bvoc 106 internet tutorial

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LEARNING MATERIAL by ([email protected] ) SANDEEP KUMAR SHARMA

BVOC (106) OFFICE AUTOMATION AND INTERNET

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DATA COMMUNICATIONS The term telecommunication means communication at a distance. The word data refers to information presented in whatever form is agreed upon by the parties creating and using the data. Data communications are the exchange of data between two devices via some form of transmission medium such as a wire cable. COMPONENT OF COMMUNICATION

ANALOG AND DIGITAL Data can be analog or digital. The term analog data refers to information that is continuous; digital data refers to information that has discrete states. Analog data take on continuous values. Digital data take on discrete values.

DATA TRANSMISSION MODES The transmission of binary data across a link can be accomplished in either parallel or serial mode. In parallel mode, multiple bits are sent with each clock tick. In serial mode, 1 bit is sent with each clock tick. While there is only one way to send parallel data, there are two subclasses of serial transmission: asynchronous, synchronous

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Parallel transmission

Serial transmission

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Asynchronous transmission

Synchronous transmission

Digital and Analog Transmission

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Bit rate is the number of bits per second. Baud rate is the number of signal elements per second. In the analog transmission of digital data, the baud rate is less than or equal to the bit rate.

Data Transmission Media

Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable.

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Coaxial cable

Fiber Optic Cable Unguided media transport electromagnetic waves without using a physical conductor. This type of communication is often referred to as wireless communication.

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� Radio waves are used for multicast communications, such as radio and television, and

paging systems � Microwaves are used for unicast communication such as cellular telephones, satellite

networks, and wireless LANs. � Infrared signals can be used for short-range communication in a closed area using

line-of-sight propagation.

Propagation methods

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Data Transmission Speed

Data transfer rate is the average number of bits (bitrate), characters or symbols (baud rate), or blocks per unit time passing between equipment in a data transmission system. Most commonly, measurements of data transfer rate are reported in multiples of unit bits per second (bit/s) or occasionally in bytes per second (B/s). The data rates of modern residential high-speed Internet connections are most commonly expressed in multiples of bits per second, such as megabits per second (Mbit/s).

Data transfer speed on the other hand is expressed in bits. In bit rates the abbreviations are as follows:

• 1 kbps = 1,000 bits per second • 1 Mbps = 1,000,000 bits per second. • 1 Gbps = 1,000,000,000 bits per second.

kbps (kilobits/sec) means thousands of bits per second mbps or Mbps (megabits/sec) means millions of bits per second gbps or Gbps (gigabits/sec) means billions of bits per second (where "billion"= 1,000,000,000.00") tbps (terabits/sec) means trillions of bits per second (as in "terabit router" or "terabit speeds") pbps (petabits/sec) means quadrillions of bits per second.

Examples:

• "Gigabit Ethernet [1000Base-T] is capabile of speeds up to 1000 mbps (mega-bits per second), or 1 gbps."

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LAN connecting 12 computers.

LEARNING MATERIAL by (

Network made of four WANs and

CLIENT AND SERVER Client-Server: One the remote process acts as Client and requests some resource from another application process acting as Server. distributed application structure that partitions resource or service, called servers, and service requesters, calledmodel, any process can act as Server or Client. This not the machine or size of the machine or its computing power which makes it server but it is the feature of serving request that makes it server. Examples of computer applications that use the clientare Email, network printing, and the

INTRANET

An intranet is a private network, accessible only to an organization's staff.

range of information and services from the organization's internal IT systems are available

that would not be available to the public from the• Intranet is system in which multiple PCs are connected to each other.


Network made of four WANs and two LANs

One the remote process acts as Client and requests some resource from another application process acting as Server. The client–server model distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients.model, any process can act as Server or Client. This not the machine or size of the machine or

hich makes it server but it is the feature of serving request that makes Examples of computer applications that use the client

, and the World Wide Web.

network, accessible only to an organization's staff.


that would not be available to the public from the Internet. Intranet is system in which multiple PCs are connected to each other.

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) SANDEEP KUMAR SHARMA

One the remote process acts as Client and requests some resource from of computing is a

tasks or workloads between the providers of a clients. In client-server

model, any process can act as Server or Client. This not the machine or size of the machine or hich makes it server but it is the feature of serving request that makes

Examples of computer applications that use the client–server model

network, accessible only to an organization's staff. Generally a wide


Intranet is system in which multiple PCs are connected to each other.

