
• I will not accept the lab report if you do now
show up during the lab session without prior
notice
• Lab report must be typed (with both questions
and answers) and submitted in hardcopy on or
before due date
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
17
Projects
• There are two required projects
– Both are closely related to the information
literacy program sponsored by the CSU
library
• For individual or a team of two
• To gain extra-credit, you are encouraged
to build demonstration programs
– Java applet or plain Java application,
– NS2 simulator
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
18
Projects
• Project #1: Select a topic in Chapters 1, 3,
and 7, and build a wiki page for the topic
on http://www.pbwiki.com/.
• Example topics are:
–
–
–
–
–
–
Introduction to computer networks
Internet history
ISO/OSI reference model
TCP/IP model
World Wide Web, HTTP, DSN
Data link layer design principles
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
19
Projects
• Project #2: Select a topic in Chapters 4, 5,
6, and build a wiki page for the topic on
http://www.pbwiki.com/
– For example topics, see the syllabus
• As part of Project #2, peer-review and
revision steps are involved
– Each team is required to review three wiki
pages built by other teams anonymously
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
20
Information Literacy Workshop
• Will be taught by librarian:
Theresa M. Nawalaniec
• Main activity: learn how to perform
literature search
• When: Feb 11, Monday, 4-5:45pm
• Where: CSU library RT502
• Attendance mandatory: if you miss this
workshop, I will not accept your project
reports
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
21
Class Participation
• 10% of the course credit
• In general, there is a mock quiz in the beginning
of each lecture, so that
– I know who is here & I get feedback for my teaching
• To obtain the full credit for class participation,
you must satisfy ALL of the following conditions:
– You do not miss more than 2 lectures
– You do not miss any quiz and lab sessions
– You asked at least 10 questions during the semester
• You will lose all 10% credit if you miss more than
6 lectures/labs (unless an exception is granted)
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
22
Class Participation
• Send me an email with the following information
for each question you have asked within 24
hours after each lecture:
– The question you asked
– My response
– Your comment on my response and suggestion for
improvement, if any
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
23
Class Participation
• You are also encouraged to send me
comments/suggestions on how you would like
me to improve my teaching so that it is more
conducive
• For each piece of comment/suggestion, it will be
counted as 2 questions
• If you max out the class participation credit, you
will get extra credit if you provide further
feedbacks
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
24
Quizzes
• 5 quizzes. Basically one quiz for each layer
• Each quiz is designed for 1 hour (you have 1h
50 minutes to work on it)
• The quizzes are closed book and closed notes,
except that you are allowed to bring with you a
one-page cheat sheet no larger than the US
letter size (double-sided allowed)
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
25
Quizzes
• No makeup quizzes!
• No midterms and final exam
• Perks: You have two options to improve
your credit on the quizzes:
– The weight of the best quiz is doubled
– The weight of the worst quiz is halved
Whichever is favorable to you
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
26
Grading
•
•
•
•
Class participation 10%
Quizzes 40%
Labs 20%
Project 30%
– Proj#1: 5%
– Proj#2: 25%
Spring 2008
• Grading scale:
–
–
–
–
–
–
–
A: 90-100%
A-: 85-89%
B+: 75-84%
B: 65-74%
B-: 60-64%
C: 50-59%
F: < 50%
EEC-484/584: Computer Networks
Wenbing Zhao
27
Do not cheat!
• Do not copy other student’s lab report, quizzes
or projects
• Do not copy someone else’s work found on the
Internet
– You can quote a sentence or two, but put those in
quote and give reference
– You can build your projects on top of open source
libraries, but again, you need to explicitly give
acknowledgement and state clearly which parts are
implemented by you
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
28
Consequences for Cheating
• You get 0 credit for the project/lab/quiz that you
have cheated
• If the task is worth more than 25% of the course,
it is considered a major infraction
• Otherwise, it is considered a minor infraction
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
29
Consequences for Cheating
• For major infraction and repeated minor
infractions
– You will get an F grade, and
– You may be suspended or repulsed from CSU
• CSU Code of Conduct
– http://www.csuohio.edu/studentlife/conduct/StudentC
odeOfConduct2004.pdf
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
30
Reference Texts
• Andrew S. Tanenbaum :
– Computer Networks
• 4th Edition, Prentice-Hall, 2003
• James F. Kurose, Keith W. Ross,
– Computer Networking: A Top-Down
Approach Featuring the Internet
• 3rd Edition, Addison-Wesley, 2004
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
31
Additional Information
• Anonymous email:
– teachingcsu@gmail.com
– Password:
– if you are not happy, please do let me know
• Course Web site:
– http://academic.csuohio.edu/zhao_w/teaching
/EEC584-S08/eec584.htm
– Lecture notes will be posted
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao
32
Homework
• Due Jan 14, 11:59pm (today midnight!)
• Email me the following information
– The amount of time per week you commit to this
course
– The grade you expect to get
– If your schedule conflicts with my office hours, what is
the best time for you to talk to me?
– Comments and suggestions, if any
Spring 2008
EEC-484/584: Computer Networks
Wenbing Zhao