Internet


Because it has such a strong impact on almost every other technology, the Internet may be the most important communication technology in the world. The Internet itself is only a few decades old, and in that short time, the internet has evolved from a technical curiosity to a major influence on nearly every aspect of life in developed countries. The Internet has become a social force, economic force, and a legal force
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Background:
“In the 1950s, the U.S. Department of Defense started researching ways to create a decentralized communications system that would allow researchers and government officials to communicate with one another in the aftermath of a nuclear attack. To them, a computer network seemed to be the most logical way to accomplish this. The Advanced Research Projects Agency (ARPA) was formed by the military to study ways to connect networks” (Comer, 1995). By 1969, four computers in California and Utah had successfully been interconnected by ARPA, creating what came to be called ARPANET. By 1975, there were about 100 computers connected to ARPANET, and by 1984, the number grew to 1,000 (Clemente, 1998). ARPANET became formally known as the Internet in 1983, and the number of computers connected to it continued to grow at quite a fast rate. (1)
Domain Name System
“The Domain Name System (DNS) is a hierarchical naming system for computers, services, or any resource connected to the internet or a private network” (domain name system, Wikipedia). DNS makes it possible to assign domain names to groups of Internet users, free of each user's physical location. With this, World-Wide Web (WWW) hyperlinks and Internet contact information are able to remain consistent and constant even if the current Internet routing arrangements change or the Internet user is using a mobile device. (2)

Each computer on the Internet has a unique IP allowing other computers on the Internet the ability to locate it. The IP address is a series of numbers separated by periods, such as 129.1.2.169; since these numbers strings are difficult to remember and have no relation to the information contained on the computers they identify, an alternate addressing method came into place called the domain name system (DNS) , which assigns text based names to the numerical IP addresses (i.e. personal.bgsu.edu). “Domain names are administered by a global, nonprofit corporation called the Internet Corporation for Assigned Names and Numbers (ICANN). Outside the U.S., computers are identified by country code top-level domains (ccTLD)” (Grant and Foust). For other countries, the last part of the domain name identifies the country, not a specific type of information. (I.e.-computers in Japan use the .jp ccTLD, while those in Canada use. ca) (1)

“The Domain Name System distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating authoritative name servers for each domain” (domain name system, Wikipedia). Authoritative name servers are individually responsible for their particular domains, and can assign other authoritative name servers for their sub-domains. These servers have made the DNS distributed, allowing it to be fault tolerant, while helping to avoid the need for a single central register to be constantly consulted and updated.

In general, the DNS also stores other types of information, such as the list of mail servers that accept email for a given internet domain. By providing a worldwide, distributed keyword-based redirection service, the Domain Name System is an essential component of the functionality of the internet.
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(1)
“The Internet and the World Wide Web.” Communication Technology Update and Fundamentals. Ch 18. Pg 268-271. 2008, Elsevier Inc.
(2) “Domain Name System.” Wikipedia: The Free Encyclopedia. 24 Oct 2009. http://en.wikipedia.org/wiki/Domain_Name_System


More on the background of the internet:
http://mason.gmu.edu/~montecin/internet-www.htm