By SCOTT DEWING
Published: July 2008

I’ve never been much good at remembering numbers: phone numbers, PIN numbers, prime numbers, alarm code numbers, my social security number. I’ve become so numbed by the ever increasing strings of numbers I need to remember that I don’t seem to be able to remember any of them. Computers, on the other hand, are very good at remembering and using numbers. In fact, that’s pretty much all they do. Although we see pictures and text on our computer screens every day, it’s just numbers behind all of this graphical representations of information. All the data stored on your hard-drive is a combination of zeros and ones. Although the software applications you use were written by a computer programmer in a human-readable programming language, it is run through a "compiler" that translates the program into machine-readable code that looks something like this:

0100001001111001
0111010001100101
0010000001101101
0110010100100001

The Internet is all numbers too. When you go to a website, such as www.ijpr.org, you are really going to a specific combination of numbers. In cyberspace this specific combination of numbers is referred to as an IP address. IP stands for Internet Protocol and along with its partner TCP (Transmission Control Protocol), it forms the dynamic-duo of TCP/IP that allows the millions of computers connected to the Internet to communicate with one another. In short, whether it’s information stored and displayed on your computer or the method by which that information is shared over the Internet, it’s numbers all the way down.

Every computer that communicates on the Internet has to have an IP address. When you use your web browser to go to www.ijpr.org, you are really going to a webserver with the IP address of 64.241.70.212 Luckily, you can just type the much more easily remembered name of a website rather than the IP address of the webserver that hosts that website. This is all made possible through an incredible and dynamic system known as the Domain Name System, or DNS. You may not know much about DNS or may have never even heard of it; but when you use the Internet, you utilize DNS all the time. DNS is what allows us numerically challenged users to easily get to where we want to go on the Internet. Without DNS, you would have to remember the specific IP address of every webserver you wanted to connect to and get information from. Without DNS you’d have to remember 64.236.24.12 in order to go to CNN.com and read the news or 17.251.200.32 to go to Apple’s website and check out the latest iPhone.

Conceptually, DNS is very simple: it’s a large, distributed database that translates human-readable domain names to machine-readable IP addresses. The process of translating a domain name to an IP address is often referred to as "name resolution." Name resolution occurs every time you go to a website or send an email to a friend. What makes DNS complex is its enormous scope. Consider the following factors: 1) there are billions of IP addresses and domain names, 2) domain names and IP addresses change daily, 3) new domain names are created daily, 4) there are billions of DNS requests made every day, 5) tens of thousands of people around the world are involved in the process of maintaining and updating DNS.

At the heart of DNS are a dozen or so very special computers called "root servers." The term "root" is highly appropriate because it is from these root servers that the hierarchical, distributed database of DNS blossoms throughout the Internet. Each root server contains the same vital information about Top Level Domains, or TLDs. You already know many of the most common TLDs. These are your .com, .edu, .gov, .net, .org, and so on. There are also approximately 244 country-specific domains, starting with .ac (Ascension Island), hitting .kz (Kazakhstan) in the middle and ending with .zw (Zimbabwe).

In addition to root servers, there are thousands of other important computers on the Internet called "name servers." Name servers have complete information about some part of a domain name space. Root servers know where the name servers that are authoritative for each TLD. When you type www.ijpr.org into your web-browser and hit the Enter key on your keyboard, you set off a chain-reaction of queries. With any given domain name query, root servers can provide the names and IP addresses of the name servers authoritative for the TLD the domain name is in. These top-level name servers can in turn provide a list of name servers authoritative for the second-level domain and so on. Each name server that is queried supplies information that gets you closer to where you want to go, or provides the answer itself. In the case of www.ijpr.org, you have the "." which is at the root of all domain name queries. After the "." comes .org, then ijpr.org, then finally www.ijpr.org. This entire process is made incredibly fast by a feature called "caching." Name servers cache information they gain from each query they process. The next time a name server receives a query for a domain name it already knows about, the query time is considerably shortened.

That’s DNS in a nutshell. Now, if someone would just come up with a global system similar to DNS for the telephone system so that I wouldn’t have to remember phone numbers or physically look them up or have to enter them into my Palm Pilot to assist me during the process of resolving a person’s name to their telephone number, I’d be eternally grateful.