Contention Question

Niall1234

Just say that the Contention ratio on a certain package is 48:1.

Right, say you signed up to a smallish operator like Smart.

Now say that you are the only Smart customer for that local telephone exchange.

Does that mean you are not actually sharing the bandwidth with anyone else or would you be sharing with say other Eircom users ?

dub45

You picked a bad example as Smart don't share with Eircom and promise a contention free product.

If you are thinking of Eircom and its resellers the answer afaik is that you cannot avoid contention in the way you are thinking of.

Cal

If you are the only connection with that ISP at the exchange and your ISP is using their own DSLAM at the exchange then yes it is all yours (throttled to the speed of your package). If the DSLAM is being shared then you will still be subject to contention.

I would have thought the ISP's would own their own DSLAMs at the exchange.

Cal.

Liam Byrne

As Dub said, it doesn't matter how many subscribers are connected to their equipment at an exchange; their network is contention-free.

All eircom resellers have to put up with eircom's crap contention ratio.

In theory, if you were the only one at that exchange, you could temporarily enjoy contention-free broadband for a while.

kaizersoze

Plus if you were the only BB customer connected to the exchange, the sales team would get an unmercifull kick in the hole.:D

I've been on 48:1 and 24:1 and in all thats said about contention, I'v never have been affected by it.

DemonOfTheFall

I'm slightly affected by the Contention on my NTL BB, pings are a bit higher at peak times and download speeds are in the 6xx KB/s range instead of the 7xx KB/s range.

With BT my pings went up by about 10 at peak times but other than that didn't notice at all.

Magnet are being a bit underhanded with the contention thing really, most people will never be affected by it, as long as they're with wired ISPs.

Liam Byrne

most people will never be affected by it

Wait until your entire neighbourhood is watching movies or TV via the net!

Or is there something I'm missing ?

dub45

There was a major contention issue a couple of years ago which affected both BT and UTV customers badly (it also exposed a 'connection' between UTV and BT which most us had not realised before). Basiclly there was not enough bandwidth ordered and contention kicked in badly for both sets of customers.

Anyways if I recall correctly some of the teccy guys pointed out that there was lots of areas where contention can kick in apart from the sort of nomimal 24/48 thing so maybe someone could tell us a bit more about that aspect of things.

vimak

I don't really understand all the fuss with contention ratios in Ireland. I used to have broadband in Finland since 1999/2000 (can't really remember) and never heard or experienced problems with contention ratio. (and I've lived in many different places and talked to a lots of people). So... what's wrong with Irish broadbands? (Before I came here, I had 12M ADSL without any problems, no matter what the time)

Evil Al

Liam Byrne wrote:

As Dub said, it doesn't matter how many subscribers are connected to their equipment at an exchange; their network is contention-free.

That of course is a complete fabrication that Smart and Magnet have been putting about. I have yet to see *any* network that is "contention-free" (at the moment, Magnet's DSL network is what I would describe as "down", so the question is moot).

What Smart and Magnet actually mean is, the small portion of the network between your modem and the website you are trying to reach that falls between the telephone exchange and their datacentre is not subject to eircom's normal 48:1 or 24:1 *maximum* contention. This may or may not be a consideration at all, depending on where you live, what you use the net for, and what time of the day you usually are online. Magnet and Smart make no promises at all about contention within their IP backbone; contention on their links to INEX; the uptime of their DSLAM; or contention on their international transit links, all of which may (or may not) have a larger impact on your internet access experience than the mythical "contentio ratio" on bitstream, which at least eircom are very up front about.

Also, note that the "no contention" b.s. onlyapplies to Smart and Magnet customers on unbundled line (i.e. you change your phon number etc) and not to the huge majority of their customers who are actually on bitsrteam.

Basically, people can debate this for hours, but *forget about* the advertised ratios. Try a few providers (i.e. at friend's houses if you can) and find one that gives you decent performance for what you need.

