“TELECOMMUNICATIONS AND THE INTERNET”

BY

SUMANA SHARMA

The whole world is within your reach!

TELECOMMUNICATION IN ORGANIZATIONS!

SIMPLIFYING THE JARGON!

Telecommunications refers to the transmission of information (voice,data,pictures,video,sound) from one point to another over a network.

Bandwidth is the data carrying capacity of the network. Greater the bandwidth,faster is the speed of data transmission!

INTERPERSONAL COMMUNICATION APPLICATIONS

e Mail or Electronic mail Internet relay chat or instant

messaging Newsgroups Mailing lists Fax Voice mail Video conferencing

BUSINESS COMMUNICATION

APPLICATIONS e Commerce or Electronic commerce Electronic data interchange(EDI) Telecommuting Electronic funds transfer Distance learning Telemedicine

COMPONENTS OF A COMPUTER NETWORK

Sender or a Transmitter Receiver Transmission media Protocols or rules

TYPES OF COMMUNICATION

REAL TIME

Instant messaging, video conferencing NON REAL TIME

E mail, voice mail.

HOW DO COMPUTERSCOMMUNICATE WITH EACH

OTHER?

Computers talk in Binary Language. They use different combinations of the digits 0 and 1 to express all that they want to say! If we wish to communicate with a computer we would need to translate! The process of translation is called “digitization”

COMPUTING – HOW COMPUTERS PERFORM TASKS?

Centralized computing Distributed computing Collaborative computing

TYPES OF COMPUTER NETWORKS

PRIVATE BRANCH EXCHANGE OR PBX

While at work, majority of the telephone calls made by employees are for intra-company communication!

It is feasible for medium to large businesses to have their own telephone exchange.

LOCAL AREA NETWORK

A group of computers and other devices in a relatively limited area (such as a single building) that are connected by a communications link

enables every device to interact with any other device on the network

CAMPUS AREA NETWORK

An interconnection of local-area networks within a limited geographical space, such as a school campus or a military base.

WIDE AREA NETWORK (WAN)

A system of interconnected computers encompassing a large geographic range, including cities, states, or countries

METROPOLITAN AREA NETWORK

A data communications network that covers an area larger than a campus

area network and smaller than a wide area network,

interconnects two or more LANs, and usually covers an entire metropolitan

area, such as a large city and its suburbs.

PERSONAL AREA NETWORK

Network in which all devices are distributed locally around an individual person (range is from 10-100m).

These different devices are capable of communicating with each other!

GLOBAL AREA NETWORK

An international network that spans all departments, offices, and subsidiaries of the corporation.

ENTERPRISE NETWORK

A term coined by IBM to describe a private network, linking sites within a company.

VALUE ADDED NETWORK

This is is a privately owned, or proprietary network.

A company that acts as a clearinghouse for electronic transactions between trading partners

INTERNET

INTERNET IS NOTHING BUT A NETWORK OF NETWORKS!!

Born when DoD started a project called Advanced Research Projects Agency Network (ARPANET)

Goal was to develop a decentralized system that could withstand an enemy attack.

UCLA, SRI, UCSB, and Utah were the first four nodes.

INTERNET RELIES ON PACKET SWITCHING TECHNOLOGIES

A huge amount of data can be split into smaller chunks and then sent across the transmission medium.

At the receiving end all the chunks are put together to retrieve the original data.

Very efficient technology that makes best use of available bandwidth!

HOW DO NETWORKS TALK TO EACH OTHER?

Using TCP/IP (Transmission control protocol/Internet protocol).

TCP deals with breaking a large piece of data into manageable chunks. These tiny packets of data are called datagrams.

IP deals with attaching an address label over them so that that they can reach the desired destination.

ROUTERS- A MEANS OF CONNECTING TWO NETWORKS

High speed device capable of relaying data from one network to another.

