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Telecommunications and Networks

Business value of networksThe Internet

Network components

Chapter

6

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Learning Objectives

1. Understand the concept of a network.2. Apply Metcalfe’s law in understanding the

value of a network.3. Identify several major developments and

trends in the industries, technologies, and business applications of telecommunications and Internet technologies.

4. Provide examples of the business value of Internet, intranet, and extranet applications.

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Learning Objectives

5. Identify the basic components, functions, and types of telecommunications networks used in business.

6. Explain the functions of major components of telecommunications network hardware, software, media, and services.

7. Explain the concept of client/server networking.8. Understand the two forms of peer-to-peer

networking.9. Explain the difference between digital and

analog signals.

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Learning Objectives

10. Identify the various transmission media and

topologies used in telecommunications

networks.

11. Understand the fundamentals of wireless

network technologies.

12. Explain the concepts behind TCP/IP.

13. Understand the seven layers of the OSI network

model.

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Case 1: Wireless, Wireless Everywhere

Wireless sensor devices or motes

Package together a circuit board, software,

sensors and wireless radio

Uses mesh networking software to transmit data

from one mote to another

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Case Study Questions

1. What are some of the business benefits associated with using wireless networks to collect and transmit data?

2. What are some of the challenges being faced in this use of wireless technologies? What solutions can you offer?

3. The use of wireless networking as described in the case is both innovative and useful. What other business uses can you envision for this approach?

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Real World Internet Activity

1. The companies mentioned in this case, Intel,

IBM, SAIC, and GE are all familiar names

often associated with innovative approaches

to technology. Using the Internet,

See if you can find examples of other

companies that have found ways in which to

apply mote wireless technology to business

needs.

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Real World Group Activity

One way of describing this use of wireless

technologies is that it represents a marriage

between RFID and wireless networking. This

combination of enabling technologies results in an

entirely new way of accomplishing an old task. In

small groups,

Brainstorm other combinations of existing technologies

to create new approaches to existing business

activities.

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Network Concepts

NetworkAn interconnected chain, group or system

Number of possible connections on a network is N * (N-1)Where N = number of nodes (points of

connections on the network)Example, if there are 10 computers on a

network, there are 10 * 9 = 90 possible connections

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Metcalfe’s Law

The usefulness of a network equals the square

of the number of users

On a small network, a change in technology

affects technology only

On a large network like the Internet, a change

in technology affects social, political and

economic systems

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Telecommunications

Telecommunications

Exchange of information in any form (voice,

data, text, images, audio, video) over networks

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Trends in Telecommunications

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Open Systems

Information systems that use common standards for hardware, software, applications and networks

Internet networking technologies are a common standard for open systems

Connectivity: Ability of networked computers to easily access and

communicate with each other and share information Interoperability:

The ability of an open system to enable end user applications to be accomplished using different varieties of computer systems, software packages, and databases provided by a variety of interconnected networks

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Middleware

Any programming that serves to “glue

together” two separate programs

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Digital Network Technologies

Rapid change from analog to digital network technologies

Analog: voice-oriented transmission, sound waves

Digital: discrete pulse transmissionDigital allows:

Higher transmission speedLarger amounts of informationGreater economyLower error ratesMultiple forms of communications on same circuit

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Internet2

Next generation of the Internet

High-performance network

In use at 200 universities, scientific

institutions, communications corporations

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Business Value of Telecommunication Networks

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The Internet

Over 46 million servers (2004)

710 – 945 million users (2004)

No central computer system

No governing body

No one owns it

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Internet Service Provider

ISP

A company that specializes in providing easy

access to the Internet

For a monthly fee, you get software, user name,

password and access

ISPs are connect to one another through

network access points

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Popular uses of the Internet

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Using the Internet for business

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Business value of the Internet

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An Intranet

A network inside an organizationThat uses Internet technologies (such as Web

browsers and servers, TCP/IP protocols, HTML, etc.)

