In this week’s column, I will talk a little bit more about a topic that came up in the last column, namely packets.
As you will recall, we saw that the idea of breaking up information into small packets allowed communications networks to be used much more efficiently and reliably through network infrastructure sharing and routing.
If we take a closer look at how these packets work, we come to another important topic in communications technology and that is protocols.
Anyone who has ever surfed the web probably has noticed the http:// that appears in the address bar of their web browser.
This is an acronym for Hyper Text Transport Protocol, which is the protocol used by web servers and browsers to request and transmit web pages. The purpose of a protocol such as HTTP is to describe the structure of the packets that computers send back and forth to one another.
Each packet will have a header section that contains information about the packet, and a data section that contains the actual information we are interested in.
How the information is arranged in the header is defined by standards organizations such as the IEEE and ISOC.
Standardization is very important for protocols because without it, it would be impossible for computers to share information since there would be no way to tell what the information in the packet meant.
Imagine you were given a piece of paper with a whole bunch of text on it. No words or paragraphs or any sort or organization, just a whole bunch of random text.
You probably would just crumple it up and throw it in the garbage because it didn’t mean anything and nothing much would happen.
Now suppose you were given that same piece of paper, along with a handbook that described what all that text on the paper meant. Suppose your handbook told you that if the first character on your piece of paper was a ‘p,’ then it meant that you were to paint your car.
And if the second character on the page was a ‘b,’ then you were to paint your car blue. And so on and so forth, you could decode the message in this way.
So instead of nothing happening when you got that piece of paper, you now have a shiny blue car.
In a similar way, these protocols tell computer programs how to process what otherwise would be a bunch of meaningless data.
And what can you take away from all this?
Rather than looking at the Internet as a collection of computers, wires and fibre optic cables, and servers and so on, its real essence is a collection of ideas developed by people sharing ideas and putting those ideas down on paper.
Troy L’Hirondelle is a programmer and systems administrator at Times Web Design.