EEC-484/584
Computer Networks
Lecture 1
Wenbing Zhao
Cleveland State University
wenbing@ieee.org
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Instructor Information
• Instructor: Dr. Wenbing Zhao
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Fall 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
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What is Computer Network?
A group of computers inter-connected together
Local Area Network
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What is Computer Network?
A group of computer inter-connected together
Wide Area Network
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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
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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
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application
Transport
Service
Provider
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physical
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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
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Prerequisite (for graduate students)
• Officially: graduate standing
• Ideally: You should 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)
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Topics
• Overview of computer networks
– Types of computer networks
– Reference models
– Protocols, services and interfaces
– Circuit switched vs. packet switched
– Connection oriented vs. connectionless
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Topics
• Application Layer
– HyperText Transfer Protocol (HTTP)
– Domain Name Service (DNS)
– FTP, Email
• Physical Layer: skipped
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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
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Topics
• Data Link Layer (part 2):
Medium access control protocols
– Shared medium, multiple concurrent users,
need to address conflict
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Topics
• Network layer
– Main service: routing over multiple hops
– Routing algorithms
– Internet Protocol (IP)
– IP address allocation
– Internet Control Protocols: ICMP, ARP, DHCP
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Topics
• Transport layer
– Main service: End-to-end reliable communication
– User Datagram Protocol (UDP)
– Transport Control Protocol (TCP)
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Labs
• Purpose: Observe how protocols work
• Tools used: Wireshark
• 5 lab sessions “Tell me and I forget. Show
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HTTP
me and I remember. Involve
DNS
me and I understand.”
Ethernet, ARP & DHCP - Chinese proverb
IP
TCP
Lab instructions taken from Kurose’s book
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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
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Projects
• Build two wiki pages
– Project#1 is waived for undergraduate students
• 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
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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:
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Introduction to computer networks
Internet history
ISO/OSI reference model
TCP/IP model
World Wide Web, HTTP, DSN
Data link layer design principles
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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
– For undergraduate students, any topic from the
course
• 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
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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)
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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
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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
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Wenbing Zhao
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Quizzes
• 5 quizzes. Basically one quiz for each layer
• The quizzes are closed book and closed notes,
except that you are allowed to bring with you a
one-page hand-written cheat sheet no larger
than the US letter size (double-sided allowed)
• No makeup quizzes!
• No midterms and final exam
• Perks: only the best of 4 quizzes will be counted
towards your grade
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Wenbing Zhao
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Grading
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Class participation 10%
Quizzes 50%
Labs 20%
Project 20%
– For graduate students
• Proj#1: 5%
• Proj#2: 15%
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• Grading scale:
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A: 90-100%
A-: 85-89%
B+: 75-84%
B: 65-74%
B-: 60-64%
C: 50-59%
D: 40-49%
(undergraduate only)
– F: < 50% (or < 40%)
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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
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Wenbing Zhao
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Consequences for Cheating
• You get 0 credit for the task 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
• 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/StudentCodeOfCondu
ct.pdf
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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
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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/EEC484
-F08/eec584.htm
– Lecture notes will be posted
Fall 2008
EEC-484/584: Computer Networks
Wenbing Zhao