internet architecture

Internet Architecture
2
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Day 8 Agenda

Return and review assignment # 2

5 A’s, 3 B’s, 1 D, 2 non-submits

Quiz # 1 on Oct 4

Chap 1, 2 & 3

20 M/C, 1 Essay (choice of 3), 1 Extra
credit

45 Min Open Book Open Notes

Lecture/Discuss Internet Architecture
3
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Overview

What is a Network?

IP Addresses

Networks


Information Transfer

Cable Types

Key Components of a Network

Factors in Designing a Network

Network Management System
Internet Architecture
4
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
What is a Network?

A connection between at least two
computers for the purpose of sharing
resources

Types:

Local Area Networks (LANs)

Wide Area Networks (WANs)

Metropolitan Area Networks (MANs)
Internet Architecture: What is a Network?
5
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall

Peer-to-peer Network

Computers linked together as equals

No centralized control

Share resources on the same network
in any way & any time

Promotes institutionalized chaos

< 10 computers
Internet Architecture: What is a Network?
6
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Peer-to-peer Network (Cont’d)

Benefits

Easy to install/configure

Inexpensive

User is able to control
their own resources

Independent from a
dedicated server


No need for a network
administrator

Drawbacks

Security problems

Performance suffers when
a computer is accessed

Difficult to have backup

Decentralized logon
passwords

No centralized data
management
Internet Architecture: What is a Network?
7
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Client/Server Network

Server – designed to address a client’s
request

Client – any computer connected to the
server within a network

Allow authorized user to access any

programs/application resided on the server
Internet Architecture: What is a Network?
8
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Client/Server Network (Cont’d)

Benefits

Centralized security
control

Simpler network
administration than peer-
to-peer network

Centralized password

More scalable

Ideal for computers are
apart

Drawbacks

Network failure = clients
are helpless

Specialized staff are
needed


Higher costs
Internet Architecture: What is a Network?
9
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
IP Addresses

A host number to identify itself to other
hosts

Consists of strings of 32 bits

E.g.
10111111010101010100000000001100
= 191.170.64.12

Host Name

Human-friendly internet addresses

E.g. ema3z.mcintire.virginia.edu
Internet Architecture: IP Addresses
10
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Networks

Network vs. Local


Networks are classified by three sizes:
Internet Architecture: Networks
Class Beginning Bit Bits in
remainder
of network
part
# of bits in
local part
Max. # of
networks
Max. # of
hosts in
network
A 0 (1-127) 7 24 136 16 million
B 10(128-191) 14 16 16,000 65,000
C 110(192-223) 21 8 2 million 254
11
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Numbers of Hosts

    
#ofnetworks 
#Hosts/
network  total
ClassA 126 16,777,214 2,113,928,964
ClassB 16,382 65,534 1,073,577,988
ClassC 2,097,150 254 532,676,100

 3,720,183,052

12
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Networks (Cont’d)

Zones

Three-letter kind (com, gov, edu)

Two-letter kind (ca, uk, jp)

New general-purpose zones (firm, store)

More Information at The Inte r ne t
AssignedN umbe r sAuthority

/>Internet Architecture: Networks
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Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Network Names (TLDs)

AERO air-transport industry

ARPA Address and Routing Parameter Area

BIZ business

COM commercial


COOP cooperatives

EDU U.S. educational

GOV U.S. government

INFO information

INT international organizations

MIL U.S. military

MUSEUM museums

NAME individuals, by name

NET network ORG organization

PRO professions
14
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Day 9 Agenda

Quick Review

Quiz # 1 Today

20 M/C, 1 Essay (choice of 3), 1 Extra credit


45 Min Open Book Open Notes

Lecture/Discuss Internet Architecture

Assignment # 3

Do even numbered Review Question on Page 125
& 126 (2, 4, 6, …20)

Turn in a well formatted typed response sheet

Due Tuesday, October 8 at start of class
15
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Day 10 Agenda

Get Assignment # 3

Return and Review Quiz

2 A’s, 2 B’s, 6 C’s, 1 F

Finish Discussion on Chap 4

Next Class we will discus Case Study
and Initiative papers.
16
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall

Information Transfer

Packet

Grouping of data for transmission on a
network

Large messages are split into a series of
packets for transmission

Protocol

A rule governing how communication
should be conducted

Internet Protocol

Set of rules used to pass packets
Internet Architecture: Information Transfer
17
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Information Transfer (Cont’d)

Open Systems Interconnection (OSI)

A layered approach to networking

Each layer handles a different portion of
the communication process

Internet Architecture: Information Transfer
18
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model
Internet Architecture: Information Transfer
Layer Info Transacted TCP/IP Protocols
Application Application messages HTTP, FTP,
SNMP
Presentation Compressed data
Session Session messages
Transport Multiple packets TCP
Network Packets IP
Data Link Frames Ethernet, PPP
Physical Bits Wiring, cables
19
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model (Cont’d)

Application Layer

Defines requests & response formats

Standard: HTTP

Governs requests & response between browser
& web server application program

Other standards: SMTP, POP


HTML-compatible

File Transfer Protocol (FTP), Simple
Network Management Protocol (SNMP),
Domain Name Service (DNS)
Internet Architecture: Information Transfer
20
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model (Cont’d)

Presentation Layer

Converts data into a format the receiving
application can understand

Session Layer

Exchanges data for the duration of session

Keeps track of the status of exchange

Ensures only designated parties are
allowed to participate in the session

Enforces security protocols for controlling
access
Internet Architecture: Information Transfer
21

Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model (Cont’d)

Transport Layer

Manages the transmission of data across a
network

Transmission Control Protocol (TCP)

Specifies how two host computers will work
together

Flow control

Sequence assurance

Reliability & integrity
Internet Architecture: Information Transfer
22
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model (Cont’d)

Internet Layer

Routes messages across multiple nodes
for delivery


Handles network congestion to minimize
performance problems

Internet Protocol (IP)

Standard for routing packets
Internet Architecture: Information Transfer
23
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
OSI Reference Model (Cont’d)

Data Link Layer

Packages data into frames for delivery

Point-to-point (PPP)

Framing – mark boundary between packets

Error detection

Ethernet

Physical Layer

Converts bits into signals for outgoing
messages & signals into bits for incoming
messages
Internet Architecture: Information Transfer

24
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
Cable Types

Twisted-Pair Cable

Unshielded Twisted Pair (UTP)

Shielded Twisted Pair (STP)

Optical Fiber

Coaxial Cable

Wireless Technology
Internet Architecture: Cable Types
25
Awad –Electronic Commerce 1/e
© 2002 Prentice Hall
UTP Cable