Single Name Server Info

The Domain Name System: A Non-Technical Explanation – Why Universal Resolvability Is Important

What is the Domain Name System?

The Domain Name System (DNS) helps users to find their way around the Internet. Every computer on the Internet has a unique address – just like a telephone number – which is a rather complicated string of numbers. It is called its "IP address" (IP stands for "Internet Protocol").

But it is hard to remember everyone's IP address. The DNS makes it easier by allowing a familiar string of letters (the "domain name") to be used instead of the arcane IP address. So instead of typing 192.0.34.65, you can type www.icann.org. It is a "mnemonic" device that makes addresses easier to remember.

Translating the name into the IP address is called "resolving the domain name." The goal of the DNS is for any Internet user any place in the world to reach a specific website IP address by entering its domain name. Domain names are also used for reaching e-mail addresses and for other Internet applications.

What is universal resolvability and why is it important to users?

Think of the phone system . . . when you dial a number, it rings at a particular location because there is a central numbering plan that ensures that each telephone number is unique. The DNS works in a similar way. If telephone numbers or domain names were not globally unique, phone calls or e-mail intended for one person might go to someone else with the same number or domain name. Without uniqueness, both systems would be unpredictable and therefore unreliable.

Ensuring predictable results from any place on the Internet is called "universal resolvability." It is a critical design feature of the DNS, one that makes the Internet the helpful, global resource that it is today. Without it, the same domain name might map to different Internet locations under different circumstances, which would only cause confusion.

When you send an e-mail to your Aunt Sally, do you care who receives it?

Do you care if it goes to your Uncle Juan instead? Wait a minute…do you have an Uncle Juan? Then whose Uncle Juan received it? Do you care if it reaches Aunt Sally if you send it from work but my Uncle Juan if you send it from home?

Of course you care who receives it . . . that's why you wrote it in the first place. Whether you're doing business or sending personal correspondence, you want to be certain that your message gets to the intended addressee.

If at any point the DNS must make a choice between two identical domain names with different IP addresses, the DNS would not function. It would not know how to resolve the domain name. When a DNS computer queries another computer and asks, "are you the intended recipient of this message?", "yes" and "no" are acceptable answers, but "maybe" is not.

Where does ICANN come in?

This is where ICANN comes in . . . ICANN is responsible for managing and coordinating the DNS to ensure universal resolvability.

ICANN is the global, non-profit, private-sector coordinating body acting in the public interest. ICANN ensures that the DNS continues to function effectively – by overseeing the distribution of unique numeric IP addresses and domain names. Among its other responsibilities, ICANN oversees the processes and systems that ensure that each domain name maps to the correct IP address.

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More Interesting

The first requirement for a LAN, of course, is at least two computers. The most popular way of meeting this requirement is to have somebody else lug a computer over to your house. With today's prices, however, it's increasingly possible to own two (or more) computers. For the rest of this article, I'll assume you have two PCs available.

The second part of making a LAN is to have some method of hooking the computers together. The simplest way to do this is to connect a null-modem cable between the serial ports of the two computers. This costs under $10 but requires a fairly complex setup: a free serial port on both computers and software which supports this type of connection. Also, a null-modem cable limits your "network" to two computers. Odds are, you'd get more mileage out of connecting your PCs via a true local area network.