1. CSE 422 Computer Networks Dr. Abdol-Hossein Esfahanian
Sunday, April 16, 2017
CSE 422 Computer Networks
Dr. Abdol-Hossein Esfahanian
Computer Science and Engineering Department
3115 Engineering Building
© by A-H. Esfahanian. All Rights Reserved.

2. Catalog Description CSE 422: Computer Networks
Sunday, April 16, 2017
Catalog Description
CSE 422:  Computer Networks
Prerequisite: (STT 351 or ECE 280) and (CSE 320 or ECE 331) and (CSE 410 or concurrently)
Description: Computer network architectures and models. Physical media and signaling. Data link protocols. Medium access control. Routing and IP. Transport services including TCP/UDP. Network applications. Local-area and wide-area networks.
© by A-H. Esfahanian. All Rights Reserved.

3. Course Objectives Learn the fundamentals of computer networking.
Sunday, April 16, 2017
Course Objectives
Learn the fundamentals of computer networking.
Understand how these fundamentals are applied in real networks, in particular, the Internet.
Understand the relationship between theory and practical design issues in network hardware and software.
Gain an in-depth understanding of how network applications software is supported by underlying protocols.
Learn that computer networks evolve.
© by A-H. Esfahanian. All Rights Reserved.

4. Course Outline Introduction Physical Layer
Sunday, April 16, 2017
Course Outline
Introduction
Overview of computer networks
Network architecture models
Network programming interfaces
Physical Layer
Services provided to the data link layer
Theoretical basis for data communication
Bandwidth limitations
Analog and digital transmission
Transmission media
Signaling methods
Multiplexing and switching
Wireless/Mobile communication
© by A-H. Esfahanian. All Rights Reserved.

5. Course Outline … Data Link Layer Medium Access Sublayer Network Layer
Sunday, April 16, 2017
Course Outline …
Data Link Layer
Services provided to the network layer
Error detection and correction
Stop-and-wait protocols
Sliding window protocols
Medium Access Sublayer
Channel allocation problems
Contention-based protocols
Ethernet architecture
802.x protocols
Network Layer
Services provided to the Transport layer
Routing algorithms
Internetworking
Internet Protocol
© by A-H. Esfahanian. All Rights Reserved.

6. Course Outline… Transport Layer Application-level Protocol Standards
Sunday, April 16, 2017
Course Outline…
Transport Layer
Services provided to the upper layers
Connection management
UDP, TCP, sockets
Performance issues
Application-level Protocol Standards
Domain name services
Application standards: SNMP, FTP, TELNET, SMTP, NNTP, HTTP
Network Security
Introduction to Cryptography
Public-key algorithms
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7. Class Procedures and Policies
Sunday, April 16, 2017
Class Procedures and Policies
Class attendance and participation (5%)
Homework & Labs (15%)
Two exams (25% each) and a final (30%)
Course Grade is based on straight scale; percentages are on total scores possible:
93 – 100%
4.0
85 – 92 %
3.5
80 – 84 %
3.0
75 – 79 %
2.5
70 – 74 %
2.0
65 – 69 %
1.5
60 – 64 %
1.0
© by A-H. Esfahanian. All Rights Reserved.

8. Sunday, April 16, 2017
Class Procedures ……..
Class notes and other course materials and resources will be available on the course website:
It is password protected (cse422, tan4me).
Visit this site on regular basis. It is your responsibility!
© by A-H. Esfahanian. All Rights Reserved.

9. Sunday, April 16, 2017
Class Procedures
When attending the class, we ask you to observe a few simple rules which are meant to create a better learning environment.
Come to class on time since we will start lectures right away.
Once class begins, we expect students to pay attention and not read the newspaper or talk, etc. TURN YOUR CELL PHONE OFF.
If you have a question, do not hesitate to ask.
Others are likely to have the same question.
Do not be afraid to ask questions and slow down the pace of the class. If we feel there are too many questions and that we must move on, we will say so, but that should not be taken to mean that the question was ``dumb'' or inappropriate.
© by A-H. Esfahanian. All Rights Reserved.

10. Sunday, April 16, 2017
Class Procedures …
Textbook: Computer Networks, by Andrew Tanenbaum, Fourth Edition.
Students are required to get a copy of this textbook. You will have regular reading assignments from this textbook.
© by A-H. Esfahanian. All Rights Reserved.

11. Class Procedures … Instructor: Dr. Abdol-Hossein Esfahanian
Sunday, April 16, 2017
Class Procedures …
Instructor: Dr. Abdol-Hossein Esfahanian
Url:
Office: 2134EB
Tel:
Office Hours: Wed 1:00pm – 2:00pm, or by appointment, or whenever you can find me.
© by A-H. Esfahanian. All Rights Reserved.

12. Class Procedures … Course TA: Bo Wang [wangbo@msu.edu]
Sunday, April 16, 2017
Class Procedures …
Course TA: Bo Wang
Office hours will be on Thursdays noon.
© by A-H. Esfahanian. All Rights Reserved.

