Internet+intranet+extranet+virtual+private+network+VPN

=3.3 Networks=

The Internet, in simplest terms, is the large group of millions of computers around the world that are all connected to one another. These computers are connected by  ·  ** phone lines ** · ** fiber optic lines ** · ** coaxial cable  ** · ** satellites  ** · ** wireless connections ** When you log on to the Internet you are given access to many of the other computers that are connected around the world. The //backbone// of the Internet consists of a powerful set of telephone lines capable of transferring data at a very fast rate of about 45 megabytes per second. The lines link metropolitan cities and include national access points or feeds. If you imagine a geographic map, they are equivalent major highways, explaining why the Internet is often referred to as the //Information Superhighway//. The backbone of the Internet is operated and maintained by various companies and organizations working cooperatively without centralized ownership. Redundancy is built into the backbone of the Internet so that if one or more major lines go down, traffic can be rerouted, much like a traffic detour when a highway is temporarily under construction. While this might slow Internet traffic, it will not ‘break’ the Internet. Every computer connected to the Internet is assigned a unique Internet Protocol (IP) address. When you point-and-click on a link, your browser sends out a request that is addressed to the website that houses the content you want. Routers along the way read the data packet’s address and relay it along the best route available. When the data packet arrives at the website, the server reads the request and sends the requested page back to your computer via a return address in the data packet: this is your computer’s IP address. The data packet is routed back to you (in actuality, several data packets) and your browser interprets the content and displays the page for you. In essence the Internet is akin to a highway filled with rushing data packets versus cars. An Intranet is the generic term for a collection of private computer networks within an organization. An intranet uses network technologies as a tool to facilitate communication between people or workgroups to improve the data sharing capability and overall knowledge base of an organization's employees. An Extranet allows public access to employees, customers, clients or partners. The extranet uses Internet protocols so users can navigate with a browser, but resides on the company's private server rather than on a public Internet server. Extranet access from the Internet can be controlled through various architectures that are password or username specific. In other words, areas of the extranet will be available according to password credentials. This limits users to extranet pages relevant to the business they might be conducting, while keeping other areas of the extranet private and secure. One very valuable application for an extranet is customer service. Online patches, upgrades, downloads, knowledge bases, and an interactive Help Desk are just a few examples of ways to serve a client base using an extranet. Extranet chat boards where customers help each other with company products can also build customer confidence and brand loyalty, while saving valuable human resources. Chat boards are also a rich source for potential future product and support development. Another resource an extranet can provide is the ability to create secure areas for interaction between an organization and its partners or resellers. Development, dissemination of marketing information and tools, data sharing, research, sales reports and more are all possible using an extranet environment. An extranet can also connect to other extranets through the common language of Internet protocols. This makes it invaluable to organizations involved in collaborative efforts and opens the door to greater creative opportunities. It is a network used by companies to connect users at different locations to the company intranet, a private network that only company employees or other authorized individuals can access. Remote access and site-to-site are two types of networks commonly in use. A VPN network uses a public network, such as the Internet, to connect a company's main office and satellite offices. It can also include telecommuting employees, who are working from home or another location one or more days per week. As a result, people can share information and work together without having to be in the same physical location. Disadvantage of a VPN is the fact that deployment requires a high-level of knowledge and understanding of such factors as public network security. VPN security requires password and data encryption. Another disadvantage is its availability and performance is difficult to control.
 * Internet **
 * What is the internet? **
 * How does the internet work? **
 * Intranet **
 * What is an intranet? **
 * Extranet **
 * What is an Extranet? **
 * Virtual Private Network (VPN) **
 * What is a VPN? **