/rant

Alex

Foxwood

Evil Al wrote:

Magnet and Smart make no promises at all about contention within their IP backbone; contention on their links to INEX; the uptime of their DSLAM; or contention on their international transit links,

Maybe you should actually read what Magnet state clearly on their website before sounding off about them:

b. With respect to congestion beyond the point of connection, our network contains many gigabit links which are dimensioned, monitored and increased from time to time to carry without congestion the maximum load placed on our network by our active customers.

Also, note that the "no contention" b.s. onlyapplies to Smart and Magnet customers on unbundled line (i.e. you change your phon number etc) and not to the huge majority of their customers who are actually on bitsrteam.

Smart doesn't have a single customer on Bitstream - the "vast majority" (actually 100%) of their broadband users are on unbundled lines.

Liam Byrne

OK, so the "small portion" between the house/business and the exchange may or may not be the only section in question (you say yes, Foxwood says no, the entire network is optimised). I don't know enough to confirm either of you.

But even still, that's like having a slip-road onto a motorway....if the sliproad is congested at peak times, whether the motorway is the M50 or the N7, that congestion will still affect your access, and you try getting out quickly if there are 47 cars ahead of you.

The one bit that Foxwood did post that I CAN back up is that the only option available for me to get broadband was to change number (thanks eircom :rolleyes: ) via LLU with Smart, so bitstream doesn't come into the equation at all.

Foxwood

Liam Byrne wrote:

you say yes, Foxwood says no

I didn't say no, I said that Magnet lay out their policy with regard to contention in plain English, one click from their Home Page. So I wouldn't put too much weight on the opinion of some anonymous pundit on boards.

Evil Al

Foxwood wrote:

Maybe you should actually read what Magnet state clearly on their website before sounding off about them:

I can't for the life of me find that quote on their site to see its context, but I believe you that it's there.

I know quite a bit about how Magnet operate and if you believe there's no contention on their internal & transit network I'd like to interest you in a rather large bridge.

Smart doesn't have a single customer on Bitstream - the "vast majority" (actually 100%) of their broadband users are on unbundled lines.

No but Magent/Netsource do... and in aggregate the two of them have more bitstream customers than LLU customers. The true number of Smart LLU customers is a somewhat disputed figure within the industry, of course.

Thanks,

Aex

Evil Al

Liam Byrne wrote:

But even still, that's like having a slip-road onto a motorway....if the sliproad is congested at peak times, whether the motorway is the M50 or the N7, that congestion will still affect your access, and you try getting out quickly if there are 47 cars ahead of you.

Oh I agree completely -- contention is bad, m'kay. But I've seen this sort of crap before... companies occasionally try and pick a particular poorly-understood technical attribute and hang an advertising campaign on it. Foxwood has clearly read their policies and taken them at face value -- which I am unable to do, having seen how things work from the other side of the fence. There are many, many reasons why their explanation could be taken as misleading, depending on what you mean by "contention" (a planning ratio? A 2-week lookback of 95th percentile traffic? A peak traffic figure? With framing overheads removed or not?)

While it's admirable to see people trying to reduce contention, you should really take their claims with a metric ton of salt -- and certainly not at face value like some other anonymous pundits do :-)

Thanks,

Alex

SeaSide

Evil Al wrote:

Magnet and Smart make no promises at all about contention within their IP backbone; contention on their links to INEX; the uptime of their DSLAM; or contention on their international transit links, all of which may (or may not) have a larger impact on your internet access experience than the mythical "contentio ratio" on bitstream, which at least eircom are very up front about.

hmmm

do we not refer to this as congestion???

the mindset everywhere except eircom has moved from managing the ratios (8 subscribers to a modem, 4 modems per backhaul link etc or 48 DSL subscribers to an ATM handoff) to managing congestion or ensuring that there is no congestion in the network.

most isps into INEX have only one connection so by your definition there would be high contention but there is in reality no congestion so there are no quality issues.

Foxwood

Evil Al wrote:

I can't for the life of me find that quote on their site to see its context

On www.magnet.ie, the last ink on the navigation bar across the top is call Q&A. The first section of their Q&A is about contention.