To provide an Internet-like environment within the organization

For information sharing, communications, collaboration and support of business processes

Protected by security measures Can be accessed by authorized users through the

Internet

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Enterprise Information Portal

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Extranet

Network links that use Internet technologies

To connect the Intranet of a business

With the Intranets of its customers, suppliers or

other business partners

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Extranet Uses

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Case 2: Maryland and ColoradoServing their customers without using

wires

Earth Alert Emergency Management System in

Maryland provides

Devices to communicate warning to individuals

before a disaster, and

Tools to collect timely information after a disaster

Aurora Colorado

Connects police and fire department vehicles via

wire-less connections

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Case Study Questions

1. What is the business value of advanced mobile

technologies to Maryland’s emergency

management services?

2. In what other government services could GPS

serve to provide business value? Give some

examples.

3. Are there disadvantages or risks associated with

the deployment of GPS systems to monitor the

location of people? Explain.

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Real World Internet Activity

1. The global positioning system (GPS) is a major technological achievement that has broad-reaching implications for business. Using the Internet,

See if you can find other innovative uses for GPS. Good places to start familiarizing yourself with

current accomplishments are The GPSWorld site at

http://www.gpsworld.com/gpsworld/ The GPS Overview at

http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html

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Real World Group Activity

The first Real World Case in this chapter discussed

the combination of two existing technologies, RFID

and wireless networking, to create an innovative

business solution. In small groups,

Brainstorm innovative applications of GPS and other

existing technologies.

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Telecommunications network

Any arrangement where a sender transmits a

message to a receiver over a channel

consisting of some type of medium

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Telecommunications network components

Terminals: any input/output device that uses networks to transmit or receive data

Telecommunications Processors: devices that support data transmission and reception

Telecommunications Channels: media over which data are transmitted and received

Computers: all sizes and typesTelecommunications Control Software: programs

that control telecommunications activities

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Telecommunications network model

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Wide Area Network (WAN)

Telecommunications network that covers a large geographic area

Source: Courtesy of Cisco Systems Inc.

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Local Area Network (LAN)

Connect computers within a limited physical area such as an office, classroom, or building

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Virtual Private Networks (VPN)

A secure network that uses the Internet

as its backbone but relies on firewalls,

encryption and other security

A pipe traveling through the Internet

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VPN

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Client/Server networks

Clients: End user personal computers or

networked computers

Interconnected by LANs

Servers: manage networks

Processing shared between clients and

servers

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Client/Server Network

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Network Computing

Networks are the central computing resource of the organization

Thin clients: network computers and other clients provide a browser-based user interface

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Peer-to-peer networks

Networks that connect from one PC to another

PC

Common use is the downloading and trading

of files

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Peer-to-Peer Network

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Telecommunications Media

Twisted-pair wire:

Ordinary telephone

wire

Copper wire

twisted into pairsSource: Phil Degginger/Getty Images.

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Telecommunications Media

Coaxial cable:

Sturdy copper or

aluminum wire

wrapped with

spacers to insulate

and protect it

Source: Ryan McVay/Getty Images.

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Telecommunications Media

Fiber-optic cable:

One or more hair-

thin filaments of

glass fiber

wrapped in a

protective jacket

Source: CMCD/Getty Images.

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Problem of “The Last Mile”

Network providers use fiber optic to provide

backbone

But houses are connected to the backbone via

twisted-pair

Cannot get the benefit of the faster, better

technology

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Wireless Technologies

Terrestrial microwaveEarthbound microwave systems that transmit

high-speed radio signals in a line-of-sight path

Between relay systems spaced approximately 30-miles apart

Communications satellitesSatellite serves as relay stations for

communications signals

Uses microwave radio signals

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Wireless Technologies

Cellular and PCS telephone and pager systemsDivide the geographic area into small areas or

cellsEach cell has transmitter or radio relay antenna

to send message from one cell to anotherWireless LANs

Radio signals within an office or buildingConnect PCs to networks

BluetoothShort-range wireless technologyTo connect PC to peripherals such as printer

