Digital Communication II

Lecturer: Professor I.M. Leslie and others (iml@cl.cam.ac.uk)

No. of lectures: 12

Prerequisite course: Digital Communication I

This course is a prerequisite for Security (Part II).

Aims

This course aims to provide a detailed understanding of how (wide area) computer networks operate, and to present the issues which are involved in building such systems. It also hopes to cover a selection of topics which relate to recent trends in digital communications systems.

Note: the lecture breakdown below is from last year's course. This year's details will be available by the start of the course.

Lectures

• Review of basic principles. Abstraction, layering. Concept of channel. OSI reference model. Standards bodies. [2 lectures]

• The Internet in detail. IP addressing, header functions, routing architecture, routing protocols. [2 lectures]

• TCP in detail. TCP bandwidth usage and control, congestion, efficiency. Connection states. [2 lectures]

• Multicast. Concepts. Internet multicast model. Applications. Basic implementation. Refinements. Congestion control. [1 lecture]

• Quality of service in the Internet. Guarantees versus best effort. Flow specs. IntServ and DiffServ. RSVP. Economic models. [3 lectures]

• ATM. Architecture, motivation. Relation to packet switching, circuit switching. Quality of service considerations. Resource management. Performance quantities. VR performance, effective bandwidth. ABR strategies. [1 lecture]

• Late topics. An examination of some current issues in the Internet. [1 lecture]

Objectives

At the end of the course students should be able to

• enumerate and explain the layers of the OSI reference model

• define effective bandwidth

• describe how TCP attempts to handle congestion in the network

• compare and contrast connectionless and connection-oriented networks

• explain how IP routing works

• argue for or against the provision of Quality of Service (QoS) in the Internet

• understand the motivation behind and operation of admission control algorithms

• give a basic explanation of how the TCP protocol works

• differentiate between the IntServ and DiffServ approaches to QoS

• realise the O/S issues in supporting TCP urgent data

• compare and contrast switching and routing

Recommended books

Comer, D. & Stevens, D. (1995). Internetworking with TCP-IP, vol. 1 and 2. Prentice-Hall (3rd ed.).
Halsall, F. (1992). Data Communications, Computer Networks and Open Systems. Addison-Wesley (3rd ed.).
Schwartz, M. (1987). Telecommunication Networks: Protocols, Modeling and Analysis. Addison-Wesley.