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• PCs in intranet are not available to the world outside the intranet.

• Usually each company or organization has their own Intranet network and members/employees of that company can access the computers in their intranet.

• Each computer in Intranet is also identified by an IP Address which is unique among the computers in that Intranet.

Similarities in Internet and Intranet

• Intranet uses the internet protocols such as TCP/IP and FTP.

• Intranet sites are accessible via web browser in similar way as websites in internet. But only members of Intranet network can access intranet hosted sites.

• In Intranet, own instant messengers can be used as similar to yahoo messenger/ Gtalk over the internet.

Differences in Internet and Intranet

• Internet is general to PCs all over the world whereas Intranet is specific to few PCs.

• Internet has wider access and provides a better access to websites to large population whereas Intranet is restricted.

• Internet is not as safe as Intranet as Intranet can be safely privatized as per the need.

INTERNET & HOW THE INTERNET WORKS The Internet has had a profound effect on the world of computers. The Internet, as it is known today, was born in 1983 when ARPANET was split into two interconnected networks: ARPANET and MILNET. The size of the Internet doubled when NSFnet joined the Internet in 1986.The Internet has proven to be a reliable means of transmitting data. The Internet is a worldwide collection of networks that links millions of businesses, government offices, educational institutions, and individuals. Data is transferred over the Internet using servers, which are computers that manage network resources and provide centralized storage areas, and clients, which are computers that can access the contents of the storage areas. The data travels over communications lines. Each computer or device on a communications line has a numeric address called an IP (Internet protocol) address, the text version of which is called a domain name. Every time you specify a domain name, a DNS (domain name system) server translates the domain name into its associated IP address, so data can route to the correct computer.

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• hosted.

• Internet is accessible to every user all over the world.

WAYS TO ACCESS THE INTERNET

You can access the Internet through an Internet service provider, an online service provider, or a wireless service provider. An Internet service provider (ISP) provides temporary Internet connections to individuals and companies. An online service provider (OSP) also supplies Internet access, in addition to a variety of special content and services. A wireless service provider (WSP) provides wireless Internet access to users with wireless modems or Web-enabled handheld computers or devices.

Employees and students often connect to the Internet through a business or school network that connects to a service provider. For home or small business users, dial-up access provides an easy and inexpensive way to connect to the Internet. With dial-up access, you use a computer, a modem, and a regular telephone line to dial into an ISP or OSP. Some home and small business users opt for newer, high-speed technologies. DSL (digital subscriber line) provides high-speed connections over a regular copper telephone line. A cable modem provides high-speed Internet connections through a cable television network.

World Wide Web

The World Wide Web is a popular segment of the Internet that contains billions of documents called Web pages. These documents can contain text, graphics, sound, video, and built-in connections, or links, to other Web pages stored on computers throughout the world.

• Tim Berners-Lee, CERN (Switzerland) • First web server and client, 1990 • Established a common language for sharing information on computers • Lots of previous attempts (Gopher, WAIS, Archie, Xanadu, etc.)

The World Wide Web is a system of Internet servers that supportspecially formatted documents. The documents are formatted in a markup language called HTML (HyperText Markup Language) that supports links to other documents, as well as graphics, audio, and video files. This means you can jump from one document to another simply by clicking on hot spots

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Domain name system (DNS) An Internet address has four fields with numbers that are separated by periods or dots. This type of address is known as an IP address. Rather than have the user remember long strings of numbers, the Domain Name System (DNS) was developed to translate the numerical addresses into words. For example, the address fcit.usf.edu is really 131.247.120.10.

Each part of a domain name contains certain information. The first field is the host name, identifying a single computer or organization. The last field is the top-level domain, describing the type of organization and occasionally country of origin associated with the address.

Top-level domain names include:

.com Commercial

.edu Educational

.gov US Government

.int Organization

.mil US Military

.net Networking Providers

.org Non-profit Organization

The IP Address

The Internet Protocol moves data between hosts in the form of datagram. Each datagram is delivered to the address contained in the Destination Address of the datagram's header. The Destination Address is a standard 32-bit IP address that contains sufficient information to uniquely identify a network and a specific host on that network.

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An IP address contains a network part and a host part, but the format of these parts is not the same in every IP address. The number of address bits used to identify the network, and the number used to identify the host, varies according to the prefix length of the address. We begin with a discussion of traditional IP address classes.

