In this instalment of “MegaBites,” we will look at the Internet. This seems the most logical place for this column to find itself since my work is focused on web development, which, of course, would not be here if it was not for the Internet.
So, as promised in last week’s column, we will use an analogy to get us going on our discussion.
The best comparison to try to understand the structure and purpose of the Internet is to think of it as a large highway system, something like the U.S. inter-state one.
In tech-speak, we would talk about packets of information being directed from their source to their destination by routers. If we look at a highway, we see a bunch of vehicles (these will serve as our packets) going from point ‘A’ to point ‘B’ by driving down some different roads, taking a turn here and there, until they finally get to where they want to go.
Our highway system, where we have all these vehicles sharing the roads, seems quite common place, but it is this sharing of our transmission medium, our highway, that was the major breakthrough that made the Internet possible.
If we stick to our highway analogy, we can look at the pre-Internet era in this way. Say we wanted to drive from Fort Frances to Winnipeg. To do this, we would have to make sure the road all the way from here to Winnipeg was clear of traffic (i.e., not a single car on the road the whole way).
We then would start our drive, making sure the road was closed the entire time that we were driving so no other cars were on the road at the same time as us.
We can see that this is not the most efficient use of our resource. If we wanted to allow more people to drive between Fort Frances and Winnipeg at the same time as us, our only solution would be to build more roads.
What the Internet allows us to do is build a few big roads and let a whole bunch of people share the roads. But there is a little more to it than that.
You will remember above that we mentioned routing. Well, think about our drive to Winnipeg where we had the road all to ourselves. Suppose we came upon a bridge that was washed out? The first thought that comes to mind is to find another road that crosses the river and get to Winnipeg another way.
Prior to the Internet, though, what would have happened is we would have just turned around, gone home, and waited for another road to become available to us.
Packet routing on the Internet now allows selecting a different route in the event our primary one becomes unavailable.
While this all might seem like common sense when we talk about highways, you might already have guessed at the main challenge when it comes to communications. Sharing our transmission lines and routing vast numbers of packets requires a lot of decision-making that has to happen very fast.
Enter computers. As computers became cheaper and faster, they provided a means of managing all this data.
Troy L’Hirondelle is a programmer and systems administrator at Times Web Design.