Lecture E-Commerce - Chapter 4: The internet and the web (part II)

In this chapter, the learning objectives are: Explain the current structure of internet, understand the limitations of todays internet, describe the potential capabilities of internet II, understand how the world wide web works, describe how internet and web features and services support e-commerce.

CSC 330 E-Commerce

Teacher

Ahmed Mumtaz Mustehsan

GM-IT CIIT Islamabad

• Virtual Campus, CIIT

• COMSATS Institute of Information Technology

• T1-Lecture-4

The Internet and The Web

Chapter-2 Part-II

T1-Lecture-4

For Lecture Material/Slides Thanks to:

Copyright © 2010 Pearson Education, Inc

 Explain the current structure of Internet.

 Understand the limitations of todays internet

 Describe the potential capabilities of Internet II

 Understand how the world wide web works

 Describe how internet and web features and services support e-commerce.

The Hourglass Model of the Internet

SOURCE: Adapted from Computer

Science and Telecommunications

Board (CSTB), 2000.

The Hourglass Model of the Internet

 The Internet can be characterized as an hour-glass modular structure with a lower layer containing the bit- carrying infrastructure (including cables and switches) and an upper layer containing user applications such

as e-mail and the Web

 In the narrow waist are transportation protocols such

as TCP/IP.

Network Technology Substrate layer

 Layer-1 of Internet technology that is composed of

telecommunications networks and protocols

Transport Services and Representation Standards layer

 Layer-2 of Internet architecture that houses the

TCP/IP protocol

The Hourglass Model of the Internet

Middleware Services layer

Layer-3: The “glue” that ties the applications to the

communications networks, and includes such services as security, authentication, addresses, and storage

repositories.

Applications layer

Layer-4 of Internet architecture that contains client

applications; such as World Wide Web, e-mail, and

audio or video playback.

Internet Network Architecture

Metropolitan Area Exchanges (MAEs), Network Access Points (NAPs)

Internet Network Architecture Concepts

Backbone:

◦High-bandwidth fiber-optic cable networks

◦Private networks owned by a variety of Network Service

Providers (NSPs)

◦Bandwidth: 155 Mbps 2.5 Gbps

◦Built-in redundancy

Network Service Provider (NSP)

Owns and controls one of the major networks comprising the

Internet’s backbone

Bandwidth

measures how much data can be transferred over a communications medium within a fixed period of time; is usually expressed in bits per second (bps), kilobits per second (Kbps), megabits per second

(Mbps),or gigabits per second (Gbps)

Redundancy

Multiple duplicate devices and paths in a network

Internet Exchange Points (IXPs)

Hubs where backbones intersect with regional and local networks, and backbone owners connect with one another (older term NAPS)

Campus area networks (CANs)

LANs operating within a single organization that leases Internet access directly from regional or national carrier such as New York University or Microsoft Corporation

Internet Network Architecture Concepts

Internet Service Providers (ISPs)

Provide lowest level of service to individuals, small

businesses, some institutions

acceptable speed generally anything above 100 Kbps.

Digital Subscriber Line (DSL)

a telephone technology for delivering high-speed

access through ordinary telephone lines found in homes

or businesses

1-Internet Network Architecture Concepts

Cable modem

A cable television technology that piggybacks digital access to the Internet on top of the analog video cable providing television signals to a home

T1 Line

 an international telephone standard for digital

communication that offers guaranteed delivery at 1.54 Mbps

T3

 an international telephone standard for digital

communication that offers guaranteed delivery at 45

Intranets and Extranets

Intranet (Internal network)

A TCP/IP network located within a single

organization for purposes of communications and

information processing e.g Intranet of CIIT

Extranet (external network)

Formed when firms permit outsiders to access their internal TCP/IP networks e.g General Motors

permits parts suppliers to gain access to GM’s

intranet

Note:

Intranets and extranets generally do not involve commercial

transactions in a marketplace, however, extranets supports

certain types of B2B exchanges

1-Who Governs the Internet?

