Chapter 1

DEFINITION OF CASE TOPIC
The objective of our studies is to show the impact of the Information Technology in the Communications. Communication is the transfer of information, such as thoughts and messages. There are many ways to communicate. The basic forms of communication are by signs (sight) and by sounds. Before last century, the way people communicate with each other has evolved at a very slow pace. The reduction of communication to writing was a fundamental step in the evolution of society for writing permits the preservation of communications from the past. It marks the beginning of recorded history and the preservation of knowledge for the future.
The invention of printer by Johannes Guttenberg who printed the Bible in the 15th century facilitated the widespread dissemination of information. The invention of the telegraph, the radio, the telephone, television and satellite made possible instantaneous communication over long distances. All these inventions lead to the invention of the Internet more than three decades ago. The Internet has revolutionized the communications world like nothing before. It will facilitate the widespread of knowledge to the whole world. Therefore, no one should deny the importance of the Internet and the role that it will play for our future.
In our report we will take a look at the history of the Internet, how it was invented, the people who were behind its invention, its development, its future and the impact that it has on our society. At the end of our report, we hope you will see the great impact of the Internet in the area of Communications.

INTRODUCTION TO THE INTERNET

The Official Definition of the Term "Internet"
On October 24, 1995, the FNC unanimously passed a resolution defining the term Internet. This definition was developed in consultation with members of the internet and intellectual property rights communities. RESOLUTION: The Federal Networking Council (FNC) agrees that the following language reflects our definition of the term "Internet". "Internet" refers to the global information system that -- (i) is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ons; (ii) is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its subsequent extensions/follow-ons, and/or other IP-compatible protocols; and (iii) provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein

The Internet is a global network of networks enabling computers of all kinds to directly and transparently communicate and share services throughout much of the world. Because the Internet is an enormously valuable, enabling capability for so many people and organizations, it also constitutes a shared global resource of information, knowledge, and means of collaboration, and cooperation among countless diverse communities.

HOW THE INTERNET WORKS

Internet is a global collection of networks that connect together in many different ways to form the single entity that we know as the Internet. Internet is monitored and maintained in different ways. The Internet Society, a non-profit group established in 1992, oversees the formation of the policies and protocols that define how we use and interact with the Internet.

Every computer that is connected to the Internet is part of a network. For example, you may use a modem and dial a local number to connect to your Internet Service Provider (ISP). At APIIT, you may be part of a local area network (LAN), but you are still connecting to the Internet using Jaring, the ISP that APIIT has contracted with. When you connect to your ISP, you become part of their network. The ISP may then connect to a larger network and become part of their network. The Internet is simply a network of networks. The name internet comes from this idea of interconnected networks.

Most large communications companies in the United States have their own dedicated backbones connecting between various regions. In each region, the company has a Point of Presence (POP). The POP is a place for local users to access the company's network, often through a local phone number or dedicated line. Instead of having overall controlling network, there are several high-level networks connecting to each other through Network Access Points (NAPs).
In the real Internet, dozens of large Internet providers interconnect at NAPs in various cities, and trillions of bytes of data flow between the individual networks at these points. The Internet is a collection of huge corporate networks that agree to all intercommunicate with each other at the NAPs. In this way, every computer on the Internet connects to each other. All of these networks rely on NAPs, backbones and routers to talk to each other. Through this process, a message can leave one computer and travel halfway across the world through several different networks and arrive at another computer in a fraction of a second.

The routers determine where to send information from one computer to another. Routers are specialized computers that send your messages and those of every other Internet user speeding to their destinations along thousands of pathways.

A router has two separate, but related, jobs. (i) It ensures that information doesn't go where it's not needed. This is crucial for keeping large volumes of data from clogging the connections of "innocent bystanders." (ii) It makes sure that information does make it to the intended destination.

