INTERNE
- Interconnected physically.
- Capable of sharing & communicating data with each other.
- Able to act together as a single network.
Internet is a worldwide support group for any problem.
In 1969, The Department of Defense (DOD) of United States of America started a network called ARP net (Advanced Research Projects Administration Network) it began with one computer in california & three in Utah. Later, to share the hardware & software resources & then military allowed universities to join the network, from where the students caught up with it & developed much of the software, giving birth to Internet.
Internet uses the standard internet protocol suite to serve the billions of users worldwide. It has no centralized governance, so it uses extensive range of information resources & various services namely Inter-linked hypertext documents of www & the infrastructure to support e-mail. Today more than 100 coutries are linked with Internet to exchange data, near & various opinions
Development of Internet
1.In 1957 ARPA is formed with in the Department of Defense (DOD).
2. In 1969 A connection is made between The University of California Los Angeles and The Stanford Research Institute - Arpanet is born, created by the US Department of Defense Advanced Research Projects (Darpa)
3. In 1971 ARPAnet consisted of 23 hosts & the first virus - Creeper was created
4. In 1973 ARPAnet consisted of 35 hosts.
5 In 1974 Vint Cerf & Bob Kahn came up with an idea of connecting dissimilar network with one another in their research paper.
6. In 1978 400 Arpanet users receive the first ever spam email inviting them to a product demo & then US National Science Foundation creates a non-military network for American universities.
7. In 1979 Arpanet user Kevin Mackenzie uses the emoticon.
8. In 1982 TCP/IP Protocol suite is choen to a standard for ARPAnet. Internet is born.
9. In 1983 ARPAnet was dissolved in to ARPAnet & MIL.net.
10. In 1986 National Science Foundation(NSF) connected its huge network of 6 super computer centers to ARPAnet.
11. In 1989 govt. gave the permission to non-profit companies to join NSFnet through the backbone.
12. In 1990 ARPAnet was shutdown & then ANSNET was formed.
13. In 1991 NREN was formed. Tim Lee at CERN introduces the World Wide Web. 14 In 1993 Mosaic web browser launched.
15. In 1994 Webcrawler, go.com and Lycos search engines launched & also Yahoo! founded.
16. In 1995 NSFnet was then discontinued & ANSNET was sold to America Online Microsoft launches Internet Explorer. Amazon and eBay founded
WORKING OF INTERNET
Internet is an interconnection of large number of heterogenous computer network all over the world. Whenever a user wants to send data from one computer to another computer on the internet then this data is broken down in to small pieces & these small pieces are known as packets. Each & every packet contains the data,address of the sender & receiver.The address of sender & receiver is known as IP address. IP address for each computer that is
connected to the internet is unique. When a packet is sent across a network then it may follow one or more networks to reach the computer at the destination network & the process of selecting the most appropriate network over which this packet is to be sent is decided by the router A router is a network connectivity device that works at the OSI network layer & it can link two or more networks segments & it performs the task,to route packets between them When packet arrives at the router,then it examines the destination address of the packet it receives & then sends it across another network along the fastest available path. When packet arrives at the destination, they may not be in a desired sequence, so the destination computer then reassembles the packets using the sequence number stored in each packet in to a message.
Packet switching is method of communication between computers in a network in which blocks of messages to be transmitted are formed into packets & placed on the channel, & each packet contains source & destination address, synchronizing, error correction & the control bits. The protocol that helps to define the packet switching technique on the internet is called TCP/IP i.e. Transmission Protocol/Internet Protocol. TCP/IP allows different types of networks & computer system to communicate with each other. When computer sends a message to another computer across the internet firstly it connects to a small local ISP thriugh a modem. Local ISP provides internet services with a network thatsupplies services to its own employes Then these local ISP's are connected to regional ISP's which operate at the regional level.ISP's Regional network consists of interconnected routers in the various cities served by the ISP then these ISP's are connected to National ISP's, which when interconnected together from the Internet backbone & they are called Network Service Providers(NSP's). NP exchange data with other NSP's through the complex switching station called Network Access Points (NAP's) & Meteropolation Area Exchanges(MAE'S)
INTERNET IN INDIA
On 15 Aug 1995 Videsh Sanchar Nigam Limited (VSNL) started a service called Gateway Internet Access Service (GIAS) to allow the Indian users to access Internet. Satyam, VSNL, MTNL, GLIDE, SIFY etc. are some Indian Internet service providers (ISP). Some popular Indian ISP's are given below in Table 1.
