Broadband speeds; do they really vary?

Chrisbang

I was just wondering, could anyone explain how ADSL broadband speeds vary?

Is choice of broadband really all about balancing customer service with cost?

Providers generally claim that speed will be the best available to the address, and many sources claim that there should be no large difference between providers.

On the other hand, people anecdotally indicate that some providers are faster than others, and I have been quoted very different guaranteed speeds from different providers.

If somebody could clarify I'd be grateful.

(Fibre optic is not yet available through my local exchange but I could use cable.)

matelodave

It depends how good your line is and the loading on the equipment and size of the connections to the exchange.

Depending on who you go with depends whether they are sharing their bandwidth or even exchange equipment. The number of people on line at the same time also has an effect. Some of the LLU providers will pay for a bigger pipe than others and may have more spare capacity than others

Think of exchanges as motorway junctions and connections between exchanges as motorways. Motorways and junctions get congested when there's a lot of traffic about. A toll road that bypasses the motorway can make the traffic a lot faster, some LLUs buy their own bypass whereas others just share the same as everyone else.
However the bit between your house and the motorway junction is similar to the cabling between your house and the exchange. The further it is and the worse the roads (or cabling) are then the slower you'll travel especially if there are lots of others using it at peak times, so even if the motorway is empty you aren't going to get to it any faster.

kwikbreaks

While ISP backhaul from the exchange to their datacentre can become congested that seems to happen less often these days - possibly because those costs have reduced or possibly because those ISPs who didn't provide enough capacity lost customers or maybe something else entirely. Whatever the reason there is a lot less to choose between ISPs on that score now than was the case in the past.

The real decider on what speed you will achieve is the length of your line to the exchange. Poor quality joints or the use of aluminium instead of copper can make things worse. The other factor is whether or not your provider can offer ADSL2+ or only ADSL as the former is potentially more than twice as fast. for short lines although that advantage drops off as the length increases. There are oodles of pages explaining this on the web and http://freeola.com/adsl2-21cn-rollout/ was one which I found with a graphic showing typical speeds/distance

Regardless of any estimate unless one provider is offering ADSL2+ (sold as upto 16Mbps and over) and the other only ADSL (sold as upto 8Mbps) you won't see much difference between them for normal downloading although different ISPs have different policies on how they will handle P2P and newsgroup downloads.

If you can get cable then that will be faster than any non-fibre service and probably any FTTC type fibre service too - certainly so if you choose faster than the basic cable. With fibre you get the advertised speed. There are (relatively small) speed penalties if you exceed published download volumes - http://my.virginmedia.com/traffic-management/traffic-management-policy-thresholds.html Some cable areas can suffer high congestion which can last for months before being fixed but there is a 28 or 30 day satisfaction guarantee.