In performing these two jobs, a router is extremely useful in dealing with two separate computer networks. It joins the two networks, passing information from one to the other. It also protects the networks from one another, preventing the traffic on one from unnecessarily spilling over to the other. Regardless of how many networks are attached, the basic operation and function of the router remains the same. Since the Internet is one huge network made up of tens of thousands of smaller networks, its use of routers is an absolute necessity.

The National Science Foundation (NSF) created the high-speed backbone in 1987. Backbones are typically fiber optic trunk lines. The trunk line has multiple fiber optic cables combined together to increase the capacity. Fiber optic cables are designated OC for optical carrier, such as OC-3, OC-12 or OC-48. An OC-3 line is capable of transmitting 155 Mbps while an OC-48 can transmit 2,488 Mbps (2.488 Gbps). Compare that to a typical modem transmitting 56Kbps that ordinary Malaysians used for surfing you can see just how primitive we are.

Today there are many companies that operate their own high-capacity backbones, and all of them interconnect at various NAPs around the world. In this way, everyone on the Internet, no matter where they are and what company they use, is able to communicate to everyone else on this world. The entire Internet is a gigantic, sprawling agreement between companies to intercommunicate freely.

Every client system connected to the Internet must have a unique identifying number, called an IP (Internet Protocol) Address. The IP is the language that computers use to communicate over the Internet. A protocol is the pre-defined way that the Web browser of the user's PC used to talk to another computer.
To make it easier for us humans to remember, IP addresses are normally expressed in decimal format as a dotted decimal number like the one above. But computers communicate in binary form.

When the Internet was in its infancy, it consisted of a small number of computers hooked together with modems and telephone lines. You could only make connections by providing the IP address of the computer you wanted to establish a link with. A typical IP address looks like this: 212.143.34.70.This was fine when there were only a few hosts out there, but it became unwieldy as more and more systems came online. That is why Internet Protocol Version 6 is being developed.

The first solution to the problem was a simple text file maintained by the Network Information Center that mapped names to IP addresses. Soon this text file became so large it was too cumbersome to manage. In 1983, the University of Wisconsin created the Domain Name System (DNS), which maps text names to IP addresses automatically. This way you only need to remember http://dan.ultimasurf.com, instead of Geocities's IP address to access to our Web site.

All of the computers on the Internet are either servers or clients. The computers that provide services to other computers are called servers. And the computers that are used to connect to those services are clients. Internet servers make the Internet possible. There are Web servers, e-mail servers, News servers, FTP servers serving the needs of Internet surfers all over the world.

When you connect to http://dan.ultimasurf.com to access to our homepage, you are a user sitting at a client's computer. You are actually accessing the Geocities's Web server. The server finds the page you requested and sends it to you. Clients that come to a server do so with a specific intent, so clients direct their requests to a specific software server running on the server. If you are running a Web browser on a PC, it will want to communicate to the Web server on the server machine, not the e-mail server.

A server has a static IP address that does not change very often. A home PC that is dialing up through a 56Kbps modem has an IP address assigned by the ISP every time the user dials in. That IP address is unique for the user's session. It may be different the next time the user dial in. This way, an ISP only needs one IP address for each modem it supports, rather than one for each customer. ISPs obtain registered addresses either from the Internet Assigned Numbers Authority (IANA) or from their own service providers, and sublet to their clients.

Any server makes its services available using numbered ports -- one for each service that is available on the server. For example, if a server is running a Web server and a file transfer protocol (FTP) server, the Web server would typically be available on port 80, and the FTP server would be available on port 21. Clients connect to a service at a specific IP address and on a specific port number.

Once a client has connected to a service on a particular port, it accesses the service using a specific protocol. Protocols are often text and simply describe how the client and server communicate. Every Web server on the Internet conforms to the hypertext transfer protocol (HTTP).

Networks, routers, NAPs, ISPs, DNS and powerful servers all make the Internet possible. All this information is sent around the world in a matter of milliseconds! The components are extremely important in modern life -- without them, there would be no Internet. And without the Internet, life would be very difficult for many of us who need to communicate and get information instantly.

