Computer Networks

Rationale:

Virtually every computer is connected, or has the potential to be connected, to other computers. When connected locally, they provide vital services such as printing, file servers, CPU servers and electronic mail. When connected over a wide area they support the exchange of information in many forms. Millions of people world wide have been exposed to the World Wide Web of computers and the information they provide.

The explosion in the use of such intranets and the long established use of local area networks has made the study of computer networks and the underlying communication technology as important as the more traditional foundations of computer science such as computer architecture, operating systems and programming.

Aims:

• To develop an understanding of the modern network technologies in common use today
• To make informed decisions regarding the selection, purchase, installation and maintenance of local and wide area networks
• To identify potential and actual problems with existing networks and identify advances in technology that may solve them

Objectives: 

• To understand the physical properties, performance characteristics and costs of communication media; specifically copper cable and fibre optics
• To understand the application of existing point to point data communication standards, including enhancements to those standards
• To appreciate the theory and practice of common local area networks
• To show how networks of different standards can be inter-connected
• To appreciate the significance of network and inter-network protocols; specifically the TCP/IP
• To understand the importance of network security and reliability, including examples of error recovery strategies and encryption systems

Content:

1 INTRODUCTION

• Historical perspective, theoretical and practical models of network architecture particularly the ISO OSI and TCP/IP Models. Example networks and services including prototype new technologies. These would include X.25, Frame Relay, ISDN and ATM.

2 DIGITAL COMMUNICATION

• Physical properties of copper media, fibre optics, radio communication, data communication standards. Maximum data rates (theoretical and practical) for different media including some simple analysis of signals. Data encoding of digital signals. The distinction between, and analysis of, physical media and wireless media properties. The difference between narrow band and broad band technologies with particular reference to ISDN and ATM.

3 LOCAL AREA NETWORKS

• Types of LAN covering standards, topology and performance. Example architectures such as ethernet and fast ethernet, token ring, FDDI and ATMs. Wireless LANs and emerging technologies. Bridges and routing.

4 WIDE AREA NETWORKS

• Circuit vs packet switching and associated routing and flow control. Detailed examples of existing and emerging architectures such as frame relay and ATM.

5 INTER NETWORKS

• Principles of inter networking, architectures and protocols. Particular reference to TCP/IP.

6 ERRORS

• The main causes of errors and the effect on transmission. Single bit and burst errors. Various error detection and correction strategies including parity, block sum, Hamming Codes and Cyclic Redundancy Checks. Forward vs backward error control. Statistical analysis of the effectiveness of error detection and correction code.

7 NETWORK SECURITY

• Requirements of security and types of attack. Private vs public keys and electronic signatures. Practical examples including RSA, DES. Analysis of the effectiveness of algorithms and methods of attack.