Technologies of World Wide Web:


Internet client–server applications:

Client-server architecture (client/server) is a network architecture in which each computer or process on the network is either a client or a server. Servers are powerful computers or processes dedicatedto managing disk drives (file servers), printers (print servers), or network traffic (network servers ). Clients are PCs or workstationson which users run applications. Clients rely on servers forresources, such as files, devices, and even processing power.

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TELNET

Telnet is a user command and an underlying TCP/IP protocol for accessing remote computers. Through Telnet, an administrator or another user can access someone else’s computer remotely. On the Web, HTTP and FTP protocols allow you to request specific files from remote computers, but not to actually be logged on as a user of that computer. With Telnet, you log on as a regular user with whatever privileges you may have been granted to the specific application and data on that computer.

 

A Telnet command request looks like this (the computer name is made-up):

telnet the.libraryat.whatis.edu

The result of this request would be an invitation to log on with a userid and a prompt for a password. If accepted, you would be logged on like any user who used this computer every day.

Telnet is most likely to be used by program developers and anyone who has a need to use specific applications or data located at a particular host computer.

 

File Transfer Protocol(FTP)

 

Understanding file transfer protocol

FTP stands for “file transfer protocol” and it is a means of transferring files between two computers. FTP allows you to transfer files between the directory of a server that is connected to the Web and your computer. By this means you are able to upload and download your website content to your web host for publishing to the Internet.

The File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and uses separate control and data connections between the client and the server.

 

Internet Relay Chat (IRC)

Internet Relay Chat (IRC) is a system for chatting that involves a set of rules and conventions and client/server software. On the Web, certain sites such as Talk City or IRC networks such as the Undernet provide servers and help you download an IRC client to your PC. Talk City also offers an IRC client applet that it downloads for you as part of their home page so that you can start chatting right away.

To connect and chat with other IRC users, you must either have an IRC client or a web interface that connects you to IRC servers. There are numerous software IRC clients that enable users to connect and communicate to other IRC servers. We suggest the HydraIRC program.

 

Multipurpose Internet Mail Extensions(MIME)

MIME (Multi-Purpose Internet Mail Extensions) is an extension of the original Internet e-mail protocol that lets people use the protocol to exchange different kinds of data files on the Internet: audio, video, images, application programs, and other kinds, as well as the ASCII text handled in the original protocol, the Simple Mail Transport Protocol (SMTP). In 1991, Nathan Borenstein of Bellcore proposed to the IETF that SMTP be extended so that Internet (but mainly Web) clients and servers could recognize and handle other kinds of data than ASCII text. As a result, new file types were added to “mail” as a supported Internet Protocol file type.
Servers insert the MIME header at the beginning of any Web transmission. Clients use this header to select an appropriate “player” application for the type of data the header indicates. Some of these players are built into the Web client or browser (for example, all browsers come with GIF and JPEG image players as well as the ability to handle HTML files); other players may need to be downloaded.

 

Internet Networks 

TYPES OF NETWORKS

  • Local area network, or LAN
  • Metropolitan area network, or MAN
  • Wide area network, or WAN

Personal Area Network

A personal area network, or PAN, is a computer network organized around an individual person within a single building. This could be inside a small office or residence. A typical PAN would include one or more computers, telephones, peripheral devices, video game consoles and other personal entertainment devices.

If multiple individuals use the same network within a residence, the network is sometimes referred to as a home area network, or HAN. In a very typical setup, a residence will have a single wired Internet connection connected to a modem. This modem then provides both wired and wireless connections for multiple devices. The network is typically managed from a single computer but can be accessed from any device.

This type of network provides great flexibility. For example, it allows you to:

  • Send a document to the printer in the office upstairs while you are sitting on the couch with your laptop.
  • Upload the photo from your cell phone to your desktop computer.
  • Watch movies from an online streaming service to your TV.

If this sounds familiar to you, you likely have a PAN in your house without having called it by its name.

Local Area Network

A local area network, or LAN, consists of a computer network at a single site, typically an individual office building. A LAN is very useful for sharing resources, such as data storage and printers. LANs can be built with relatively inexpensive hardware, such as hubs, network adapters and Ethernet cables.

The smallest LAN may only use two computers, while larger LANs can accommodate thousands of computers. A LAN typically relies mostly on wired connections for increased speed and security, but wireless connections can also be part of a LAN. High speed and relatively low cost are the defining characteristics of LANs.