When you surf the Web, you use a domain name to do it. For example, the Uniform Resource Locator (URL) http://dan.ultimasurf.com contains the domain name of our web site. So does this e-mail address: wwwhwccom@yahoo.com. Every time you use a domain name, you use the Internet's DNS servers to translate the human-readable domain name into the machine-readable IP address.

Top-level domain names, also called first-level domain names, include .com, .org, .net, .edu and .gov. Within every top-level domain there is a huge list of second-level domains. For example, in the .com first-level domain there is: Google, Overture, Ultimasurf, etc.

Every name in the COM top-level domain must be unique. The left-most word, like www, is the host name. It specifies the name of a specific machine (with a specific IP address) in a domain. A given domain can, potentially, contain millions of host names as long as they are all unique within that domain. Whatever files that you upload to your server for your Web page are usually stored in the www directory.

DNS servers accept requests from programs and other name servers to convert domain names into IP addresses. When a request comes in, the DNS server can do one of four things with it:
1. It can answer the request with an IP address because it already knows the IP address for the requested domain.
2. It can contact another DNS server and try to find the IP address for the name requested. It may have to do this multiple times.
3. It can refuse to recognize the IP address for the domain you requested, and replace it with another IP address for a DNS server."
4. It can return an error message because the requested domain name is invalid or does not exist.
When a surfer types the URL http://dan.ultimasurf.com into the Web browser, the Web browser contacts a DNS server to get the IP address. A DNS server would start its search for an IP address by contacting one of the root DNS servers. The root servers know the IP addresses for all of the DNS servers that handle the top-level domains (COM, NET, EDU, MIL, ORG, etc.). The DNS server would ask the root for http://dan.ultimasurf.com, and the root would return the IP address for the COM DNS server which handles http://dan.ultimasurf.com.

Your name server then contacts the DNS server for http://dan.ultimasurf.com and checks if it knows the IP address for http://dan.ultimasurf.com. If it does, it will returns the IP address to your DNS server, which returns it to the Web browser, which can then contact the server for http://dan.ultimasurf.com to get a Web page.

One of the keys to making this work is redundancy. There are multiple DNS servers at every level, so that if one fails, there are others to handle the requests. The other key is caching. Once a DNS server resolves a request, it caches the IP address it receives. Once it has made a request to a root DNS server for any COM domain, it knows the IP address for a DNS server handling the COM domain, so it doesn't have to bug the root DNS servers again for that information. DNS servers can do this for every request, and this caching helps to keep things from bogging down.

Even though it is totally invisible, DNS servers handle billions of requests every day and they are essential to the Internet's smooth functioning.

CONNECTING TO THE INTERNET

Most home users connect to the Internet by subscribing to an Internet Service Provider (ISP). Typical ISPs allow customers to connect to the Internet using telephone lines. A user connects to an ISP by using an analog modem. The ISP then connects the user to the Internet. A modem takes digital signals from the computer and turns them into sound. The sound, which is an analog signal, can be transmitted over a telephone line. A modem at the ISP then converts the sound back into a digital signal that can be transmitted over the Internet. Users have to pay monthly fees to the ISP for Internet access. There are many ways to connect to the Internet through the ISPs. Among them are:
(i) Digital Subscriber Lines (DSL) offers high bandwidth Internet access over existing copper telephones lines. There are many types of DSL available, such as ADSL (Asymmetric DSL), SDSL (symmetric DSL), etc. In terms of bandwidth, DSL connections can offer transfer speeds of up to 55 Mbps.
(ii) Broadband is a category of high bandwidth Internet service provided mainly by cable television and telephone companies to home users at the download speeds between 384 Kbps and 1.5 Mbps and upload speeds of 128Kbps.
(iii) Integrated Services Digital Network (ISDN) provides high speed connections over both digital and standard telephone lines with transfer speeds of up to 128 Kbps.
(iv) WebTV is a low cost technology for connecting to the Internet through user's television instead of PC.

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