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Wireless Web

Connect portable communications devices to the Internet

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Telecommunications Processors

Modems

Convert digital signals from a computer into

Analog frequencies that can be transmitted over

ordinary telephone lines

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Comparing modem and other technologies

6-53

Internetwork Processors

Switch – makes connections between

telecommunications circuits in a network

Router – intelligent communications processor

that interconnects networks based on different

protocols

Hub – a port switching communications processor

Gateway – connects networks using different

communications architectures

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Communications Processors

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Telecommunications Processors

Multiplexer

Allows a single communications channel to carry

simultaneous data transmissions from many

terminals

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Telecommunications Software

Used by servers and other computers to

manage network performance

Network Operating Systems

Middleware

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Network management functions

Traffic Management – manage network resources and traffic to avoid congestion and optimize service levels to users

Security – provide authentication, encryption, firewall, auditing and enforcement

Network Monitoring – troubleshoot and watch over the network, informing network administrators of potential problems before they occur

Capacity Planning – survey network resources and traffic patterns and users’ needs to determine how best to accommodate the needs of the network as it grows and changes

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Network Topologies

Topology: structure of a network

Star: ties end user computers to a central

computer

Ring: ties local computer processors together in a

ring on a relatively equal basis

Bus: local processors share the same

communications channel

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Network Topologies

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Network Architectures & Protocols

Protocol: standard set of rules and procedures

for the control of communications in a network

Network Architecture:

Master plan of standard protocols, hardware,

software and interfaces between end users and

computer systems

Goal of promoting an open, simple, flexible, and

efficient telecommunications environment

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OSI & TCP/IP Models

Open Systems Interconnection (OSI) ModelA seven-layer model that serves as a standard

model for network architecturesModel for how messages should be transmitted

between two points in a networkEach layer adds functions

Transmission Control Protocol / Internet Protocol (TCP/IP)A five layer telecommunications protocol used

by the Internet

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OSI & TCP/IP Models

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Internet Telephony

Using an Internet connection to pass voice

data using IP

Voice over IP (VoIP)

Skips standard long-distance phone charges

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Bandwidth

Bandwidth

Frequency range of a telecommunications channel

Determines transmission rate

Classified in bits per second (bps)

Transmission Rates:

Narrow-band – low-speed

Broadband – high-speed

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Transmission Speeds

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Switching Alternatives

Circuit Switching

Switch opens a circuit to establish a link

between a sender and receiver

it remains open until the communication session

is completed

Packet Switching

Break messages into groups called packets

Transmit packets separately

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Network Interoperability

Ensure that anyone anywhere on one network

Can communicate

With anyone anywhere on another network

Telecommunications as discussed in this chapter

wouldn’t be possible without interoperability

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Case 3: Voice Over IP is the Real Thing

VoIP works by

Digitizing a voice signal,

Chopping it into packets, and

Sending them over a company’s network or the

Internet

Packets are reassembled at the destination

Minnesota Department of Labor has cut its

monthly phone bill in half

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Case Study Questions

1. What are the main benefits that can be gained by companies that switch to VoIP systems?

2. What are some of the major cost factors that may limit a positive rate of return from investments in VoIP projects?

3. Should more companies switch to VoIP systems? Visit the websites of Avaya and Cisco Systems to view their VoIP news, products, and services to help you answer.

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Real World Internet Activity

1. VoIP is becoming a highly competitive marketplace for the delivery of services and the development of software to support the process. Using the Internet,

See if you can identify who the major players are in this market.

Where do you see the next significant development for VoIP?

Do you think the concept will eventually replace conventional telephone technologies? Why or why not?

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Real World Group Activity

The original concept for the Internet never included many of the uses we have found for it and consider commonplace today. While Internet2 is on the horizon, we need to think about what uses we may want from the Internet in the future. In small groups,Brainstorm how we might use the Internet in the

future.

Do we run the risk of overloading the Internet or relying on it too much?