There are two ways to get connected to the Internet via phone lines. These are given below:-
1. Conventional dial up/shell account.
2. Protocol dial up (TCP/IP) Account.
In conventional dial up we establish an Interactive session with another computer which is an
Internet host. The remote computer becomes our home base for working on the Internet.
Above Fig. 1 shows conventional dial up method. Following accessories are needed to establish a conventional dial up & these are given below:-
1. A home telephone.
2. A modem.
3. A Computer with a serial port for external modems or an expansion slot for Internal Modems.
4. Communication S/W.
5. An account with VSNL.
Where as in portocoldial up we can establish a phone connection with a computer attached the Internet, our home computer exchange portocol information with the remote computer to becme a fullfledged Internet host while we are dialled in. In this type of connection our desktop computer becomes the base of operations for using the Internet.
Above fig 2. shows the protocol dial up following accessories are needed to establish a Protocol dial up & there are given below:-
1. A Home Telephone.
2.A Modem.
3. A computer with serial port for external modem or an expansion slot for Internal modem.
4. Communication s/w.
5.S/w for SLIP or PPP.
6. A SLIP/PPP account with VSNL
INTERNET ORGANIZATIONS & COMMITTEES
Various Internet organizations & committes associatted with Internet are given below:-
1. ISOC: ISOC stands for Internet Society is a non governmental international organization. ISOC promote global co-operation & co-ordination for Internet technologies & its applications.
2. IAB: IAB stands for Internet Architecture Board. It is advisory group of the ISOC. IAB appoint new IETF & IESG candidates & also it provides services to the Internet Society.
3. IESG: IESG stands for Internet Engineering Steering Group & it provide technical management of IETF activities.
4. IETF: IETF stands for Internet Engineering Task force. It is open international community of network designers, operators, vendors etc. It provides technical & development services for the Internet.
5. IRTF: IRTF stands for Internet Research Task force. It is used to create research groups that focus on Internet protocols, architecture, applications & technology.
6. IAHC: IAHC stands for International ADHOC Committes. It is an international multiorganization effort for specifying & implementing polocies & proceduers relating to DNS.
7. IANA: IANA stands for Internet Assigned Numbers Authority. It is used to assign Internet protocols parameters such as address, domain name.
8. INTERNIC: INTERNIC stands for Internet Network Information Center. It provides domain name registration & IP network.
9. W3C: W3C stands for worldwide web consortium. It is responsible to maintains vendors neutrality & works with the global community to produce software that is made freely available throughout the world.
10. FNC: FNC stands for Federal Networking Council. It is a membership consists of one representative from 17 U.S federal agencies.
INTERNET SERVICE PROVIDERS
ISP is an organization that provides the Internet of facility to consumers & related services. ISP charges users a fee & in return, provides them with a phone number & computers account which will enable them to connect to the Internet.
Types of ISP
1. Online Companies: America Online & Prodigy are famous online companies IPS. They provide local access number. Software provided by major online services is easy to set up & use.
2. National Access Providers: AT & T. Earthlink, Netcom are National Access ISP. They operate nation wide with local access number.
3. Local Access Providers: They operate locally or they are located in town.
INTERNET ADDRESSING
There are only two types of address namely:-
(1) Domain Name System
(2) IP Address.
1. Domain Name System: Domain Name system is a hierarchical, distributed way of organizing the name space of the Internet. DNS is used to convert domain names into IP addresses. No two organizations can have the same domain name. Domain Name Servers are the hosts & programs which answers DNS protocal queries. A domain name is always contains two or more components separated by periods called "dots" for example microsoft.com. Each domain name corresponds to IP address. An IP address takes the form of 4 number, each one resides between 0 to 255 separated by 255 periods.
