Computers

Disappointing NBN

It’s earlyish 2018, and the NBN should be here. In fairness, for some people it is.  I work with someone who really does get 100Mbs from their fibre-to-the-home service, but I also know people with no NBN service, or something substandard.

All that comes over as a bit mysterious and geeky, which is a reasonable response.  But we’re here to demystify things, and to help there’s a page with explanations for some of the terms here.

Lets start with the NBN itself – what is it and why do we need it?

Go back 15 years and many of us had a home phone. Mobiles were common, but data was expensive and you didn’t get a whole lot of call time for your money. So, the landline ruled. The phone in your house was connected to the local exchange by copper, sometimes aluminium wire either underground or draped over poles running along the street. You could still access the Internet of course. All you needed was a modem and enough nouse to make it work. Or a geeky neighbour or child.

The speed you could get depended on a lot of things – the modem (faster was more expensive) and the quality of metal making up your phone line. My first modem ran at 300 baud, my next modem could support 2400, and another model a few years after that claimed 56kbs, although 40kbs was more realistic.

Right, now what does that all mean? Well, baud is a measure of speed that you can transfer data. Since we’re not in an exam, we can say 300 baud is the same as 300 bits per second. OK, but it still doesn’t mean much, does it.

Let’s try this. You’re reading a book on your Kindle. Each page has about 400 words on it, and, on average, each word has about 6.5 characters including punctuation. That’s 2600 characters per page. Let’s say 2500 to cheat a bit and try for a nicer round number.  For a computer, a character has 8 bits, so a page comes to 20,000 bits.

At 300 baud each page will take almost 70 seconds to download. At 2400 baud it takes 8 seconds, at 40kbs (that’s 40,000 bits per second), half a second. To read a Harry Potter book, the speed isn’t much of an issue of course. If you want to download that beautiful photo of Sydney Opera House, it’s going to be over a million characters or 8 million bits. At 40kbps you’re going to have to wait three and a half minutes for it to appear on your computer screen. Even the fastest modem encouraged patience and small photographs!

Then came ADSL which stands for Asymmetric Digital Subscriber Line. Aren’t you glad you asked? Suddenly, you could get 256kbs instead of 40. Or 512kbs or even more if you had the money, because as the speed increased, so did the cost. At 256kbs, you Sydney photo took 30 seconds to downlooad, at a megabit (a million bits per second), it took 8 seconds.  That’s a lot better, but in the early days it wasn’t cheap. And, of course, people being what they are, the photos just kept getting bigger and more realistic. As if that wasn’t enough, video started to appear and we went back to waiting again.

Countries that had a phone network able to support ADSL, and everyone wanted to have it, eventually had the same three variants. Some countries with more sophisticated regulation had more options, but let’s start wit the basic 3 for now. The thing to remember about ADSL is that the upstream speed, the speed from your house to the Internet is, at most, one megabit. That’s not entitely true as we’ll see later, but be gentle for now, OK?

ADSL1 had a maximum downstream speed of 8Mbs or megabits per second. Downstream is data moving from the Internet to your computer. That maximum is restricted by the hardware in the ADSL modem and is defined by the ITU (International Telecommunications Union) in Geneva. Next is ADSL2, which is where the confusion starts. The maximum downstream speed for ADSL2 is 12Mbs, and contrary to what people say so often, almost no-one has ADSL2.  In the early days, for a while, yes. But rarely since then. The last of the common variants is ADSL2+ probably the worst named standard in the entire IT industry. And when people say they have ADSL2, this is actually what they have. It has a maximum downstream speed of 24Mbs, although you need to be within a kilometre of the exchange to get it.

That last sentence is important. When the distance to your local phone exchange is measured, it’s not stright-line distance, or even how far it is if you walk or drive. The distance that counts is the length of the phone line from your house to the exchange building. I had a colleague who lived 50m from the exchange. He could see it 2 houses away. Unfortunately, his phone line left the exchange and went in the opposite direction. He was actually over 2km from the exchange, not the 50m he expected.

When I lived in Perth, my house was 3500m from the exchange, the copper was reasonable quality but I could only get 5.5Mbs, less when it rained. Weather is important because when your phone line goes underground the conduits fill with water and, as we all know, water and electricity don’t mix. It’s not dangerous, a phone line only carries 12 volts, but it plays havoc with download speed.

Remember I said that the upstream speed was always one megabit? Well, you can increase that, and you do it by taking speed from the downstream part of ADSL. It’s not an equal swap though. To get 2Mbs upstream, you may have to halve the downstream speed. The reason is complex and ot something I don’t feel the need to go into here, but it relates to frequency allocation of upstream and downstream traffic.

OK, we’re firmly in the 21st century and just reached the stage of having NBN. When the Federal government supported the design for a new, faster network that was future-proofed, they got what they asked for. Optical fibre to every building with a guaranteed 100Mbs downstream and 50Mbs upstream if that’s what you wanted. Of course it was expensive – the Labour government estimated the cost to be in the region of $60 billion. The true cost would have been more than twice that of course – remember, this is government.

Shortly after the build started, the government changed and the new guys didn’t like the previous government’s network design. After all, who needs 100Mbs? No-one does. 25Mbs is quite good enough. So, existing build commitments would be honoured, but no new ones were allowed. Instead a new design put a new box at the end of each street – well, at the end of a nearby street. Optical fibre would run from the exchange to the box, and the old, sometimes fairly crummy copper would be used to your house. There were still promises of 100Mbs for people who really needed it, but I don’t know anyone who really believed it. 

The new approach wasn’t going to work for people in the Australian outback, so they would be given a satellite service. “Given” of course means “would pay for”. This new network would be loads cheaper and better than the Labour one. But it wasn’t as easy as the new government pretended. Thousands of these new boxes had to be built and electricity provided.  Thousands of kilometres of optical fibre laid and millions of phone lines connected up.  The cost kept increasing of course, so in those places where existing telcos had coax under the street, usually to deliver Foxtel, that would be used instead of building those difficult boxes, and the cost reduced again. Sadly, so did the quality of the connection for many of those people forced on to coax instead of fibre. It got so bad, that NBN Co blocked any more coax connections until they got the existing mess sorted out. This left households being promised firstly fibre to the house, then fibre to the curb, then fibre to the end of the street with copper to the house, then reuse of existing reliable coax under the street, and finally nothing for 18 months so that NBN Co could sort out their mess.

The current head of NBN Co has stated that people in Australia don’t need high speed internet and wouldn’t know what to do with it if it were available, and at least one minor politician agrees. Well, I know one person with 100Mbs to his house and has no idea what to do with it. On the other hand I also know a couple with the same speed who use it fully. There are companies that are able to build a business based largely on high speed Internet access.

The messages in Australia are firmly mixed. The NBN rolled out so far works for some but not for others, and still more people have no access at all with little hope of getting something for up to 18 months. Most of us can get ADSL of some kind at least, although I know of areas in Australia where even that isn’t available.

Currently, I have ADSL, and use ADSL1 for technical reasons. It gives me about 6Mbs most of the time which is adequate, but hardly exciting. I’ve been promised (threatened?) with a coax cable connection, but probably not for 12-18 months.

Fibre to the house would have been wonderful and future-proofed, but for the whole country, hideously expensive. What we have is mixed, mediocre and can’t be meaningfully upgraded.