Adsl And Contention.

[LTJBukem]

I am pleased to say that i will be signing up for ADSL broadband next month when i move house. This is my first time using ADSL and i'm a little confused over the matter of contention.

From what i have read, most ISP's service have a contention of 50:1. This, from what i understand, means that i would be sharing bandwisth with up to 49 other users. Now, with my new house being in a city, am i to expect significant slow down? Would it be worth my while paying extra for a contention of 20:1? For the same price as a 20:1 service, i could get a 1mb downstream instead of 512kb, would that be a better idea?

Please pass on your experiences and advice.

Cheers. :)

[Virtualbody1234]

I don't know where you got that information. To my knowledge it's broadband cable that shares bandwidth with others, not ADSL.

Do you have a link to that service provider?

[ilw]

I've seen contention ratios quoted for ADSL, and 50 to 1 is standard for home broadband in the UK. If the choice is between 1Mb at 50 : 1 or 512kb at 20:1 , I'd definitely go for 1Mb. Chances are you'll never really have a dramatic slow down and you'll usually be blissfully unaware that your connection isn't at its max. The lower contention ratio does mean your connection speed is more reliably near its rated speed, but for file sharing its more important that you can download and upload more and with double the bandwidth the occasional decreases will be more than offset by the periods where the connection is good.

[Benno]

Originally posted by Virtualbody1234@15 November 2003 - 18:32
I don't know where you got that information. To my knowledge it's broadband cable that shares bandwidth with others, not ADSL.

Do you have a link to that service provider?
Yeah with ADSL you have your bandwidth reserved for you, cable shares it with others.

[Majin]

jup you`ve got it extra, the bandwith

[ilw]

I'm pretty sure all internet service providers use contention ratios, ie they all sell the same piece of bandwidth many times over.
I'm really really not sure about this but i think with cable the contention ratios are much more noticeable because the groups sharing bandwidth are much smaller for example in ADSL the contention ratio is nationwide (or across a wide area) so if they have x thousand MBs of bandwidth they sell 50x thousand MBs, but the contention for any bit of that bandwidth is spread across the entire network so the overall fluctuation of demand is smooth and mostly levels itself out, whereas with cable I think its more localised ie in some places the sharing of bandwidth might be limited to a few blocks so its a lot more noticeable.
Btw thats complete and utter speculation, :P I'm almost certainly horribly wrong, but i'm really bored and i can't be arsed to google it.

[LTJBukem]

Thanks for taking the time to answer.

Here are the two isp's i'm considering.

http://www.eclipse.net.uk/index.cfm?id=bbresidentialservices

http://www.plus.net/info2/residential/res_...elfinstall.html (http://www.plus.net/info2/residential/res_broadband_adslhome_selfinstall.html)

I've had both recommended to me, and from what the reviews i've read they provide the best services in the UK. I'd never heard of contention until i strted researching the subject.

This in particular i don't like the sound of:-

Contention rates of up to 50:1 are expected on the service (you may share the available bandwidth with up to 49 users), although it is generally agreed that rarely would all be transferring data at full speed simultaneously.


Let me know what you think.

:)

[Virtualbody1234]

Ok then, I guess i'm lucky. I have 1.2 meg dedicated unlimited ADSL service. I had not heard of sharing on ADSL untill now. :blink:

[LTJBukem]

FAQ's
What is Broadband?

Broadband is a blanket term for a range of technologies that allow access to the internet at much higher speeds than normal dial-up connections. While current 'narrowband' systems can typically carry information at a rate of 56kbps (kilobits per second), broadband often allows rates of 512kbps and can offer speeds many times faster.

The main types of broadband technology include ADSL (Asymmetric Digital Subscriber Line) - a technology that allows normal telephone lines to carry more data - and cable modems, which allow you to connect to a higher-speed cable network in your area. Other alternatives include satellite technology and high-speed wireless networks.

One of the most important thngs to remember about an ADSL broadband service, is that there is a contention of the overall available bandwidth amongst other local telephone exchange ADSL subscribers. This means that if an ADSL service is locally popular, you must be prepared to accept connection speeds that are possibly less than those advertised by the service provider. Typically, for a 512K "downstream" (ie. data coming from the Internet) service, there will be a choice of whether to subscribe to a 20:1 or 50:1 contention ratio, which naturally has service cost implications. Upstream (ie. data going out from your network) transfer rates could also be affected (usually there is a maximum upstream bandwidth of 256K), depending upon how many subscribers are using the service, and at what time of day it is.


You are very lucky. :blink:

:)

[Lamsey]

I have 50:1 contention on the Eclipse.net ADSL Connect 500 Lite service, and have never noticed any slowdown at all in the 4 or five months that I've been with them.

[lynx]

The line rate (512kb/s, 1mb/s etc) is the rate between your pc and the local head end. You don't share that. The contention ratio is the number sharing the link between the local head end and your isp's hub, and they don't tell you what speed that runs at.

The contention rate on my connection is 50:1, but I have never noticed any slowdown, so for the same money you would be better off getting 1mb at 50:1 rather than 512kb at 20:1.

[LTJBukem]

Thanks to you both for replying. I'll probably go for the 512 at 50:1 on Eclipse, as has Lamsey.

Lamsey, why is this package called Connect 500 Lite? Does this only refer to the contention and nothing else? I've looked on the website, and there don't seem to be any difference otherwise, but am i missing something? I'm still not really clear on why there would be two packages, differing only by contention, if contention isn't an issue for the end user.

Spot the difference:-


Originally posted by ADSL Connect 500+ £32 a month--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (ADSL Connect 500 &#064; £32 a month)</td></tr><tr><td id='QUOTE'>
512Kbps download
256Kbps upload
20:1 maximum contention

Includes email and web[/b]

<!--QuoteBegin-ADSL Connect 500 Lite@ £20.38 a month

512Kbps download
256Kbps upload
50:1 maximum contention

Includes email and web[/quote]



:blink: