Chapter6 TELECOMMUNICATIONS AND NETWORKS. Content The Networked Enterprise – The Concept of a Network – Trends in Telecommunications – The Business Value.

Chapter6

TELECOMMUNICATIONS AND NETWORKS

Content• The Networked Enterprise

– The Concept of a Network– Trends in Telecommunications– The Business Value of Telecommunications Networks– The Internet Revolution– The Role of Intranets– The Role of Extranets

• Telecommunications Network Alternatives– A Telecommunications Network Component– Types of Telecommunications Networks– Telecommunications Media– Telecommunications Processors– Network Topologies– Network Architectures and Protocols

The Concept of a Network

• What is network? Network means an interconnected or interrelated chain, group, or system.

• The concept of networks can be expressed as a mathematical formula that calculates the number of possible connections or interactions in a one-way communication environment:N (N -1), or N2 - N . N refers to the number of nodes

(points of connection) on the network.

Trends in Telecommunications

The Business Value of Telecommunications Networks

The Internet Revolution• The revolution of internet:

– December 1991: It had about 10 servers.– January 2004: The Internet was estimated to have more than 46 million

connected servers with a sustained growth rate in excess of 1 million servers per month.

– January 2007: The Internet was estimated to have more than 1 billion users with Web sites in 34 languages.

– The Internet is constantly expanding as more and more businesses and other organizations and their users, computers, and networks join its global Web.

– To connected to internet for access we need ISP.– After you connected to internet we need to used Internet application to

request the internet service.– Business use of the Internet has expanded from an electronic information

exchange to a broad platform for strategic business applications.– The Business Value of the Internet is cost saving.

Popular uses of the Internet

how a company can use the Internet for business

How companies are deriving business value from their e-business and e-commerce applications

The Role of Intranets• What is Intranet? An intranet is a network inside an

organization that uses Internet technologies for information sharing, communications, collaboration, and the support of business processes.

• The business value of intranet is:– Communications and Collaboration: Intranets can

significantly improve communications and collaboration within an enterprise.

– Web Publishing: The advantage of developing and publishing hyperlinked multimedia documents to hypermedia databases accessible on World Wide Web servers has moved to corporate intranets.

– Business Operations and Management: Intranets are also being used as the platform for developing and deploying critical business applications to support business operations and managerial decision making across the inter-networked enterprise.

– Intranet Portal Management: Organizations must employ IT and IS professionals to manage the functions of the intranet along with maintaining the various hardware and software components necessary for successful operations.

The Role of Extranets

• What is extranet? extranets are network links that use Internet technologies to interconnect the intranet of a business with the intranets of its customers, suppliers, or other business partners.

A Telecommunications Network Component

• Terminals: input/output device that uses telecommunications networks to transmit or receive data(Ex: Personal computers, network computers, net boxes, or information appliances)

• Telecommunications processors: which support data transmission and reception between terminals and computers(modems, switches, and routers).

• Telecommunications channels: over which data are transmitted and received(Wire and wireless).

• Computers: all sizes and types are interconnected by telecommunications networks so that they can carry out their information processing assignments. (mainframe or microcomputer).

• Telecommunications control software: consists of programs that control telecommunications activities and manage the functions of telecommunications networks(telecommunications monitors, network operating, Web browsers).

The five basic components in a telecommunications network

Types of Telecommunications Networks

• Wide Area Networks: Telecommunications networks covering a large geographic area.

• Metropolitan Area Network: Networks that cover a large city.• Local Area Networks: connect computers and other information processing devices

within a limited physical area, such as an office, classroom, building, manufacturing plant, or other worksite.

• Virtual Private Networks: A virtual private network is a secure network that uses the Internet as its main backbone network but relies on network firewalls, encryption, and other security features of its Internet and intranet connections and those of participating organizations.

• Client/Server Networks: They are interconnected by local area networks and share application processing with network servers, which also manage the networks.

• Network Computing: It views networks as the central computing resource of any computing environment.

• Peer-to-Peer Networks: The use for peer-to-peer networks is the downloading and trading of files and PeerCast.

Type of Telecommunication Network

LAN

WAN

VPNNetwork Computing Cient/Server

Peer-to-Peer Networks

Telecommunications Media• Wired Technologies:

– Twisted-Pair Wire– Coaxial Cable– Fiber Optics

• Wireless Technologies:– Terrestrial Microwave: involves earthbound microwave systems that transmit

high speed radio signals in a line-of-sight path between relay stations spaced approximately 30 miles apart.

– Communications Satellites: high-earth orbit (HEO) communications satellites are placed in stationary geosynchronous orbits approximately 22,000 miles above the equator.

– Cellular and PCS Systems– Wireless LANs– Bluetooth– The Wireless Web

Wired Technology

Wireless Application Protocol(WAP)

Telecommunications Processors

• Modems: They convert the digital signals from a computer or transmission terminal at one end of a communications link into analog frequencies that can be transmitted over ordinary telephone lines.

• Inter-Network Processors: Telecommunications networks are interconnected by special-purpose communications processors such as switches, routers, hubs, and gateways.

• Multiplexers: is a communications processor that allows a single communications channel to carry simultaneous data transmissions from many terminals(FDM and TDM).

Comparing modem and telecommunications technologies for Internet and other network access

Examples of some of the communications processors

Network Topologies

• Bus: It is a network in which local processors share the same bus, or communications channel.

• Ring network ties local computer processors together in a ring on a more equal basis.

• Star network ties end-user computers to a central computer.

The ring, star, and bus network topologies

Network Architectures and Protocols

• Protocols: a standard set of rules and procedures for the control of communications in a network.

• Network Architectures:– The OSI Model

• Layer 1: The physical layer • Layer 2: The data link layer• Layer 3: The network layer• Layer 4: The transport layer• Layer 5: The session layer• Layer 6: The presentation layer• Layer 7: The application layer

– The Internet’s TCP/IP

OSI and TCP/IP Model