“TELECOMMUNICATIONS AND THE INTERNET” BY SUMANA SHARMA

TELECOMMUNICATION IN ORGANIZATIONS! The whole world is within your reach!

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 COMPUTERS COMMUNICATE 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 Educational institutions Domain name

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! Authentication Log in with your password Firewalls Shield information from hackers or unauthorized users! Encryption The 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.