DIFFERENCE BETWEEN INTERNET AND THE WORLD

WIDE WEB OR WWW

Internet is a network of networks while the world wide web is a collection of documents(web pages) that are held on and sent through the internet

IP ADDRESSES AND DOMAIN NAMES

The internet is a massive computer network comprising of millions of computers.

Each computer has a unique address associated with it.

This is called an IP address. For example: 212.14.56.39 is an IP address.

This Numeric address can be mapped to a name (web address) for ease of remembering.

DOMAIN NAME OR URL (UNIFORM RESOURCE LOCATOR)

Domain name is an alias for the “difficult to remember” IP address.

Example : www.vcu.edu

Web

Domain name

Educational institutions

ROLE OF ICANN IN MANAGING IP TO DOMAIN NAME MAPPING

ICANN (Internet corporation for assigned names and numbers) manages the exhaustive database consisting of domain names and their corresponding IP addresses and vice versa.

WORLD WIDE WEB

A web browser provides an easy-to-use interface for accessing the information on the World Wide Web.

Hypertext documents contains information and hyperlinks.

Hyperlinks are links to other related documents.

http://www.vcu.edu/ Web pages are written in HTML (Hyper

text mark up language)

INTERNET IS NOBODY’S PRIVATE

PROPERTY! Nobody owns the internet! Many non-profit organizations help in

maintaining it though! Examples: ISOC (Internet society) ICANN (Internet society for assigned

names and numbers) IAB (Internet architecture board)

DIFFERENT WAYS OF ACCESSING THE INTERNET

Individuals usually connect to the Internet using either:

Dial Up DSL or Digital subscriber line ISDN or Integrated services digital

network Cable modems Satellite connections

DIAL UP

Uses normal telephone line to establish a connection.

Maximum speed of 56 Kbps can be achieved.

DIGITAL SUBSCRIBER LINE

Uses normal telephone line to achieve extremely high data rates.

Two popular variations are : ADSL or Asymmetric DSL Downstream speed of 1.5 Mbps to 9

Mbps Upstream speed of 16 to 640 Kbps SDSL or Symmetric DSL Downstream and upstream speeds of 3

Mbps

CABLE MODEMS

Utilizes coaxial cable to access the internet.

Requires a cable modem to be installed.

Data rates of upto 2 Mbps can be achieved.

SATELLITE CONNECTIONS

Utilizes geostationary satellites to access the internet.

Propagation delay is a major concern

HOW BUSINESSES OR OTHER ORGANIZATIONS ACCESS THE

INTERNET

Using Leased lines. Using ATM or Asynchronous transfer

mode networks

LEASED LINE

A leased line is a dedicated phone line to your telephone exchange.

It has two popular variants: T1 = 24 telephone lines

Data rates of upto 1.5 Mbps T3= 672 telephone lines Data rates of upto 45 Mbps

ATM

Based on packet switching. Fixed packet size of 53 bytes. Data rates of upto 2.2 Gbps can be

achieved.

SECURITY – THE MILLION DOLLAR QUESTION!

AuthenticationLog in with your password FirewallsShield information from hackers or

unauthorized users! EncryptionThe sender turns on the lock.Only the

receiver has the key

POPULAR INTERNET TOOLS

e mail: Used for transmitting and receiving messages.

Telnet: An Internet protocol that allows a user at a remote terminal to login to other computer systems on the Internet

FTP or File transfer protocol:A way of transferring files over the Internet from one computer to another.

Internet tools - continued Usenet: Collection of newsgroups

across the internet. Mailing lists: Allows group of people

with a common interest to send messages to each other.

Archie: Juggle through FTP sites to see if they have the information you are looking for!

Internet tools - continued Gopher: Was the means of accessing

information(plain text) on the internet, before the world wide web was born!

VoIP or Voice over IP: A technology for transmitting ordinary telephone calls over the Internet using packet-linked routes

WAIS or Wide area Information server: distributed information retrieval system on the Internet used to retrieve documents using keywords searching defined databases.