The Internet naming structure is organized in a logical hierarchy of domains is called Domain Name Space; & the domain name space is organized as an inverted tree with the root at the top. The hierarchy consists of multiple levels ranging from level 0 to 127 Below fig, shows a part of Internet Domain Space.
The DNS arranges host names in a hierarchical fashion and the top domains in the hierarchy is called top level domains & there are only two types of top level domains and these are
given below:-
1. Non-geographical Domains.
2. Geographical Domains,
Non-geographical domains are those which indicate the type of organization some of the standard for Non-Geographical Domains (Top Domains) are given :-
1. Com: Used for commerical organization for example www.google.com
2. Gov: Used for governmental agencies for example www.incometax.gov.
3. Net: Used for Network provider (ISP's) for example www.vsnl.net
4. Edu: Used for educational Institution for example www.mdu.edu.
5. mil: Used for military organizations for example www.dod.mil
Geographical domains indicate the code for individual countires. Some of the standard for
geographical domains are given below:-
1. In. for India
2. AU for Australia
3. UK for U.K..
4.CH for Switzerland
5. GE. for Germany
Characteristics of Domain Name
1. Up to 26 Characters long.
2. It contains of letters, numbers & hyphens.
3. Cannot have spaces.
4. Cannot begin or end with a hyphen
IP ADDRESS
IP address stands for Internet Protocol address. It is a set of numbers that specifies the location of a computer on the Internet. IP address is also known as IP Numbers & Internet addresses, An IP address consists of four major sections seperated by ".". Each sections consists of range 0 to 255 for example 202.54.1.7. These four sections represent both the machine itself, or host & the network that the host is on. The network area of the IP address is allocated to ISP by Inter NIC, Under the authority of IANA which stands for Internet Assigned Numbers Authority. After this ISP assign the host portion of the IP address to the machines on the networks that they operate. Static & Dynamic IP addressing are used by networks. In static IP addressing computer uses the same address every time when a user log on to a network. Where as in Dynamic IP address is assigned to a system (computer) usually by a remote server which is acting as a Dynamic Host configuration Protocol server (DHCP). IP addresses assigned using DHCP may change depending upon the address available in domain.
1. Network Id(Net Id) or Network Address.
2 Host Id or Host Address.
Net Id identifies uniqueley each network from other networks on the internet whereas Host Id uniqueley identifies each machine on the network to which information should reach. The network address is made up from higher order bits of the IP address & the host address constitutes the rest.
Below fig. shows the representation of IP address.
Class Type Net Id Host Id
<..........................32 Bits.......................>
Fig. Representation of IP address
Due to the growth of Internet, 32 bits that are reserved for IP address were not sufficient to handle all the potential networks & host connected to it. So Internet community decided to create addressing schemes & these addressing schemes discussed below.
ADDRESSING SCHEMES
There are five different addressing schemes & these are given below:-
1. Class A: This scheme is assigned to networks with a very large number of hosts. It utilize 7 bits in the first byte to define the network IP of the address. The value of the first byte for Class A addresses ranges from 0 to 127 & the remaining 3 bytes define the host IP. It supports 126 networks & approx. 17 million host per network.
2. Class B: This scheme is assigned to medium sized to large sized networks. It utilizes 14 bits in the first and second bytes to define the network ID portion of the address. Address in Class B ranges from 128 to 199. The host ID is define in last two bytes it supports 16,384 networks & approx. 65000 host per netowork.
3. Class C: This scheme is assigned to LANs it utilizes 21 bits in the first three bytes to define the network ID portion. Address in Class C ranges from 192 to 223 & the last ID defines the host ID. It supports approx. 2 million networks & 254 host per network.
4. Class D: This scheme assigned for multicasting to a number of hosts.
5. Class E : This scheme is assigned for experimental addresses & it is reserved for future use.
Characteristics of IP address
1. IP addresses are unique.
2. No two systems can have same IP Number.
3. IP address are global & standardized.
INTERNET TOOLS
Internet uses various tools for communication & some of the Internet tools are given below:-
1. E-mail: E-mail stands for electronic mail. It is the Internet's most widily used feature E- mail is a private communication between two or more hosts who have accounts on the Internet. It is much like regular mail but it is faster. An e-mail address is also similar method to send messages from one system (Computer) to another. An e-mail is made up of two parts namely:-
1. The address. 2. The message
POP 3 (Post Office Protocol Version 3), SMTP (Simple mail transfer protocol) UUCP(Unix to Unix copy protocol) etc. are some popular E-mail protocols.