• Less than 128, the address is class A; the first byte is the network number, and the next three bytes are the host address.

• From 128 to 191, the address is class B; the first two bytes identify the network, and the last two bytes identify the host.

• From 192 to 223, the address is class C; the first three bytes are the network address, and the last byte is the host number.

• From 224 to 239, D the address is multicast. There is no network part. The entire address identifies a specific multicast group.

• Class E Greater than 239, the address is reserved. We can ignore reserved addresses.

WEB BROWSERS A web browser, or 'browser' for short, is computer software application that allows a person to view the internet. The browser operates at the application layer of the Open Systems Interconnection (OSI) model.

Popular Web Browsers and How They Work:

The most popular web browsers that are used today are Mozilla Firefox, Google Chrome, Microsoft Internet Explorer, Apple Safari and the Opera browser. These browsers are free and available for download and use. Web browsers allow users to view resources that are stored on a server. For example, if you were to visit www.google.com, you are actually viewing a file that is displayed using the web browser. This file is drafted using the hyper text markup language or HTML for short. These files, or web pages as they're commonly known, are pulled from the web server and then translated by the web browser for the user to view. If you do not have a web browser and attempt to view the HTML file, you will see numerous amounts of code lines that may not make sense to the average user. The browser will translate those code lines that makes it easily readable for the user.

Browsers are not just good at viewing web pages, they can also be used to download and upload files as well. Browsers can facilitate the file transfer protocol, or FTP for short. FTPs allow users to upload or download files to web servers using a browser

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UNIT -2

ISO-OSI SEVEN LAYRED MODEL

TCP/IP (INTERNET MODEL)

Uniform Resource Locators (URL) A URL contains information on how and where to access a document. How to access a document is often reflected by the name of the scheme that is part of the URL, such as http, ftp, or telnet. Where a document is located is often embedded in a URL by means of the DNS name of the server to which an access request can be sent, although an IP address can also be used. The number of the port on which the server will be listening for such requests is also part of the URL; when left out, a default port is used. Finally, a URL also contains the name of the document to be looked up by that server, leading to the general structures shown in Fig.

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A variety of services are used widely on the Internet, including e-mail, FTP, newsgroups and message boards, mailing lists, chat rooms, and instant messaging. E-mail (electronic mail) is the transmission of messages and files via a computer network. You use an e-mail program to create, send, receive, forward, store, print, and delete messages. To receive messages, you need an e-mail address, which is a combination of a username and a domain name that identifies a user.

FTP (File Transfer Protocol)

FTP (File Transfer Protocol) is an Internet standard that allows you to upload and download files with other computers on the Internet. FTP is a client-server protocol that relies on two communications channels between client and server: a command channel for controlling the conversation and a data channel for transmitting file content. Clients initiate conversations with servers by requesting to download a file. Using FTP, a client can upload, download, delete, and rename, move and copy files on a server. A user typically needs to log on to the FTP server,

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An FTP server is a computer that allows you to use FTP to upload files to, and download files from, an FTP site. With anonymous FTP, anyone can transfer some, if not all, available files. A newsgroup is an online area in which users conduct written discussions about a particular subject. The computer that stores and distributes newsgroup messages is called a news server. You use a program called a newsreader to access a newsgroup, read previously entered messages (called articles), and add (post) messages of your own

FTP (File-Transfer-Protocol) is a way for you to copy files from one computer to another over a network such as the internet. This is usually done for copying files from your PC to a server for publishing websites. Some people use this as a method for distributing software from a server.

The way to connect your PC to an FTP server is to go to a command prompt and take a known FTP address and type:

ftp someservername

example:ftp wuarchive.wustl.edu

After typing that in at a command prompt, you will be asked for a username and password. For the example above, you can use the username: anonymous and just hit the enter-key for the password.

TELNET

(TELecommunication NETwork) is a network protocol used on the Internet or local area network (LAN) connections. It was developed in 1969 beginning with RFC 15 and standardized as IETF STD 8, one of the first Internet standards.

Telnet provides access to a command-line interface on a remote host via a virtual terminal connection which consists of an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP).

The network terminal protocol (TELNET) allows a user to log in on any other computer on the network. We can start a remote session by specifying a computer to connect to. From that time until we finish the session, anything we type is sent to the other computer.

