Chapter 1 v7 01

Lai NGUYEN
Research & Interests

â1996-2016, J.F Kurose and K.W. Ross

ã Distributed systems: Analysis, optimization, and control of
systems with limited communication.
• Communication networks and protocols: Network
architecture, routing algorithms, protocols, applications, and
services. Network design, measurement, analysis, optimization,
and management.

▪ Areas of specialty
• Networked dynamic systems, distributed cooperative control, network
routing, constrained communication protocols, water systems.

▪ Contact
• Office: Faculty of Computer Science and Engineering
▪ Block A3, Ho Chi Minh City University of Technology

• Email:


©1996-2016, J.F Kurose and K.W. Ross

Computer Networks
Lectured by:
Nguyen Le Duy Lai
()

Computer

Networking: A Top
Down Approach
7th Edition, Global Edition
Jim Kurose, Keith Ross
Pearson
April 2016
Introduction

1-2


Course details
Credits

3 (3.2.7)

Credits Hours

Total:
75

Lecture:
42

Exercise:

Lab:

©1996-2016, J.F Kurose and K.W. Ross

Evaluation
Assessment method

Midterm:

10%

Code

CO3003

Lab:
22

Assignments:
11

Assignments: Final exam:

30%

60%

Final exam: Multiple choice questions, ~ 90 minutes
Laboratory work is compulsory (No lab work = No assignment mark)

Prerequisites
Co-requisites

Undergraduate Programs Computer Science and Computer Engineering

Website

/>3


Course outline (1)
▪ Fundamental concepts in the design and
implementation of computer networks

â1996-2016, J.F Kurose and K.W. Ross

ã Protocols, standards, services and applications
• Introduction to network programming
• Basic network security

▪ The goals of the course are to build on basic
networking knowledge in providing …
• an understanding of the tradeoffs and existing
technology used in complex networked systems
• concrete experience of the challenges through a series
of lab exercises.
4


Course outline (2)

©1996-2016, J.F Kurose and K.W. Ross

▪ The topics to be covered include:
• Introduction to network architecture, OSI and TCP/IP

reference models.
• Common applications and application layer protocols: Web
(HTTP), DNS, E-mail (POP3, IMAP, SMTP), P2P, and CDN.
• Internet transport protocols (UDP and TCP)
• Issues related to routing and internetworking, Internet
addressing, routing protocols and Internet Protocol (IP).
• Network technologies, especially LAN technologies (Ethernet,
wireless networks and Bluetooth).
• Network-programming interface
• Network security
5


©1996-2016, J.F Kurose and K.W. Ross

Contents
▪
▪
▪
▪
▪
▪
▪
▪
▪

Computer Networks and the Internet
Application Layer
Transport Layer
The Network Layer: Data Plane

The Network Layer: Control Plane
The Link Layer and LANs
Wireless and Mobile Networks
Security in Computer Networks
Multimedia Networking
Introduction

2-6


References
▪ “Computer Networking: A Top Down Approach”,
Jim Kurose, Keith Ross, 7th Global Edition, Pearson,
2016.

©1996-2016, J.F Kurose and K.W. Ross

▪ “The Illustrated Network: How TCP/IP Works in
a Modern Network”, Walter Goralski, Second Edition,
Morgan Kaufman, 2017.
▪ “Computer Networks”, Andrew S. Tanenbaum, David J.
Wetherall, 5th Edition, Prentice Hall, 2012.

7


©1996-2016, J.F Kurose and K.W. Ross

Chapter 1
Introduction

Computer
Networking: A Top
Down Approach
7th Edition, Global Edition
Jim Kurose, Keith Ross
Pearson
April 2016
Introduction

1-8


©1996-2016, J.F Kurose and K.W. Ross

Chapter 1: introduction
our 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

1-9


Chapter 1: roadmap
1.1 what is the Internet?
1.2 network edge
▪ end systems, access networks, links

1.3 network core
©1996-2016, J.F Kurose and K.W. Ross

▪ packet switching, circuit switching, network structure

1.4 delay, loss, throughput in networks
1.5 protocol layers, service models
1.6 networks under attack: security
1.7 history

Introduction

1-10

What’s the Internet: “nuts and bolts” view
▪ billions of connected
server
computing devices:
wireless
ã hosts = end systems
laptop
ã running network apps
smartphone

â1996-2016, J.F Kurose and K.W. Ross

PC

▪ communication links
• media: fiber, copper,
wireless
links
radio, satellite
wired
• transmission rate:
links
bandwidth

router

▪ packet switches: forward
packets (chunks of data)

• routers and switches

mobile network
global ISP

home
network
regional ISP

institutional
network
Introduction

1-11


“Fun” Internet-connected devices
Web-enabled toaster +
weather forecaster

©1996-2016, J.F Kurose and K.W. Ross

IP picture frame
/>
Slingbox: watch,
control cable TV remotely

Internet
refrigerator

Tweet-a-watt:
monitor energy use

sensorized,
bed
mattress
Internet phones
Introduction

1-12


What’s the Internet: “nuts and bolts” view
▪ Internet: “network of networks”

mobile network

• Interconnected ISPs

global ISP

▪ Protocols: control sending, receiving
of messages
• e.g., TCP, IP, HTTP, Skype, 802.11