2. FTP: FTP stands for file transfer protocol. It is used to transfer files between hosts. It is a part of TCP/IP protocol suite. It works or client/server phenomena. A client program enables the user to interact with a server in order to access information & services on the server. Files that are to be transferred are stored on computers FTP servers; to access these files, a FTP client program is used. There are three software packages used in FTP & these are:-
1. Cute FTP. 2. FTP Explorer
3. Elite FTP
3. Telnet: Telnet stands for Tele Communication network Telnet is the ability to access & control another computers somewhere on the Internet. It is widely used to access databases & explore public access computer systems. Telnet can connect to a remote machine that on a network and is port listening. Some common ports are given below:-
1. Port 21 FTP
2. Port 22 SSH Remote Login
Protocol
3. Port 23. Talnet Server
4. Port 25. SMTP (Simple Mail
transfer Protocol)
5. Port 53. DNS (Domain Name
Server)
6. Port 69. TFTP (Trivial File
Transfer Protocol)
7. Port 70. Gopher
8. Port 80. HTTP (Hyper Text
Transfer Protocol)
9. Port 110. POP 3 (Post Office
Protocol 3)
4. Gopher: Gopher is a software tool that connects a variety of computers & information archieves on the Intenet. It was orginally developed at the University of Minnesota as a Campus-Wide Information System (CWIS) but it was quickly caught on as a way for anyone on the Internet to publish information & organize network resources.
5. Veronica: Veronica stands for very Easy Rodent Oriented Net-wide Index to computer Archives. It is a companion tool to gopher. It searches goopher space.
6. Archie: It is Internet search program FTP archieves on the Internet. It is accessible through both Telenet & e-mail. It run as a client program & allow us to retrieve public domain files.
7. WAIS: WAIS stands for wide Area Information System. It helps to locate text documents. The seach is based on the keyword provided. WAIS keep track of how many times the keyword is found in docuements.
8. Newsgroups: Also known as USENET. It is global bullet in board service that uses the Internet as an access point. It is International meeting place.
HARDWARE REQUIREMENT FOR INTERNET
1. An account with an Internet Access provider.
2. A telephone connection.
3. A computer with serial port or expansion slot.
4. A modem.
SOFTWARE REQUIREMENT FOR INTERNET
1. Commuication Software is needed.
2. Web browser needed. Netscape navigator, Microsoft Internet Explore are some popular web browser.
3. FTP & IRC software.
INTERNET APPLICATIONS
There are various Internet Applications some of these application are given below :-
1. WWW: www stands for world wide web. It is multimedia experience on the Internet. www allow us to create links from one piece of information to another.
2. E-mail: E-mail stands for electronic mail. Today millions of people are connected to the Internet & they can sends & receive e-mail. An e-mail message is not limited to text only. because attachements are also possible in e-mail.
3. FTP: FTP stands for file transfer protocol. FTP is used to transfer files between computers on the Internet. Anonymous and non-anonymous are two FTP connections. There are also two types of file transfer namely ASCII and Binary. ASCII is used for text transfer only where as binary transfer any type of data.
4. IRC: IRC stands for Internet relaychat. It is a place where to meet people on the net. It provides real time communication with others on the Internet.
5. Use net: It is a collection of more than 15,000 news group on every subject.
6. Telnet: Telnet stands for tele communication network. It is a protocol that enables one computer to connect to another computer. This process is known as remote login. Hytelnet is a tool that helps us to access the various sites through Telnet.
7. Telephony: It is the technology associated with the electronic transmissionof voice, fax ete between distant parties.
8. Tele Conferencing: Tele conferencing is a meeting in which the participants do not meet physically but use telephones & computers to meet.