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The Telnet program runs on the computer and connects your PC to a server on the network. We can then enter commands through the Telnet program and they will be executed as if we were entering them directly on the server console. This enables us to control the server and communicate with other servers on the network. To start a Telnet session, we must log in to a server by entering a valid username and password. Telnet is a common way to remotely control Web servers.

Chat

A chat is real-time (meaning everyone involved in the chat is online at the same time) typed conversation that takes place on a computer. A location on an Internet server that permits users to chat is called a chat room. Some chat rooms support voice chats and video chats, where you can hear or see others and they can hear or see you as you chat. A chat client is a program on your computer that allows you to connect to a chat server and start a chat session.

Instant messaging (IM) is a real-time Internet communications service that notifies you when one or more people are online and then allows you to exchange messages or join a private chat room.

Chat vs. IM

The terms chat and IM are sometimes used interchangeably. However, they can have slightly different meanings:

• Chat often occurs in a virtual chat room, which can include many different

people who may or may not know each other. Many chat rooms focus on a particular topicor interest.

• IM usually includes a list of your contacts, called a Buddy List or Friend List, which allows you to see who is online. IM is especially suited for one-on-one communication, but it's possible to send messages to multiple people at once. IM is technically a kind of chat, and some IM services use the term "chat" instead.

• Here are numerous chat and IM programs you can download, including Skype, ICQ, AOL Instant Messenger(AIM), and Yahoo! Messenger (all of these can also perform voice and video chat). In addition, there are manybrowser-based services that don't require downloading. For

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example, Facebook and Gmail allow you to chat with your contacts whenever you're signed in.

• If you have a smartphone or mobile device, it's possible to use chat or IM when you're away from your computer. Popular mobile chat services include IMO and eBuddy.

E-mail Electronic mail, most commonly referred to as email, E-mail since around 1993, is a method of exchanging digital messages from an author to one or more recipients. Email operates across the Internet or other computer networks. Today’s email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need connect only briefly, typically to a mail server, for as long as it takes to send or receive messages. An Internet email message consists of three components, the message envelope, the message header, and the message body. The message header contains control information, including, minimally, an originator's email address and one or more recipient addresses. Usually descriptive information is also added, such as a subject header field and a message submission date/time stamp. 1- Transfer of textual messages, through which documents from any program can be sent, except the executive programs (extension: .exe)

2-structure of the e-mail address: user name, @ symbol and a domain name (name of the computer on the Internet where mail will be delivered to the recipient), for example- [email protected], [email protected]

3-e-mail advantages: fast (instant) delivery, low cost, flexibility of using mail account on websites.

VoIP (Voice over Internet Protocol).

Voice over Internet Protocol (VoIP) is a technology that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line. Some VoIP services may only allow you to call other people using the same service, but others may allow you to call anyone who has a telephone number - including local, long distance, mobile, and international numbers. VoIP services convert your voice into a digital signal that travels over the Internet. If you are calling a regular phone number, the signal is converted to a regular telephone signal before it reaches the destination. VoIP can allow you to make a call directly from a

computer, a special VoIP phone, or a traditional phone connected to a special adapter. Voice over Internet Protocol is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls by sending voice data in

LEARNING MATERIAL by (

packets using IP . VoIP includes:call.

VoIP can turn a standard Internet connection into a way to placepractical upshot of this is that by using some of the free VoIP make Internet phone calls, you're bypassing the phone comexample are TINGO,VIBER,SKYPE etc.

The interesting thing about VoIP is that there is not just one way to place a call. There are three different "flavors" of VoIP service in common use today:

• ATA -- The simplest and most common way is through the use of a device called an ATA (analog telephone adaptor).

• IP Phones -- These specialized phones look just like normal phones with a handset, and buttons. Wi-Fi phones allow subscribing callers to make VoIP calls from anyspot.

• Computer-to-computer -- This is certainly the easiest way to use VoIP

ISP (Internet Service Provider

An ISP, or Internet Service Providerand businesses for a monthly or yearly fee. In addition to internet connection, ISPs may also provide related services like web site hosting and development, email hosting, domain name registration etc. Different ISPs, and sometimes even the same one, offer different types of internet connections - dialup, cable and DSL broadband. Hardware such as dialup modem or a wireless modem and router are usually provided by the company. When you register with an ISP for its services, an account is created and you are provided with the login details username and password. You connect to the internet via your account and this way the company keeps a watch on your online activities.