LANs are typically used for single sites where people need to share resources among themselves but not with the rest of the outside world. Think of an office building where everybody should be able to access files on a central server or be able to print a document to one or more central printers. Those tasks should be easy for everybody working in the same office, but you would not want somebody just walking outside to be able to send a document to the printer from their cell phone! If a local area network, or LAN, is entirely wireless, it is referred to as a wireless local area network, or WLAN.

Metropolitan Area Network

A metropolitan area network, or MAN, consists of a computer network across an entire city, college campus or small region. A MAN is larger than a LAN, which is typically limited to a single building or site. Depending on the configuration, this type of network can cover an area from several miles to tens of miles.

A MAN is often used to connect several LANs together to form a bigger network. When this type of network is specifically designed for a college campus, it is sometimes referred to as a campus area network, or CAN.

Wide Area Network

A wide area network, or WAN, occupies a very large area, such as an entire country or the entire world. A WAN can contain multiple smaller networks, such as LANs or MANs. The Internet is the best-known example of a public WAN.

 

 

COMMUNICATION SWITCHING

A network consists of many switching devices. In order to connect multiple devices, one solution could be to have a point to point connection in between pair of devices. But this increases the number of connection. The other solution could be to have a central device and connect every device to each other via the central device which is generally known as Star Topology. Both these methods are wasteful and impractical for very large network. The other topology also can not be used at this stage. Hence a better solution for this situation is SWITCHING. A switched network is made up of a series of interconnected nodes called switches.

Types of Switching Techniques

There are basically three types of switching methods are made available. Out of three methods, circuit switching and packet switching are commonly used but the message switching has been opposed out in the general communication procedure but is still used in the networking application.

1) Circuit Switching
2) Packet Switching
3) Message Switching

Circuit Switching

Circuit Switching is generally used in the public networks. It come into existence for handling voice traffic in addition to digital data. How ever digital data handling by the use of circuit switching methods are proved to be inefficient. The network for Circuit Switching is shown in figure.

Types of Switching Techniques

  • Here the network connection allows the electrical current and the associated voice with it to flow in between the two respective users. The end to end communication was established during the duration of call.
  • In circuit switching the routing decision is made when the path is set up across the given network. After the link has been sets in between the sender and the receiver then the information is forwarded continuously over the provided link.
  • In Circuit Switching a dedicated link/path is established across the sender and the receiver which is maintained for the entire duration of conversation.

Packet Switching

In Packet Switching, messages are broken up into packets and each of which includes a header  with source, destination and intermediate node address information. Individual Packets in packet switching technique take different routes to reach their respective destination. Independent routing of packets is done in this case for following reasons:

  1. Bandwidth is reduces by the splitting of data onto different routes for a busy circuit.
  2. For a certain link in the network, the link goes down during transmission the the remaining packet can be sent through the another route.

Types of Switching Techniques

  •  The major advantage of Packet switching is that they they are used for performing data rate conversion.
  • When traversing the network switches, routers or the other network nodes then the packets are buffered in the queue, resulting in variable delay and throughput depending on the network’s capacity and the traffic load on network.
  • Packet switching contrasts with another principal networking paradigm, circuit switching, a method which sets up a limited number of dedicated connections of constant bit rate and constant delay between nodes for exclusive use during the communication session.
  •  In cases where traffic fees are charged, for example in cellular communication, packet switching is characterized by a fee per unit of information transmitted.

Message Switching

In case of Message Switching it is not necessary to established a dedicated path in between any two communication devices. Here each message is treated as an independent unit and includes its own destination source address by its own. Each complete message is then transmitted from one device to another through internetwork.

Types of Switching Techniques

  • Each intermediate device receive the message and store it until the nest device is ready to receive it and then this message is forwarded to the next device. For this reason a message switching network is sometimes called as Store and Forward Switching.
  • Message switches can be programmed with the information about the most efficient route as well as information regarding to the near switches that can be used for forwarding the present message to their required destination.
  • The storing and Forwarding introduces the concept of delay. For this reasons this switching is not recommended for real time applications like voice and video.

 

Network Routers

The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to. A router is located at anygateway (where one network meets another), including each point-of-presence on the Internet. A router is often included as part of a network switch.

A router may create or maintain a table of the available routes and their conditions and use this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. Routing is a function associated with theNetwork layer (layer 3) in the standard model of network programming, the Open Systems Interconnection (OSI) model. A layer-3 switch is a switch that can perform routing functions.