9. Video Conferencing: Video Conferencing involves sending video signals. It requires special hardware. allows users to work
10. Collaborative Multimedia Computing: This Internet application together on documents & projects, usually in real time.
ADVANTAGE OF INTERNET
1. Faster Communication: The foremost target of Internet has always been speedy communication and it has excelled way beyond the expectations. Newer innovations areonly going to make it faster and more reliable. Now, we can communicate in a fraction of second with a person who is sitting in the other part of the world. For more personal and interactive communication, we can avail the facilities of chat services in video conferencing. With the help of such services, it has become very easy to establish a kind of global friendship where we can share our thoughts and explore other cultures.
2. Information Resources: Information is probably the biggest advantage that Internet offers. Internet is a virtual treasure trove of information. Any kind of information on any topic under the sun is available on the Internet. The search engines like Google, Yahoo are at our service on the Internet. There is a huge amount of information available on the Internet for just about every subject known to man, ranging from government law and services, trade fairs and conferences, market information, new ideas and technical support, the list is simply endless.
Students and Children are among the top users who surf the Internet for research. Today, it is almost required that students should use it for research or the purpose of gathering resources. Even teachers have started giving assignments that require extensive research on the Internet. Besides, we can access to latest researches in the field of medicine, technology and so on. Numerous web sites such as America's Doctor also allow you to talk to the doctor online.
3. Entertainment: Entertainment is another popular reason why many people to surf the Internet. In fact, the Internet has become quite successful in trapping the multifacted entertainment industry. Downloading games or just surfing the celebrity websites are some of the uses people have discovered. Even celebrities are using the Internet effectively for promotional campaigns. Besides, there are numerous games that can be downloaded for free. The industry of online gaming has tested dramatic and phenomental attention by game lovers.
4. Social Networking: One cannot imagine an online life without Facebook or Twitter. Social networking has become so popular amongst youth that it might one day replace physical networking. It has evolved as a great medium to connect with millions of people with similar interests. Apart from finding long-lost friends, we can also look for job, business opportunities on forums, communities etc. Besides, there are chat rooms where users can meet new and interesting people.
5. Online Services: The Internet has made life very convenient. With numerous online services we can now perform all our transactions online. We can book tickets for a movie, transfer funds, pay utility bills, taxes etc., right from our home. Some travel websiteseven plan an Itinerary as per our preferences and take care of airline tickets, hotel reservations etc.
6. e-commerce: The concept of e-commerce is used for any type of commercial maneuvering or business deals that involves the transfer of information across the globe via the Internet. It has become a phenomenon associated with any kind of shopping, business deal etc. Websites such as eBay allow us to even bid for homes, buy, sell or auction stuff online.
DISADVANTAGE OF INTERNET
1. Theft of Personal Information: If you we the Internet for online banking, social networking or other services, we may risk a theft to our personal information such as name, address, credit card number etc. Unscrupulous people can access this information through unsecured connections or by planting software and then use our personal details for their benefit. Needless to say, this may land us in serious trouble.
2. Spamming: Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system. Such illegal activities can be very frustrating for us as it makes our Internet slower and less reliable.
3. Virus Threat: Internet users are often plagued by virus atacks on their systems. Virus programs are inconspicuous and may get activated if we click a seemingly harmless link.Computers connected to the Internet are very prone to targeted virus attacks and may end up crashing.
4. Pornography: Pornography is perhaps the biggest disadvantage of the Internet. Internet allows us to access and download millions of porngraphic photos, videos and other X- rated stuff. Such unrestricted access to porn can be detrimental for children and teenagers. It can even play a havoc in material and social lives of adults.
5. Social Disconnect: Thanks to the Internet, people now only met on social networks. More and more people are getting engulfed in virtual world and drafting apart from their friends and family. Even children prefer to play online games rather than going out and mingling with other kinds. This may hamper a healthy social development in children.
Thus, the Internet has the potential to make your life simple and convenient, as well as wreak havoc in our life. Its influence is mostly dictated by the choices our make while we are online. With clever use, you can manage to harness its unlimited potential.
6. Rip-off Traders: Individuals who take money for a product, or offer to trade an item but don't produce the promised item.