Short for Internet Service Provider, including personal and business access to the Internet. For a monthly fee, the service provider usually provides a software package, username, password and access phone number. Equipped with a modem, you can then log on to the Internet and browse the World Wide Web and USENET, and send and receive ethe broadband modem hardware or pay a monthly fee for this equipment that is added to your ISP account billing.


. VoIP includes: Caller ID, Call waiting, Call transfer, Repeat

VoIP can turn a standard Internet connection into a way to place free phone callspractical upshot of this is that by using some of the free VoIP software that is available to make Internet phone calls, you're bypassing the phone company (and its charges) entirely. example are TINGO,VIBER,SKYPE etc.

The interesting thing about VoIP is that there is not just one way to place a call. There are ifferent "flavors" of VoIP service in common use today:

The simplest and most common way is through the use of a device called an ATA

These specialized phones look just like normal phones with a handset, allow subscribing callers to make VoIP calls from any

This is certainly the easiest way to use VoIP.

Internet Service Provider)

Internet Service Provider, is a company that offers internet access to individuals and businesses for a monthly or yearly fee. In addition to internet connection, ISPs may also provide related services like web site hosting and development, email hosting, domain name

fferent ISPs, and sometimes even the same one, offer different types of dialup, cable and DSL broadband. Hardware such as dialup modem or

a wireless modem and router are usually provided by the company. When you register with for its services, an account is created and you are provided with the login details

username and password. You connect to the internet via your account and this way the company keeps a watch on your online activities.

Short for Internet Service Provider, it refers to a company that provides Internet services, including personal and business access to the Internet. For a monthly fee, the service provider usually provides a software package, username, password and access phone number.

you can then log on to the Internet and browse the World Wide Web and USENET, and send and receive e-mail. For broadband access you typically receive the broadband modem hardware or pay a monthly fee for this equipment that is added to your

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) SANDEEP KUMAR SHARMA

transfer, Repeat dial, Return

free phone calls. The software that is available to

pany (and its charges) entirely.

The interesting thing about VoIP is that there is not just one way to place a call. There are

The simplest and most common way is through the use of a device called an ATA

These specialized phones look just like normal phones with a handset, cradle allow subscribing callers to make VoIP calls from any Wi-Fi hot

company that offers internet access to individuals and businesses for a monthly or yearly fee. In addition to internet connection, ISPs may also provide related services like web site hosting and development, email hosting, domain name

fferent ISPs, and sometimes even the same one, offer different types of dialup, cable and DSL broadband. Hardware such as dialup modem or

a wireless modem and router are usually provided by the company. When you register with for its services, an account is created and you are provided with the login details –

username and password. You connect to the internet via your account and this way the

it refers to a company that provides Internet services, including personal and business access to the Internet. For a monthly fee, the service provider usually provides a software package, username, password and access phone number.

you can then log on to the Internet and browse the World Wide mail. For broadband access you typically receive

the broadband modem hardware or pay a monthly fee for this equipment that is added to your

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FOR EXMPLE ISP : Access Smart,Tata Communications,Bharti Airtel,Bharat Sanchar Nigam,Reliance Communications,Vodafone

Live Telecast on Internet

It is the telecast of a live event, with video and audio. Some people use the term live telecast because it looks so much like television and in fact it is very similar. For a live telecast we use one, two or multiple cameras to telecast a live event. This event may be a meeting, speech, talk show, and company event, analyst event fashion show the list goes on and on. If we were broadcasting this on TV it would look exactly the same, but a live telecast is now broadcast on the web. As internet broadcasting continues to grow more and more internet broadcasters are interested in broadcasting their content live. Broadcasting live allows you to connect with your viewership in real time, along with creating a live interactive community that is based around your show. Ustream is a live streaming service that allows you to simply broadcast to the world via a webcam or streaming software like Wire cast or Vidblaster. Bambuser is an interactive live video broadcasting service, for streaming live video from mobile phones and webcams to the internet. With Google Hangouts on air you can broadcast live to your YouTube page, have up to 10 guests and use plug-in to allow you to add lower thirds and control the camera switching.

Justin.tv allows anyone to broadcast video online. Justin.tv user accounts are called "channels", and users are encouraged to broadcast a wide variety of content.