When you communicate with ice.cream.org, you are communicating using TCP/IP. This is the protocol (or agreed set of communication standards) that makes the Internet tick. It stands for Transmission Control Protocol over Internet Protocol, and its job is to make sure that data gets from A to B in the right order. Because the Internet combines many interconnected machines, the data will move from A to B via a number of intermediate machines - like a pinball. It needs to find a route from A to B, and that process, unsurprisingly, is called routeing. But whole books can be written on how that is achieved. And indeed, they have. All you need to know at the moment is that, like the phone system, TCP/IP requires that every host connected to the Internet has a unique number, and so can be contacted from any other. In Europe, an organisation known as RIPE delegates these numbers.
Ice's world-unique
identifier number in standard decimal is If we convert this
unique identifier to 3272099614 to binary, we get As you know, computers like binary but this is rather unwieldy! So let's split it into four groups of eight binary digits (ie: four bytes), where each byte has the maximum combined value of 255. We'll separate each byte
with a dot And now let's covert
each separate byte back to decimal: What you see above is know as the IP address (or IP number, or dotted quad or any number of synonyms). |
Even when you dial up to your Internet Service Provider, your computer is given an IP number. Sometimes it will be a fixed IP number it is allocated every time it logs in (a static IP address, as it is known). More commonly, to save resources, the ISP has a pool of IP numbers, one if which is allocated to your computer at random when you dial up. Since, by reading these pages, you have made a connection to our web server, it is able to detect the IP number which you are currently assigned, which is: 18.188.76.161
Note that if you are browsing the web through a proxy server (your ISP might have set up your browser automatically so you are), then that is the IP address you will see above, rather than your own individual one. This is because the proxy is the machine that actually contacts ice.cream.org to suck down the web page, and your computer has made no direct connection to us :-)
IP addressing is actually more complex than this, because the numbers are delegated in a particular way, where one section of the total number signifies the whole destination network, and another signifies the specific host machine on that network, in the same way that a dialling code on a phone number signifies the country and/or city, and the rest of the phone number represents the actual phone that is required to ring.
Even in dotted quad format, it would be a pain if humans had to specify numbers to contact servers - we're linguistic animals and like words. Fortunately, our DNS information section illustrates how this is achieved.