Bandwidth - how to understand it.

It's been a long time coming - but here's the first of a long list of best analogies I use to explain fundamental technology principles to the technophobes among us. First off in the list: Bandwidth

The more bandwidth you have, the more information you can push from point A to point B. Bandwidth determines how fast you download a movie, how easily you can stream Netflix, how fast Facebook loads on your phone or how quickly you can send and receive photo's. Bandwidth is a giant, fundamental part of everybody's life in this day and age - and despite how much people like to think they don't need to know about 'this techy stuff' - it will benefit you exponentially to realise how and what bandwidth is. Here's how it works.

Think of bandwidth as roads.
You're moving house. You have a tonne of stuff. Or twenty tonnes.
You want to move all of your stuff from Brisbane, to Sydney.
The larger your car, or truck, the more stuff you will be able to carry in 1 trip.
The more lanes the road has, the more trucks you can use to carry multiple loads at once.
The better the roads, the smoother that drive of information is.
The better the roads, the less likely a truck will hit a pothole, and lose some stuff out the back.
When roads intersect with other roads, traffic slows down, including your trucks.
There's no speed limit on these roads - speed is determined by the smoothness of your roads
Speed is also determined by the lack of intersections or lane reductions
Too much traffic, like real life, can cause congestion and traffic jams.
Traffic jams occur on smaller roads easier, or with poor quality roads.

Now in the above list of obvious information - replace 'stuff' with 'packets of information' - data you are trying to get from point A to point B. Replace 'intersections' with 'interference'. Replace 'traffic jams' with 'network congestion'.

When talking about how many lanes a road is, we're talking about how much 'bandwidth' you have available. This bandwidth flows two ways - downloading (information coming in) and uploading (information you are sending someone else).

When you try and load a Facebook page on your mobile, that is mostly downloading information from Facebook servers on to your device. The more bandwidth you have, the more information can be loaded at once onto your phone so you see the information quicker. The lower your latency, the more 'responsive' your page will be.

Same goes with Netflix. The higher your bandwidth, the less time buffering you will face, and the higher your quality of streaming resolution will be.

Some roads are high quality but very small, so only 1 car can fit through at a time, but it can go very fast. This is equivalent to low-latency connections but also low bandwidth. This is actually good for gaming, as gaming doesn't require good bandwidth (contrary to popular belief) - it requires low latency so that when I press a button, actions happen quicker in whatever server-world I'm connected to.

Other roads are high-bandwidth, but high-latency. This is equivalent to many lanes of trucks being able to carry a lot of information, but it takes a while for it all to get from point A to point B. This is good for downloading big files, movies, TV series etc -- as you will still be able to download fast, it just takes a bit to get going. This is not good for gaming, as high-bandwidth high-latency doesn't speed up responsiveness in the gaming world.

Congestion occurs when you have heaps of cars trying to use the same highway and trying to merge on at once, or change lanes. This results in super slow (almost crawl-like) moving traffic - and can essentially kill a network. Optus have many instances of congestion right now - as they continually incorporate more and more subsidiaries and off-branch el-cheapo phone networks to use their single network for all of them.

In Australia, ADSL/ADSL2+/VDSL is equivalent of generally single laned roads with potholes and quickly degrading infrastructure and a tonne of intersections. The closer you live to where you're trying to get to, the less intersections you face and the less potholes there are to slow you down. Even if you only live a few hundred metres away though, this is a pretty miserable road trip.

HFC (AKA Cable) is a 10-lane super highway one way (downloads) and a smooth 1-lane highway the other way (upload). Vastly superior to ADSL, with higher bandwidth AND lower latency - but it would be nice to have both ways opened up.

NBN is now a mixed bag of 10-lane highways one way (download), and 4-lane highways the other way (uploads), turning into off ramps made of potholed filled single laned off-ramps (Fibre to the Node) or having that highway go right into your living room (Fibre to the Premises).

Obviously, as many lanes as possible to and fro on the best quality roads possible to enable as many trucks as possible to carry as much cargo as possible at the highest possible speed, is ideal. High-bandwidth low-latency networks exist on HFC and NBN FttP, but the fastest in Australia right now is actually 4GX with Telstra. Where NBN FttP and Cable are limited to 100mbps downloads, I recently speedtested 206mbps download in my closed room in suburbs in real-life.

Also 5G launches next year, which will essentially reduce intersections, add lanes in both directions and make the roads even smoother for all mobile users. Unfortunately, right now, to use these roads is expensive. $150 per month will only net you 80GB of uncapped, full-speed road use with 4GX, whereas for $110 you can enjoy full speed 100mbps/40mbps NBN with 1000+GB of data.

Hopefully this has cleared up some people's perspective on what Bandwidth is, and how it relates to your internet usage and speed. Did it help you? Comment below to let me know if you have any questions.

Thomas Schipke7 July 2017