©1996-2016, J.F Kurose and K.W. Ross

▪ Internet standards

home

network
regional ISP

• RFC: Request for comments
• IETF: Internet Engineering Task Force

institutional
network
Introduction

1-13


What’s the Internet: a service view
▪ infrastructure that provides
services to applications
ã Web, VoIP, email, games, ecommerce, social nets,

â1996-2016, J.F Kurose and K.W. Ross

▪ provides programming
interface to apps

mobile network
global ISP

home
network
regional ISP

• hooks that allow sending
and receiving app programs
to “connect” to Internet
• provides service options,
analogous to postal service
institutional
network
Introduction

1-14


©1996-2016, J.F Kurose and K.W. Ross

What’s a protocol?
human protocols:

network protocols:

▪ “what’s the time?”
▪ “I have a question”
▪ introductions

▪ machines rather than
humans
▪ all communication activity
in Internet governed by
protocols

… specific messages sent

… specific actions taken
when messages
received, or other
events

protocols define format, order of
messages sent and received
among network entities, and
actions taken on message
transmission, reception
Introduction

1-15


What’s a protocol?
a human protocol and a computer network protocol:
Hi

TCP connection
request

©1996-2016, J.F Kurose and K.W. Ross

Hi

TCP connection
response

Got the

time?

Get />
2:00

<file>
time

Q: other human protocols? A: ?
Introduction

1-16


Chapter 1: roadmap
1.1 what is the Internet?
1.2 network edge
▪ end systems, access networks, links

1.3 network core
©1996-2016, J.F Kurose and K.W. Ross

▪ packet switching, circuit switching, network structure

1.4 delay, loss, throughput in networks
1.5 protocol layers, service models
1.6 networks under attack: security
1.7 history

Introduction

1-17


A closer look at network structure:
▪ network edge

mobile network

• hosts: clients and servers

global ISP

ã servers often in data
centers

â1996-2016, J.F Kurose and K.W. Ross

▪ access to networks,
physical media

home
network
regional ISP

▪ wired, wireless
communication links

▪ network core
• interconnected routers

• network of networks

institutional
network
Introduction

1-18


Access networks and physical media
Q: How to connect end
systems to edge router?

©1996-2016, J.F Kurose and K.W. Ross

▪ residential access networks
▪ institutional access networks
(e.g., school, company)
▪ mobile access networks

keep in mind:
▪ bandwidth (bits per second bps) of access network?
▪ shared or dedicated?

Introduction

1-19


Access network: digital subscriber line (DSL)

central office

©1996-2016, J.F Kurose and K.W. Ross

DSL splitter
modem

voice, data transmitted
at different frequencies over
dedicated line to central office

telephone
network

DSLAM

ISP
DSL access
multiplexer

▪ use existing telephone line to central office DSLAM
• data over DSL phone line goes to Internet
• voice over DSL phone line goes to telephone network
▪ < 2.5Mbps upstream transmission rate (typically < 1Mbps)
▪ < 24Mbps downstream transmission rate (typically < 10Mbps)
Introduction

1-20

Access network: cable network
cable headend

…

©1996-2016, J.F Kurose and K.W. Ross

cable splitter
modem

V
I
D
E
O

V
I
D
E
O

V
I
D
E
O

V
I

D
E
O

V
I
D
E
O

V
I
D
E
O

D
A
T
A

D
A
T
A

C
O
N
T

R
O
L

1

2

3

4

5

6

7

8

9

Channels

frequency division multiplexing: different channels transmitted
in different frequency bands
Introduction

1-21

Access network: cable network
cable headend

…
cable splitter
modem

data and TV transmitted at different

©1996-2016, J.F Kurose and K.W. Ross

frequencies over shared cable
distribution network

CMTS

cable modem
termination system

ISP

▪ HFC: hybrid fiber coax
• asymmetric: up to 30Mbps downstream transmission rate,
2Mbps upstream transmission rate
▪ network of cable, fiber attaches homes to ISP router
• homes shared access network to cable headend
• unlike DSL, which has dedicated access to central office
Introduction

1-22


Access network: home network
wireless
devices

©1996-2016, J.F Kurose and K.W. Ross

to/from headend or
central office
often combined
in single box

cable or DSL modem
wireless access
point (54 Mbps)

router, firewall, NAT
wired Ethernet (1 Gbps)
Introduction

1-23


Enterprise access networks (Ethernet)

institutional link to
ISP (Internet)

©1996-2016, J.F Kurose and K.W. Ross

institutional router

Ethernet
switch

institutional mail,
web servers

▪ typically used in companies, universities, etc.
▪ 10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps transmission rates
▪ today, end systems typically connect into Ethernet switch
Introduction

1-24


Wireless access networks
▪ shared wireless access network connects end system to router
• via base station aka “access point”

wide-area wireless access

wireless LANs:

©1996-2016, J.F Kurose and K.W. Ross

▪ within building (100 ft.)
▪ 802.11b/g/n/ac (Wi-Fi): transmission

rate 11/54/450/1000 Mbps

to Internet

▪ provided by telco (cellular)
operator, 10’s km
▪ between 1 and 10 Mbps
▪ 3G, 4G (LTE), 5G

to Internet
Introduction

1-25