G52CCN
Computer Communications
and Networks
Milena Radenkovic
Milena Radenkovic
Room: B47
Room: B47
Email: [email protected]
Introduction
Practical mattersPractical matters
Module goals, structure and contentsModule goals, structure and contents
Initial introduction to some key ideas and Initial introduction to some key ideas and
issues
Lectures
Monday,11:00Monday,11:00
Related modules
G53ACC - Advanced Computer G53ACC - Advanced Computer
Communications
Communications
G5BIAW - The Internet and the World Wide G5BIAW - The Internet and the World Wide
Web
Objectives
To understand the basic principles of data To understand the basic principles of data
communications and computer networks. communications and computer networks.
To appreciate the complex trade-offs that are To appreciate the complex trade-offs that are
inherent in the design of networks. inherent in the design of networks.
To provide a guided tour of network technologies To provide a guided tour of network technologies
from the lowest levels of data transmission up to from the lowest levels of data transmission up to
network applications. network applications.
To learn about current networking technologies, To learn about current networking technologies,
Assessment
Two hour written examination Two hour written examination
The style of question will be based upon those The style of question will be based upon those
from previous years. Their content will of course from previous years. Their content will of course
be different. be different.
Last year’s exam paper is on sale in the bookshop Last year’s exam paper is on sale in the bookshop
and previous papers are in the library. and previous papers are in the library.
Text books and notes
My notes are available at:My notes are available at:
http://www.cs.nott.ac.uk/~mvr/ccnhttp://www.cs.nott.ac.uk/~mvr/ccn
The core recommended course text is:The core recommended course text is:
Computer Networks and Internets, Douglas E. Comer, Computer Networks and Internets, Douglas E. Comer, Prentice Hall
Prentice Hall
Supplementary texts are:Supplementary texts are:
Tannenbaum, Computer Networks, Prentice HallTannenbaum, Computer Networks, Prentice Hall
What is a computer network?
An interconnection of An interconnection of autonomousautonomous
computers (as opposed to communication
computers (as opposed to communication
between separate but interdependent parts
between separate but interdependent parts
of a single computer)
Some goals of computer networks
Access to remote resourcesAccess to remote resources Human communicationHuman communication
Mobile computingMobile computing
Computing power through parallelismComputing power through parallelism Optimising resources - load balancingOptimising resources - load balancing
Incremental growth of computer systems (reduced Incremental growth of computer systems (reduced
cost and risk) cost and risk)
Uses of computer networks
Email, World Wide Web, Video Email, World Wide Web, Video
Conferencing, File Transfer, Collaborative
Conferencing, File Transfer, Collaborative
Virtual Environments, Remote control of
Virtual Environments, Remote control of
robots and machines, Dial up databases,
robots and machines, Dial up databases,
Webcasting, Distributed Programs,
Webcasting, Distributed Programs,
Hacking, Banking, Internet telephone
Classifying networks
By sizeBy size
Local area networks (LANs) versus Wide area Local area networks (LANs) versus Wide area
networks (WANs) networks (WANs)
By connectivityBy connectivity
Point to point versus broadcast networksPoint to point versus broadcast networks
By communication mediumBy communication medium By mobilityBy mobility
Size - differences between local
and wide area networks
‘‘Speed’ - bandwidth and latencySpeed’ - bandwidth and latency
ManagementManagement
SecuritySecurity
ReliabilityReliability
BillingBilling
Connectivity - point to point
networks
star
tree
irregular
Connectivity - broadcast
networks
Medium - differences between
communication media
‘‘Speed’ - bandwidth and latencySpeed’ - bandwidth and latency
RangeRange
SharingSharing
TopologyTopology
Installation and maintenance costsInstallation and maintenance costs
Mobility - issues arising in
mobile networks
Mobile networking has emerged in the last Mobile networking has emerged in the last
decade. Introduces new issues of:
decade. Introduces new issues of:
energy efficiencyenergy efficiency
location and trackinglocation and tracking
semi-persistent connectionssemi-persistent connections
complex administration and billing as complex administration and billing as devices and users move around the
devices and users move around the
network
Common issues in networking
AddressingAddressing
RoutingRouting
Framing and encodingFraming and encoding
Error detection and correctionError detection and correction
Module contents and structure
Part 1: data transmission
Part 2: packet transmission
Part 1: data transmission
Transmission media; Transmission media;
Local asynchronous communication (RS-232); Local asynchronous communication (RS-232);
Long distance communication (modems and Long distance communication (modems and
Part 2: packet transmission
Packets, frames and error detectionPackets, frames and error detection Local area networks (LANs)Local area networks (LANs)
Hardware addressingHardware addressing
LAN wiring and physical topologyLAN wiring and physical topology
Extending LANS: Fiber Modems, repeaters, Extending LANS: Fiber Modems, repeaters,
bridges and switches;
bridges and switches;
WAN Technologies and routingWAN Technologies and routing
Part 3: internetworking
Concepts, architecture and protocolsConcepts, architecture and protocols IP addressesIP addresses
Binding protocol addresses (ARP)Binding protocol addresses (ARP)
IP Datagrams and datagram forwardingIP Datagrams and datagram forwarding
IP encapsulations, fragmentation and reassemblyIP encapsulations, fragmentation and reassembly The future of IPThe future of IP
Part 4: applications
Client-server interactionClient-server interaction
The socket interfaceThe socket interface