13. Sunday, April 16, 2017
Class Procedure …
All students will have computer accounts on CSE machines. If your home account is under another domain, then it is your responsibility to have your mail forwarded.
Students are encouraged to work together on homework assignments. However, each student must do his/her write-up.
Unless otherwise specified, exams will be closed-book and will cover material assigned from the texts, notes, handouts, and lectures. For exams only, you are allowed to use an 8½ x 11 note sheet. You should utilize this to write down important formulae, proof techniques etc.
Being caught cheating on ANY aspect of the course is grounds for receiving a grade of 0.0 for the course.
© by A-H. Esfahanian. All Rights Reserved.

14. Sunday, April 16, 2017
Academic Integrity
Academic Integrity is very important in this class and in this university. It is important that students do their work on their own without help from anyone except the instructor or the teaching assistant. Students are permitted to discuss the homework problems with each other. However, the work they turn in must be completely their own. Obviously, no cooperation is permitted during examinations. Students violating this will be dealt with according to the university policy.
© by A-H. Esfahanian. All Rights Reserved.

15. Make note of these dates. Normally there will NOT be any
Sunday, April 16, 2017
Important dates
Exam #1
Thursday Feb 22, 2007
Exam #2
Thursday April 5, 2007
Final:
Thursday May 3, 2007, 10:00-12:00 noon
Make note of these dates. Normally there will NOT be any
make-up exams.
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16. Technologies over the centuries
Sunday, April 16, 2017
Technologies over the centuries
18th Century: Mechanical Systems Accompanying The Industrial Revolution
19th Century: Age of The Steam Engine
20th Century: Information Gathering, Processing, and Distribution. Examples:
Worldwide Telephone Network
Invention of Radio and TV
Computer Industry
Launching of Communication Satellites
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17. A brief history of Networking
Sunday, April 16, 2017
A brief history of Networking
: Early packet-switching principles
1972:
ARPAnet demonstrated publicly
NCP (Network Control Protocol) first host-host protocol
First program
ARPAnet has 15 nodes
1961: Kleinrock - queuing theory shows effectiveness of packet-switching
1964: Baran - packet-switching in military nets
1967: ARPAnet conceived by Advanced Research Projects Agency
1969: First ARPAnet node operational
© by A-H. Esfahanian. All Rights Reserved.

18. Networking History (Cont.)
Sunday, April 16, 2017
Networking History (Cont.)
: Internetworking, new and proprietary nets
Cerf and Kahn’s internetworking principles:
minimalism, autonomy - no internal changes required to interconnect networks
best effort service model
stateless routers
decentralized control define today’s Internet architecture
1970: ALOHAnet satellite network in Hawaii
1973: Metcalfe’s PhD thesis proposes Ethernet
1974: Cerf and Kahn - architecture for interconnecting networks
late70’s: Proprietary Architectures: DECnet, SNA, XNA
late 70’s: switching fixed length packets (ATM precursor)
1979: ARPAnet has 200 nodes
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19. Networking History (Cont.)
Sunday, April 16, 2017
Networking History (Cont.)
: new protocols, a proliferation of networks
new national networks: Csnet, BITnet, NSFnet, Minitel
100,000 hosts connected to confederation of networks
1983: deployment of TCP/IP
1983: smtp protocol defined
1983: DNS defined for name-to-IP-address translation
1985: ftp protocol defined
1988: TCP congestion control
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20. Networking History (Cont.)
Sunday, April 16, 2017
Networking History (Cont.)
1990’s: commercialization, the WWW
Early 1990’s: ARPAnet decommissioned
1991: NSF lifts restrictions on commercial use of NSFnet (decommissioned, 1995)
early 1990s: WWW
hypertext [Bush 1945, Nelson 1960’s]
HTML, http: Berners-Lee
1994: Mosaic, later Netscape
late 1990’s: commercialization of the WWW
Late 1990’s:
est. 50 million computers on Internet
est. 100 million+ users
backbone links running at 1 Gbps
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21. The ARPANET Growth of the ARPANET (a) December 1969. (b) July 1970.
Sunday, April 16, 2017
The ARPANET
Growth of the ARPANET (a) December (b) July 1970.
(c) March (d) April (e) September 1972.
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22. Hosts on the Web Sunday, April 16, 2017
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23. Source: http://www.websiteoptimization.com/bw/0611/
Sunday, April 16, 2017
Over the past year, the UK added a net increase of 6.1 subscribers per 100 inhabitants. The US added 4.7 subscribers, while Japan added 2.6. The UK's superior growth rate propelled it past the US and Japan to become second only to Canada among G7 countries surveyed in broadband penetration.
Source:
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24. Total Broadband Subscribers
Sunday, April 16, 2017
Total Broadband Subscribers
OECD; Organization for Economic Co-operation and Development
The OECD groups 30 member countries sharing a commitment to democratic government and the market economy. With active relationships with some 70 other countries and economies, NGOs and civil society, it has a global reach. Best known for its publications and its statistics, its work covers economic and social issues from macroeconomics, to trade, education, development and science and innovation.
Over the past year, the US has maintained its lead with 31% of total broadband subscribers worldwide.
Source:
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25. Broadband Penetration by Country and Population Density - June 2006
Sunday, April 16, 2017
Broadband Penetration by Country and Population Density - June 2006
Source:
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26. Lecture 01 Tuesday January 09, 2007
Sunday, April 16, 2017
Lecture 01 Tuesday January 09, 2007
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27. Notable Read Chapter 1 Read the article Nothing but Net
Sunday, April 16, 2017
Notable
Read Chapter 1
Read the article Nothing but Net
Forthcoming Topics
What is a computer network
Classification of networks
The layering concept
© by A-H. Esfahanian. All Rights Reserved.

