Hayder Al-Ghanimi
University of Babylon
College of Information Technology
Department of Software

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Lectures time
Objectives
Assessment
structure and contents
Materials
Some goals of computer networks
Overview on computer Networks

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Every week at 11:30 on Monday.
Practical lecture
 Group A
 Group B at 8:30 AM at 10:30 AM

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To understand the basic principles of networks,
Protocols and the Internet.
To appreciate the complex trade-offs that are inherent in the design of networks.
To provide a guided tour of network technologies from the lowest levels of data transmission up to network applications.
To learn about current networking technologies, especially Internet protocols (IP).

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Theoretical lecture ( 18 marks)
 Every Lecture are divided into two parts
▪ First 30 min. would be used to test the previous topic
▪ The rest of time, we will carry on with new topic
▪ At the end of the term all the exams would be used.
Practical lecture (32 marks)
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 Depends on the lecturer in a lab.
The end-term exam (50 marks)

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TCP/IP protocol suite book, Buhrouze
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Computer Networks and Internets, Douglas E.
Comer, Prentice Hall
J. Kurose and K. Ross, Computer Networking: A
Top-Down Approach, 4th Edition, Addison
Wesley, 2007.

 key concepts in networking
 Protocols
 Layering
 Resource allocation
 Security
 how the Internet works
 Internet architecture
 IP protocol suite
 Applications (FTP, HTTP, SMTP)
 Skill: network programming
 Socket programming
 Designing and implementing protocols

An interconnection of autonomous computers

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In computer networks, communication occurs between entities in different systems. An entity is anything capable of sending or receiving information. However, two entities cannot simply send bit streams to each other and expect to be understood. For communication to occur, the entities must agree on a protocol. A protocol is a set of rules that govern data communications. A protocol defines what is communicated, how it is communicated, and when it is communicated. The key elements of a protocol are syntax, semantics, and timing.
Syntax: how a communication is specified & structured
▪ Format, order messages are sent and received
Semantics: what a communication means
 Actions taken when transmitting, receiving, or when a timer expires
Timing: when data should be sent AND how fast they can be sent

 Interconnect heterogeneous networks and provide universal service
 Hardware: routers connect different networks
 Internet protocols: provide universal service by creating a single virtual network
An internet (note the lowercase letter i) is two or more networks that can communicate with each other. The most notable internet is called the Internet (uppercase letter I), a collaboration of more than hundreds of thousands of interconnected networks.
Private individuals as well as various organizations such as government agencies, schools, research facilities, corporations, and libraries in more than 100 countries use the Internet.
Millions of people are users. Yet this extraordinary communication system only came into being in 1969.

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Access to remote resources
Human communication
Mobile computing
Computing power through parallelism
Optimising resources - load balancing
Incremental growth of computer systems
(reduced cost and risk)

 Email, World Wide Web, Video Conferencing, File
Transfer, Collaborative Virtual Environments,
Remote control of robots and machines, Dial up databases, Distributed Programs, Hacking,
Banking, Internet telephone

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By size
 Local area networks (LANs) versus Wide area networks (WANs)
By connectivity
 Point to point versus broadcast networks
By communication medium
By mobility
 Fixed versus mobile

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‘Speed’ - bandwidth and latency
Management
Security
Reliability
Billing
Heterogeneity (and standards)

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‘Speed’ - bandwidth and latency
Range
Sharing
Topology
Installation and maintenance costs
Reliability

 Mobile networking has emerged in the last decade. Introduces new issues of:
 energy efficiency
 location and tracking
 semi-persistent connections
 complex administration and billing as devices and users move around the network

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Addressing
Routing
Framing and encoding
Error detection and correction
Flow and congestion