Sunday, 5 July 2009

What Speed Should I Be Getting?


One of the most commonly asked questions on the various Forums that deal with broadband in the UK (look in the panel to the left for some of these) is: "What speed should I be getting?" Although the quick speed check tools like the one above are excellent for day-to-day use, they have limitations that make them unsuitable for more detailed data collection.

Well, to get a better understanding of your speed, the obvious starting point is to double-check your contract. What have you actually signed up for? Surprisingly, when DSL-Max came along, many people didn't sign up for it and still remain on 500kbps or 1Mbps contracts. If you can't find your contract, the easiest way of telling whether you are on a fixed rate contract or not, is to check your upstream connection speed - if it's 228 kbps, then you are on a fixed rate contract.

Of course, most people are now on "up to" contracts of 2Mbps, 8Mbps or even faster. The reality is, unless you live next door to the exchange, you are not going to get the maximum theoretical speed. The further away you are from the exchange and the poorer the quality of your telephone lines, the lower your speed will be.

To check what speeds you are getting and what speeds you should be getting you need to follow a few simple steps. I've used my own connection as the example. The first thing you should do is use the BT Speedtester.

If you click on the picture above to expand it, you will notice that the downstream DSL connection speed is 1568kbps, the upstream DSL connection speed is 448kbps, the actual throughput is 382kbps and the IP profile is 500kbps. This is symptomatic of a poor connection with problems!

The upstream connection speed of 448kbps tells us this is a DSL-Max connection (up-to 8Mbps actually!). The downstream DSL connection speed of 1500kbps is the speed my router has negotiated with the DSL equipment at the exchange, but the IP profile of 500kbps has effectively capped the maximum download I can get. After a few good days with no problems, my IP profile can go up to 1250kbps, but lately we've been having more problems than usual. Remember, if the BT Speedtester returns a value of 228kbps, you are on a fixed rate product.

Your next step in testing is to go and visit the marvellous Kitz website and use the Broadband Availability Checker.
This provides a great deal of information, a little of which is shown in the picture to the right.

This shows that BT's line speed estimation for my connection is 500kbps - exactly what I am getting. Unfortunately, this measure is both useless and a great disadvantage to you, the consumer. In the first instance, it varies. In my case, it often shows my line is capable of speeds up to 1.5Mbps. On a bad day, like today, it shows a much lower speed. How it disadvantages you as a consumer is very simple. If you are having problems with BT and think about changing ISP, the new ISP is likely to use BT's speed estimation to offer you a service. What's the best they will offer me today? 500kbps, on a line that regularly gives me an IP profile of 1250kbps.

Intentionally, or otherwise, BT's line speed estimation tables stifle competition and is something OFCOM should take a very close look at indeed.

The Kitz output shows the distance between the exchange and my house is 3.44km as the crow flies, or 5.79km by road. So, the length of the telephone line between my house and the exchange probably lies between these two distances. Luckily, I happen to have a good idea of the length of the line, which is 3.361km from exchange to street cabinet and around 500 metres between the cabinet and my house.

Knowing this, I can get a downstream attenuation figure from my router - and here I get a figure of 63.5dB. Unfortunately, 63 or 63.5dB is the maximum attenuation value that most routers can register. My actual attenuation is possibly much greater than this. However, it doesn't matter for the next bit of information you need to collect. Go to another Kitz page to get an estimate of the maximum speed your line might achieve based on attenuation. Please note that this model only accepts whole numbers.

Because I have a fair idea that my overall line length is 3.9km, this result tells me is that my line is behaving like one that is much longer. Why? because the majority of my line to the exchange is aluminium, which suffers from 50% greter attenuation than copper. Sadly, aluminium was used by the GPO many years ago, to save money - often in rural areas, which partially accounts for poor broadband in rural areas.

The final stage is to check how much attenuation, and how long your line would have to be, to get the IP profile BT claim you should be getting - in my case, today, 500kbps. The Kitz checker can only take attenuation figures up to 67dB, which gives a line length of 4.85km and an IP profile of 1Mbps - so my line is behaving like one much, much longer than 4.85 km

So, by collecting this type of information, you can get a better idea of whether the speed you are getting is realistic or not. Your line attenuation is the best measure of this, but can be complicated if, like me, you are at the end of a very long line. However, if you can get an accurate line length, it is much easier to see if there is a severe line problem.

No comments:

Having had some major problems with my own broadband service, I understand how others struggle to get help from BT.

There is a lot of good information out there, but it can be hard to find. So this blog is an attempt to pull some of it together, in one place.

It's a blog that really shouldn't be needed - if only BT and possibly other ISP's in the UK, provided useful customer support.