introduction 1-1 networking admin 1 to 4 lectures a week for 11 weeks for a total of 23 lectures ...
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Introduction 1-1
Networking Admin
1 to 4 lectures a week for 11 weeks for a total of 23 lectures
Interleaves with Functional Programming
First prac this week (THU 17): then every second teaching week (5 pracs in total)
Practicals with a difference
Two weeks to ‘execute them’Self assessment They will be as last year, so you will be
able to have the solutions ahead of handing in, if you like responsibility
Well, PERSONAL RESPONSIBILITY should be the keyword of your relation with this course
It worked reasonably well last year and the year before
Introduction 1-2
The course is entirely based on a book (a very good one!) First 5 chapters (about 500 pages) Of course, some material will be left
out: altogether about 260 pages Still, 10 to 20 pages to read per lecture
(depending on difficulty) Book must be read BEFORE practicals,
though might be understood for real just after ending prac
Introduction 1-3
The book again…
Important: references in the book. Get used to that and use them (within reason)
Another important resource, of course: the internet (for example wikipedia and from there to ‘core’ documents, up to RFCs; www.networksorcery.com is a very useful resource for protocols)
Introduction 1-4
So why having lectures?
Actually not too sure: tradition? Lack of inventiveness? Because life has to be hard, as parents / teachers kept telling you? ;-)
Lectures to get your interest going, or to clarify general / difficult concepts
To ease the difficulty of self learning (which remains the best way to learn, however)
As interactive as possible, please (like, don’t fall asleep…)
Introduction 1-5
Introduction 1-6
The book (and a lot of material!)
Computer Networking: A Top Down Approach ,4th edition. Jim Kurose, Keith RossAddison-Wesley, July 2007.
A note on the use of these ppt slides:We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) in substantially unaltered form, that you mention their source (after all, we’d like people to use our book!) If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material.
Thanks and enjoy! JFK/KWR
All material copyright 1996-2007J.F Kurose and K.W. Ross, All Rights Reserved
Introduction 1-7
Chapter 1: IntroductionOur goal: get “feel” and
terminology more depth, detail
later in course approach:
use Internet as example
Overview: what’s the Internet? what’s a protocol? network edge; hosts, access
net, physical media network core: packet/circuit
switching, Internet structure performance: loss, delay,
throughput security protocol layers, service
models history
Introduction 1-8
Chapter 1: roadmap
1.1 What is the Internet?1.2 Network edge
end systems, access networks, links
1.3 Network core circuit switching, packet switching, network structure
1.4 Delay, loss and throughput in packet-switched networks
1.5 Protocol layers, service models1.6 Networks under attack: security1.7 History
Introduction 1-9
What’s the Internet: “nuts and bolts” view
millions of connected computing devices: hosts = end systems running network
apps Home network
Institutional network
Mobile network
Global ISP
Regional ISP
router
PC
server
wirelesslaptop
cellular handheld
wiredlinks
access points
communication links fiber, copper,
radio, satellite transmission
rate = bandwidth
routers: forward packets (chunks of data)
Introduction 1-10
“Cool” internet appliances
World’s smallest web serverhttp://www-ccs.cs.umass.edu/~shri/iPic.html
IP picture framehttp://www.ceiva.com/
Web-enabled toaster +weather forecaster
Internet phones
Introduction 1-11
What’s the Internet: “nuts and bolts” view protocols control sending,
receiving of msgs e.g., TCP, IP, HTTP, Skype,
Ethernet
Internet: “network of networks” loosely hierarchical public Internet versus
private intranet
Internet standards RFC: Request for comments IETF: Internet Engineering
Task Force
Home network
Institutional network
Mobile network
Global ISP
Regional ISP
Introduction 1-12
What’s the Internet: a service view communication
infrastructure enables distributed applications: Web, VoIP, email, games,
e-commerce, file sharing communication services
provided to apps: reliable data delivery
from source to destination
“best effort” (unreliable) data delivery
Introduction 1-13
What’s a protocol?human protocols: “what’s the time?” “I have a question” introductions
… specific msgs sent… specific actions
taken when msgs received, or other events
network protocols: machines rather than
humans all communication
activity in Internet governed by protocols
protocols define format, order of msgs sent and
received among network entities, and actions taken on msg transmission, receipt
Introduction 1-14
What’s a protocol?a human protocol and a computer network protocol:
Q: Other human protocols?
Hi
Hi
Got thetime?
2:00
TCP connection request
TCP connectionresponseGet http://www.awl.com/kurose-ross
<file>time
Introduction 1-15
Chapter 1: roadmap
1.1 What is the Internet?1.2 Network edge
end systems, access networks, links
1.3 Network core circuit switching, packet switching, network structure
1.4 Delay, loss and throughput in packet-switched networks
1.5 Protocol layers, service models1.6 Networks under attack: security1.7 History
Introduction 1-16
A closer look at network structure:
network edge: applications and hosts
access networks, physical media: wired, wireless communication links network core: interconnected
routers network of
networks
Introduction 1-17
The network edge: end systems (hosts):
run application programs e.g. Web, email at “edge of network”
client/server
peer-peer
client/server model client host requests,
receives service from always-on server
e.g. Web browser/server; email client/server peer-peer model:
minimal (or no) use of dedicated servers
e.g. Skype, BitTorrent