Promoters of internet claim that no one governs internet as it is

public domain and inherently above and beyond the law

However, there are certain organization that influence Internet and monitor its operations such as :

Internet Architecture Board (IAB)

Internet Corporation for Assigned Names and

Numbers (ICANN)

Internet Engineering Steering Group (IESG)

Internet Engineering Task Force (IETF)

Internet Society (ISOC)

World Wide Web Consortium (W3C)

International Telecommunications Union (ITU)

1-Limitations of current Internet Infrastructure

Bandwidth limitations: Backbone, MAN,CAN & last-mile

Quality of service limitations

Latency : delays in messages caused by the uneven flow of

information packets through the network

“best-effort” quality of service (QoS), which makes no

guarantees about when or whether data will be delivered,

Network architecture limitations

Downloading same music by thousands of clients slows down

network performance as the same music track is sent out a

thousand times to clients that might be located in the same

metropolitan area

Language development limitations

HTML, the language of Web pages, is fine for text and simple

graphics, but poor at defining and communicating “rich

documents,” such as databases, business documents, or

graphics

Wired Internet limitations

Copper cables use a old technology, and fiber-optic cable is

expensive to place underground The wired nature of the Internet restricts mobility of users as compared to wifi

T1-Lecture-4 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc 14

1-The Internet2® Project

 Consortium of 200+ universities, government agencies, and

private businesses collaborating to find ways to make the Internet more efficient, faster, reliable and affordable

 GigaPoP : a regional Gigabit Point of Presence, or point of

access to the Internet2 network, that supports at least one gigabit (1 billion bits) per second information transfer

Primary goals:

 Create leading edge very-high speed network for national

research community

 Enable revolutionary Internet applications

 Ensure rapid transfer of new network services and applications to broader Internet community

1-The Larger Internet II Technology Environment:

GENI Initiative

Global Environment for Networking Innovations (GENI) Initiative

to develop new core functionality for the Internet, including new

naming, addressing and identity architectures;

enhanced capabilities, including additional security architecture and a design that supports high availability;

new Internet services and applications

Proposed by NSF

to develop new core functionality for Internet

Most significant private initiatives (Fiber-Optic and Wireless)

Fiber optics is concerned with the first mile or backbone Internet services that carry bulk traffic long distances

Wireless Internet is concerned with the last mile from the larger Internet to the user’s cell phone or laptop Mobile wireless Internet services

1-Fiber Optics and the Bandwidth Explosion in the First Mile

◦ Photonic technologies expand capacity of existing fiber lines

1-Optical Fiber

1-Optical Fiber

Source: Adapted from Panko, Raymond, Business Data Communications and Networking (3 rd  ed.), Upper 

Saddle River, NJ: Prentice­Hall, 2001, p. 278.

1-Mobile Wireless Internet Access: The Last Mile:

“Last mile”:

From Internet backbone to user’s computer, cell

phone, PDA, etc

Two different basic types of wireless Internet

1-Telephone-based Wireless Internet Access

(2G) Second generation cellular networks

transmit data at about 10 Kbps

(2.5G)

(2.5G) network interim cellular network

Radio Services (GPRS)

technology carries data in packets, just like the Internet, but over radio frequencies that make wireless communication

possible.

(3G)

cellular phone standards that can connect users to the Web

1-Telephone-based Wireless Internet Access

communications system widely used in Europe and Asia that uses narrowband Time Division Multiple Access (TDMA)

communications system widely used in the United States that uses the full spectrum of radio frequencies and digitally

encrypts each call

(4 G) Fourth Generation: (LTE and WiMax )

Long Term Evolution:

WiMax

Mbps.

1-Wireless Local Area Networks (WLANs)

Wi-Fi

High-speed, fixed broadband wireless LAN, different versions

for home and business market, limited range

 Short-range, low-power wireless network technology for

remotely controlling digital devices

1-Wi-Fi Networks