28. What is a Computer Network?
Sunday, April 16, 2017
What is a Computer Network?
A computer network is an interconnected collection of autonomous computers.
Two computer are interconnected if they are able to exchange information
Two computer are autonomous if they are capable of operating independently, that is, neither is capable of forcibly starting, stopping, or controlling the other.
© by A-H. Esfahanian. All Rights Reserved.

29. What is not a Computer Network?
Sunday, April 16, 2017
What is not a Computer Network?
Master/slave systems, in which one computer controls several others
single-host networks, consisting of a single computer with an attached collection of terminals.
Multicomputers, such as the old hypercube, which normally operate as a back-end to a host system.
In terms of (operating) systems, there is some confusion between network systems and distributed systems
© by A-H. Esfahanian. All Rights Reserved.

30. Sunday, April 16, 2017
Network Systems
An interconnection of computers through a communication subnet
The user is aware of the networking of different computers
Network services
remote login
remote file transfer
remote job execution
mail service
Etc,
© by A-H. Esfahanian. All Rights Reserved.

31. Sunday, April 16, 2017
Distributed Systems
A distributed system is a special case of computer network, in which the network of computers appears as a single system to the user, all operations being performed transparently.
Combination of an interconnection of computers and distributed control programs.
Most operations are transparent to the user.
User sees an integrated service environment; distributed system is hidden from the user.
© by A-H. Esfahanian. All Rights Reserved.

32. Distributed Systems … Provides location-independent services.
Sunday, April 16, 2017
Distributed Systems …
Provides location-independent services.
The difference lies with the software rather than hardware.
Allows concurrent processing and greater sharing of resources
Permits development of distributed application programs
Ongoing problems in distributed systems
load balancing
fault-tolerance
© by A-H. Esfahanian. All Rights Reserved.

33. Applications of Networks
Sunday, April 16, 2017
Applications of Networks
Access to Remote Programs
Simulation
Computer Aided Ed.,
Medical Diagnosis
Access to Remote Data Bases
Reservations For Hotels, Airplanes
Home Banking
Automated Newspaper
Automated Library
Access to Information System: (e.g. World Wide Web)
© by A-H. Esfahanian. All Rights Reserved.

34. Applications of Networks…
Sunday, April 16, 2017
Applications of Networks…
Communication Medium
Electronic Funds Transfer System
Electronic Mail
Teleconferencing
Worldwide Newsgroups
International Contacts by Humans
Entertainment Industry
Video On Demand
Multiperson real-time simulation games
Selecting any movie/TV program ever made
Live TV may become interactive with audience
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35. Social Issues Views on politics, religion, …., become distributed
Sunday, April 16, 2017
Social Issues
Views on politics, religion, …., become distributed
Newsgroups debate sensitive issues
Network operators risk being sued for contents
Rights to free speech may be violated
Anonymous messages can be desirable, but ...
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36. Network Classification based on physical size
Sunday, April 16, 2017
Network Classification based on physical size
Typical Distance
Area covered
System Type
10m – 1Km
Room, Building Campus
Local Area Networks
10 – 100Km
City, County, Continent
Metropolitan Area, Wide Area Network
Over 100Km
Planet
Internet
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37. Network Structure Communication Subnet (Subnet)
Sunday, April 16, 2017
Network Structure
Communication Subnet (Subnet)
Switching Elements (Routers)
Transmission Lines (Circuits)
Boundary of the
Communication subnet
Routers
Hosts
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38. Types of Design For Subnets
Sunday, April 16, 2017
Types of Design For Subnets
Point-to-Point Circuits (Channels)
(a)
(b)
(c)
(d)
(e)
(f)
Some possible topologies for a point-to-point subnet
(a) Star (b) Loop (c) Tree (d) Complete (e) Intersecting loops (f) Irregular
© by A-H. Esfahanian. All Rights Reserved.

39. Types of Design For Subnets…
Sunday, April 16, 2017
Types of Design For Subnets…
Broadcast Channels
(a)
(b)
(c)
Communication subnet using broadcasting
(a) Bus (b) Satellite or Radio (c) Ring
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40. Types of Design For Subnets…
Sunday, April 16, 2017
Types of Design For Subnets…
Broadcast Subnets May Allocate Channel By:
Static Method
TDMA
Dynamic Methods
Centralized
Decentralized
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41. Classification based on switching techniques
Sunday, April 16, 2017
Classification based on switching techniques
Circuit-switched networks
A physical circuit must be established between the two communicating stations before any exchange of information.
Packet-switched networks
No physical circuit is established in advance.
The message is stored and then forwarded at each intermediate node.
© by A-H. Esfahanian. All Rights Reserved.