Digital Communication II

Lecturers: Dr I.A. Pratt, Prof. J.A. Crowcroft and guests
(ian.pratt@cl.cam.ac.uk, jon.crowcroft@cl.cam.ac.uk)

No. of lectures and examples classes: 20 + 4

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 computer networks operate, through the examples of the Internet, and presents ways to build such systems. It also covers a selection of topics which relate to recent trends in digital communications systems. The material falls roughly into two halves: Protocols, and Technologies.

Lectures

• Introduction. Course overview. Abstraction, layering. The OSI reference model. [IAP/JAC]

• The Internet: IP. IP overview/review. Networking in Unix: structures, buffering, sockets, network interfaces. IP addresses and (simple) routing. Subnetting. IP checksum. Fragmentation. [JAC]

• The Internet: routing. ROADS and CIDR. Terminology: AS, IGP, EGP. Routing protocols: distance vector versus link state. Examples: RIP, OSPF. AS routing: I-BGP/E-BGP, metrics. [JAC, 2 lectures]

• The Internet: network resource management. Differentiated and integrated services. Signalling (RSVP) and admission control, forwarding and scheduling, policing and shaping. The future. [JAC, 2 lectures]

• The Internet: multicast and QoS routing. Other TCP details. Internet multicast model. Applications. Basic implementation. Refinements. [JAC, 2 lectures]

• The Internet: UDP, TCP. TCP operation, state transitions. Handling loss: acks and retransmissions. Estimating RTT. Basic congestion control. Improving things: TCP vegas, SACKs, ECN. [JAC, 2 lectures]

• The Internet: applications, multimedia, NFS & HTTP. RTP operation, playout adaption; RPC & network file systems; HTTP, HTTP 1.1 - making it all work [JAC/IAP, 2 lectures]

• The Internet: IPv6. Concepts. Internet multicast model. Applications. Basic implementation. Refinements. Congestion control. [RJB]

• ATM case study. Multiplexing and virtual circuits. Signalling. ATM adaption layers. Quality of service CBR, VBR, ABR. [IAP, 2 lectures]

• Wide area networks. Fibre technology. Long-haul link design. Dense wave division multiplexing. Sonet/SDH. MPLS. Packet over SONET. Optical switching. [IAP]

• Access networks. Cable modems. xDSL. Fixed wireless. Satellite. Firewalls and network address translation. [IAP]

• Local area networks and system area networks. Fast/Gigabit Ethernet. Optimising latency. Host interface design. User-space protocol processing. [IAP]

• Congestion pricing. Model and motivation. Practical considerations. The future. [DRM]

• Additional Topics. To be announced. [IAP+]

Objectives

At the end of the course students should be able to

• enumerate and explain the layers of the OSI reference model

• compare and contrast connectionless and connection-oriented networks

• explain how IP routing works

• describe the components of the Internet resource management system

• describe how and why TCP attempts to handle congestion in the network

Recommended books

Keshav, S. (1997). An Engineering Approach to Computer Networking. Addison-Wesley (1st ed.). ISBN: 0201634422

Alternative to Keshav:
Davie, B.S., Peterson, L.L. & Clark, D. (1999). Computer Networks: A Systems Approach. Morgan Kaufmann (2nd ed.). ISBN: 1558605142

Stevens, W.R. (1994). TCP/IP Illustrated, Volume 1: The Protocols. Addison-Wesley (1st ed.). ISBN: 0201633469

Alternative to Stevens:
Comer, D. (2000). Internetworking with TCP/IP Vol. I: Principles, Protocols, and Architecture. Prentice Hall (4th ed.). ISBN: 0130183806

Background:
Krishnamurthy, B. & Rexford, J. (2001). Web Protocols and Practice: HTTP/1.1, Networking Protocols, Caching, and Traffic Measurement. Addison-Wesley (1st ed.). ISBN: 0201710889