 

URL

 

A URL (Uniform Resource Locator, previously Universal Resource Locator) – usually pronounced by sounding out each letter but, in some quarters, pronounced “Earl” – is the unique address for a file that is accessible on the Internet. A common way to get to aWeb site is to enter the URL of its home page file in your Web browser’s address line. However, any file within that Web site can also be specified with a URL. Such a file might be any Web (HTML) page other than the home page, an image file, or a program such as a common gateway interface application or Java applet. The URL contains the name of the protocol to be used to access the file resource, a domain name that identifies a specific computer on the Internet, and a pathname, a hierarchical description that specifies the location of a file in that computer.

FOR EXAMPLE:

www.internetnotes.in/book/internet.txt

 

 

Transmission Control Protocol(TCP)

Abbreviation of Transmission Control Protocol, and pronounced as separate letters. TCP is one of the main protocols in TCP/IPnetworks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.

 

Search Engines

A search engine is a software program or script available through the Internet that searches documents and files for keywords and returns the results of any files containing those keywords. Today, there are thousands of different search engines available on the Internet, each with their own abilities and features. The first search engine ever developed is considered Archie, which was used to search for FTP files and the first text-based search engine is considered Veronica. Today, the most popular and well known search engine is Google.

for example:

google ,yahoo,bing etc

 

ISP 

An Internet service provider (ISP) is a company that provides customers with Internet access. Data may be transmitted using several technologies, including dial-up, DSL, cable modem, wireless or dedicated high-speed interconnects.

Typically, ISPs also provide their customers with the ability to communicate with one another by providing Internet email accounts, usually with numerous email addresses at the customer’s discretion. Other services, such as telephone and television services, may be provided as well. The services and service combinations may be unique to each ISP.

 

Top 5 Fastest and Affordable Internet Service Providers in India

 

BEAM Telecom

Don’t ever try to mention this name on any of the web forums in India , people surely are going to get ultra  jealous of you . Beam was one of the first ISP’s in India to provide high speed and affordable internet connections for home consumers. They have the best Internet plans in all of India and provide internet services through fiber optics only . The only negative point is that their services are only limited to Hyderabad currently . but they are planning to going nationwide in a few months. So keep looking out for them .

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ACT Broadband

ACT broadband is the parent company of Beam telecom and they offer even better plans internet services in comparison to beam . Also they provide services like IPTV , Digital TV and Analog Tv along with their Broadband connections (Fiber-to-the-home Technology) . They Ineternet plans actually offer double the FUP limit thanBeam , thats makes it even better than Beam here  . Currently ACT broadband is available in Bangalore , Nellore and Vijayawada .

YOU Broadband

You broadband is another great internet service provider in India , who operate in the major metropolitan cities of India . They provide bandwidth in excess of 10 Mbps for home customers and their pricing are even affordable .  Currently their services are limited to major cities like Ahmedabad , Bangalore , Chennai , Gurgaon , Hyderabad , Mumbai , Navi mumbai , Powai ,Pune ,Surat , Thane , Vadodara and Vishakapatnam .

HAYAI Broadband 

Hayai broad is a emerging name in the ISP business ,The company  is based in Mumbai and provides internet services in Mumbai and its suburbs . Currently there are already having many cities on their expansion map , which includes cities  like Delhi , Bangalore , Hyderabad , Ahmadabad , Kolkata and many more .

The specialty about Hayai is that they don’t impose any kind of FUP on their plans rather they allow customers to download responsibly and if a customer uses this to their advantage and downloads exceedingly , they consult with the consumer and ask them  to move to  a higher plan . While this seems justifiable but we need to see what their customers say about this .

Reliance Broadband

Reliance has been a long term player in the ISP business . while they have been trying to capture a larger share of the market . but they don’t have good plans to counter the new private players in the market . Although they do have some very reasonable Internet plans with great pricing . keeping in mind that reliance is available virtually everywhere , it makes it to the list of the ISP’s with fastest internet speed in India . Keeping the current entry of private players in the ISP business , Reliance has added many new internet plans to its existing portfolio  , the cheapest of which starts at Rs 999 per month .

That was a brief list of five major Internet service providers in India with the fastest speeds,  we hope to review some more emerging internet service providers in the future soon . If you find this post resourceful and helpful then don’t forget to subscribe to us through email and leave a word about us with your friends .