Written by The old adage the “you get what you pay for” is mostly true. It means you don’t get anything for free, and where you scrimp on the cost you’ll tend to get cheap crap in return.
This is certainly true in the broadband market: if you see a high headline rate for peanuts (think adverts for ‘unlimited’ 24MBps broadband at just £5/mth), then the chances are pretty high that you’ll be throttled to hell and cut off after you’ve managed to download a couple of gigabytes. Similarly if you pay more for a more honest ISP – ‘honest’ in that they don’t massively oversell their backbone network – then you’ll typically see much more reliable (and faster) results.
Now, regardless of all that, we all get screwed by the fact that the performance of xDSL technologies degrades over distance: that 24MBps might be almost true if you sleep under a desk in the exchange; it certainly isn’t true if (like me) you live a good few kilometers away. This problem is the catalyst for no end of inventive measures taken by users, from foil wrapping cables to eliminate noise, to establishing private microwave links to friends with faster connections. Me? I stick with BE who at least allow me to control the all-too-critical SNR ratio myself for a fairly reasonable price.
The SNR ratio determines the balance between all-out-hell-for-leather speed and make-it-actually-usable reliability. At one end of the spectrum you’ll have a line that synchronises at a high speed but is so noisy that packets get garbled along the way; the result is a slower real-world speed because all those garbled packets need to be retransmitted (probably repeatedly) until they come through in one piece. At the other end, you have a line configured for reliability, where potential speed is sacrificed to esnure all packets come through in one attempt. Obviously, the balance lies in the middle: there is always a sweet spot where the optimum SNR lies, and it’s always some way below the ISP’s determined setting (they want to avoid you phoning in and costing them money of course).
Unlike most ISPs, my BE line lets me set that figure. Their fastest setting gave a 20% speed boost over my previous ISP with no (perceptible) reliability issues. Great! I’ve now long believed that this is about the maximum speed my 6km-long line can support.
But, it turns out that, just rarely, you get more than what you pay for. In my case, I have a Billion 7800n router that is pretty awesome. It’s awesome before you know about the hidden /snr.html page. After that you discover it’s friggin’ marvelous! – it’s simply the best router you can buy for xDSL internet access (IMHO) … Why? Because it allows me to set my SNR below even BE’s lower limit, and somehow manages to still pull it off with no (perceptible) reliability issues.
The end result? Another 25% speed increase for free, gratis, nada.
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