The BigLig Thinks

I love it because it makes finding out an obscure fact worth the effort.

I was just giving my standard explanation on what bandwidth is, and what latency is. I do this by using a piece of road as an analogy. And, thanks to google, I was able to refer to a specific road near where the victim of my explanation lives. (Which is in another continent).

My analogy, if you're interested, goes like this:

Bandwidth and latency are the two things that measure how “big” or "good" an network connection is.

The best way to think of them is to picture a stretch of road. Two things determine how “big” that stretch of road is – how long does it take any particular car to travel that section (which in network terms we call latency), and how many cars go over that section in an hour (which we call bandwidth).

If the city want to improve a road, latency is hard to change – they could maybe improve a junction so the cars go through it faster (in network terms, upgrading a router), or build a new bridge to shorten the route (rerouting), but it won’t help much.

Bandwidth is a bit easier to improve – you can add an extra lane. Another way that the city could improve things for some people (at the expense of others) is to add a carpool or bus lane - in network terms this is called QOS or traffic shaping.

Bandwidth and latency are sort of linked. As traffic increases, you fill up the road. Once the road is full (and how long this takes depends on the bandwidth), then the cars slow down, and so the latency goes up.

It's important to notice that latency is all that the users notice – you don’t care how many cars an hour go through a road, you care about how long it takes you to get to your destination.