Hayder Al-Ghanimi

University of Babylon College of Information Technology

Department of Software

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

Every week at 11:30 on Monday.

Practical lecture

Group A at 8:30 AM

Group B at 10:30 AM

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).

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)

Depends on the lecturer in a lab.

The end-term exam (50 marks)

TCP/IP protocol suite book, Buhrouze 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

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.

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

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

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

star tree

irregular

mesh

satellite/radio

‘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

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