eec-484/584 computer networks lecture 1 wenbing zhao cleveland state university [email protected]

EEC-484/584EEC-484/584Computer NetworksComputer Networks

Lecture 1Lecture 1

Wenbing ZhaoWenbing ZhaoCleveland State UniversityCleveland State University

[email protected]@ieee.org

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Fall 2008Fall 2008 EEC-484/584: Computer NetworksEEC-484/584: Computer Networks Wenbing ZhaoWenbing Zhao

Instructor InformationInstructor Information

• Instructor: Dr. Wenbing Zhao– Office: SH434– Email: [email protected]– Lecture: MW 4:00-5:50pm, SH306– Office hours: MW 2:00-4:00pm and by appointment

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What is Computer Network?What is Computer Network?

A group of computers inter-connected together

Local Area Network

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What is Computer Network?What is Computer Network?

A group of computer inter-connected together

Wide Area Network

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What are the ElementsWhat are the Elementsin a Computer Network?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 EasyAchieving Connectivity is Not Easy

• Layered approach

• We will study the issues in each layer in a hybrid order– Application– Link– Network– Transport

application

transport

network

link

physical

Transport Service Provider

Transport Service User

Physical Layer is not covered

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Course ObjectivesCourse 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 Prerequisite (for graduate students)(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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TopicsTopics

• 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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TopicsTopics

• Application Layer– HyperText Transfer Protocol (HTTP)– Domain Name Service (DNS)– FTP, Email

• Physical Layer: skipped

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TopicsTopics

• 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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TopicsTopics

• Data Link Layer (part 2): Medium access control protocols– Shared medium, multiple concurrent users,

need to address conflict

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TopicsTopics

• 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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TopicsTopics

• Transport layer– Main service: End-to-end reliable communication– User Datagram Protocol (UDP)– Transport Control Protocol (TCP)

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LabsLabs

• Purpose: Observe how protocols work

• Tools used: Wireshark

• 5 lab sessions– HTTP– DNS– Ethernet, ARP & DHCP– IP– TCP

“Tell me and I forget. Show me and I remember. Involve

me and I understand.”- Chinese proverb

Lab instructions taken from Kurose’s book

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LabsLabs

• 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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ProjectsProjects• 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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ProjectsProjects• 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

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ProjectsProjects• 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 ParticipationClass 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 ParticipationClass 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 ParticipationClass 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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QuizzesQuizzes• 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 Perks: only the best of 4 quizzes will be counted

towards your gradetowards your grade

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GradingGrading• Class participation 10%• Quizzes 50%• Labs 20%• Project 20%

– For graduate students• Proj#1: 5%• Proj#2: 15%

• Grading scale:– 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 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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Consequences for CheatingConsequences 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 TextsReference 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 InformationAdditional Information

• Anonymous email:– [email protected]– 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

eec-484/584 computer networks lecture 1 wenbing zhao cleveland state university [email protected]

Documents

computer networks lecture

computer networks elements

communication slide

skipped slide

connectionless slide

dhcp slide

conflict slide

appointment slide