Ch1 - EEE 459 C m om unication Ne tworks S pring 2007 Prof...

Introduction 1-1
EEE 459 Communication
Networks
Spring 2007
Prof. M. Reisslein
Chapter 1
Introduction
Textbook:
Computer Networking: A Top
Down Approach Featuring the
Internet,
3
rd
edition.
Jim Kurose, Keith Ross
Addison-Wesley.

Introduction 1-2
Chapter 1: Introduction
Our goal:
 get “feel” and terminology
 moredepth, detail later in
course
 approach:
❍
useInternet as example
Overview:
 what’s theInternet
 what’s a protocol?
 network edge
 network core
 access net, physical media
 Internet/ISP structure
 performance: loss, delay
 protocol layers, servicemodels
 network modeling

Introduction 1-3
Chapter 1: roadmap
1.1 What is theInternet?
1.2 Network edge
1.3 Network core
1.4 Network access and physical media
1.5 Internet structureand ISPs
1.6 Delay & loss in packet-switched networks
1.7 Protocol layers, servicemodels
1.8 History

Introduction 1-4
What’s the Internet: “nuts and bolts” view
 millions of connected computing
devices: hosts = end systems
 running network apps
 communication links
❍
fiber, copper, radio, satellite
❍
transmission rate = bandwidth
 routers: forward packets (chunks
of data)
local ISP
company
network
regional ISP
router
workstation
server
mobile

Introduction 1-5
What’s the Internet: “nuts and bolts” view

protocols control sending, receiving
of msgs
❍
e.g., TCP, IP, HTTP, FTP, PPP
 Internet: “network of networks”
❍
loosely hierarchical
❍
public Internet versus private intranet
 Internet standards
❍
RFC: Request for comments
❍
IETF: Internet Engineering Task
Force
local ISP
company
network
regional ISP
router
workstation
server
mobile

Introduction 1-6
What’s the Internet: a service view
 communication infrastructure
enables distributed applications:
❍
Web, email, games, e-commerce, file
sharing
 communication services provided
to apps:
❍
Connectionless unreliable
❍
connection-oriented reliable

Introduction 1-7
What’s a protocol?
human protocols:

“what’s thetime?”
 “I havea 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 1-8
What’s a protocol?
a human protocol and a computer network protocol:
Q: Other human protocols?
Hi
Hi
Got the
time?
2:00
TCP connection
req
TCP connection
response
Get http://www.awl.com/kurose-ross
<file>
time

Introduction 1-9
Chapter 1: roadmap
1.1 What is theInternet?
1.2 Network edge
1.3 Network core
1.4 Network access and physical media
1.5 Internet structureand ISPs
1.6 Delay & loss in packet-switched networks
1.7 Protocol layers, servicemodels
1.8 History

Introduction 1-10
A closer look at network structure:
 network edge:
applications and hosts
 network core:
❍
routers
❍
network of networks
 access networks, physical
media: communication
links