Contention ratios on DSL

LoBo

Hi all,

I'm trying to get DSL for our company (on the crown alley exchange in temple bar) and haven't yet decided between Eircom and EsatBT. (currently Eircom is supposedly laying a new line to replace our current one into the building which apparently rats have eaten, so I have some time to check the offerings of both companies)
I specifically asked both companies what sort of contention ratio was used and both have told me that they don't - that in fact you always have the (say) 1Mb available.
Can anyone tell me more about this? I was always of the opinion that DSL was by nature shared amongst subscribers - and so you wouldn't always get your maximum bandwidth; and that contention ratios are to make sure you get a certain minimum bandwidth even if everyone's using as much as possible.

Thanks in advance

ps- unfortunately we are out of LOS for the likes of leap etc

Drazhar

Rats have eaten the line <-
Ironic, rat providing the line aswell!!!

sorry, not much help i know

flamegrill

LOL @ Drazhar

But seriosuly its quite possible that thy dont have a contention ratio for business customers. if they did id say its either 8:1 or 4:1 or in the Rats case more like 20:1, you are right about DSL being shared, so its highly unlikely that they dont have it in place.

The person you spoke too probably didnt know what you were on about.


Paul

niallsmart

That is an at best misleading answer. The DSL connection between your DSL modem and the DSL access multiplextor (DSLAM) located in the exchange is indeed a dedicated 1mbit connection. However the uplink from the DSLAM to the ISPs network is shared between all users connected to that DSLAM.

I seem to remember reading the figure 1:24 somewhere in some Eircom literature that I cannot locate now, you can assume it is somewhere within that region.

I would escalate the question with your representative - they *should* be able to give you an answer if they competent. (Yeah, I know, I know, of course they aren't - we are talking about Irish telecom companies).

Snaga

What niall said.

Eircom 24:1
Esat 20:1

With esat the contention ratio is dependant on the service, for example......

The DSLAM has a single 512k line for 20 customers on the 512k service (2 for 40, 3 for 60 etc..)and a single 1meg line for 20 customers on the 1meg service etc...(2 for 40, 3 for 60 etc..)

so someone with the 1meg service will not be sharing the same connection back to the core network as the 512k customers.

LoBo

thanks for the info - that's what I thought, will follow up with them.

Snaga where did you get your info? I'd like to point it out to them please.

Kenshin

I'm not sure if that's true...
My DSL line in Spain is just 256/128, but it always maxes out when I'm downloading from fast sites, or multiple mediocre sites, etc...
Does that mean they dont use contention ratios in Spain? I'm sure that other people in my area rape their DSL, too, but it never affected me at all...

the Guru

Excatly what Niall Said

But from a business point of view and as bad as Eircom are I would opt for there DSL and My reason is that Because the Esat DSL has no Cap and you can share the Connection the market is going to get flooded with ESAT users and there contention ratio is 20-1 saposidly and when all those little boys are D/L there p*orn it going to effect you in your business i.e **** conx but if its not business critical and Im guessing it is but at the End of the day you have to make the decision and if your looking for a router that you can pay of each month check out TRONIX you can even order from these guys

DC

The DSLAM has a single 512k line for 20 customers on the 512k service (2 for 40, 3 for 60 etc..)and a single 1meg line for 20 customers on the 1meg service etc...(2 for 40, 3 for 60 etc..)

Maybe it is a contention ratio of 20:1, but that would only work if they had maybe 6Mbits among 240 customers, for example. If it was just 20 customers sharing 512Kpbs, then noone has a chance of the full download speed.

Time will tell whether I will keep my download speeds of 64KB/s. Still, as long as it stays above 45KB/s I won't complain too much.

Urban Weigl

If you can get it, I would recommend EsatBT. Why? They have a better global network, and from reading other posts here I seem to recall that they are faster (at least in terms of latency, which seems horrible on Eircom).

Not to mention that they do not have a cap or long term contract (with Eircom you need to sign a 12 month contract). This means that if 3 months down the line you decide for any reason that you no longer need DSL, or wish to switch to another provider, you can do so. And no cap means you'll know what it will cost you each month, instead of being hit by a surprise bill.

LoBo

Originally posted by Snaga
What niall said.

Eircom 24:1
Esat 20:1

With esat the contention ratio is dependant on the service, for example......

The DSLAM has a single 512k line for 20 customers on the 512k service (2 for 40, 3 for 60 etc..)and a single 1meg line for 20 customers on the 1meg service etc...(2 for 40, 3 for 60 etc..)

so someone with the 1meg service will not be sharing the same connection back to the core network as the 512k customers.

Just to drag this up again - anyone able to tell me for certain about this? If you could point out where you got those 24:1 and 20:1 figures from?

Thanks

cgarvey

Originally posted by Urban Weigl

Not to mention that they do not have a cap or long term contract (with Eircom you need to sign a 12 month contract).

Either this is wrong or ESat BT phone staff are giving out incorrect information, and their contracts are wrong. Because I've been reading about this 3 month ESat contract and had been thinking it was great (in rented accommodation).

However, two ESat sales people both said it was 12 months (and the 2nd one checked with her supervisor. That's not definitive though, but Section 1.1 of their contract says "Minimum Period means the Minimum Period of one year commencing on the Operational Service Date" and Section 29.1 "Either party may terminate.... such notice to expire on or after the end of the Minimum Period"

So can someone point me to where the 3 months idea came from before I sign the 12 month contract?

.cg

Serbian

From reading other threads, it seems that when ESAT originally launched the product, they were asking people to sign a 3 month contract and pay 3 months in advance, but that has since changed. They want people to sign a 12 month contract now. I don't know how much they would expect you to pay in advance now.

Thinking about it though, maybe they are asking for 3 months pay in advance but you still have to sign a 12 month contract. Someone probably confused paying a 3 month advance as a 3 month contract...

zynaps

Originally posted by Urban Weigl
If you can get it, I would recommend EsatBT. Why? They have a better global network, and from reading other posts here I seem to recall that they are faster (at least in terms of latency, which seems horrible on Eircom).

Unless it's an entirely different case with dialup connections, the opposite of that has been true for me, as I use nolimits and have up to and around 100ms knocked onto my ping times when compared to ping times when I've been connected to eircom "free".

Sorry if this is irrelevant, I just assume if their dialup network is slower, presumably the same would apply to their DSL.

zynaps

Mountjoy Mugger

Originally posted by zynaps
Sorry if this is irrelevant, I just assume if their dialup network is slower, presumably the same would apply to their DSL.

Not irrelevant, but not the case based on reports from Esat DSL users on boards.ie

eth0_

BTW, the contention on 1mb DSL is not the same as on 512. on 512 it's 24:1 on eircom, and 20:1 on Esatbt. I'm pretty sure it's under 8:1 for a 1 meg line.

LoBo

etho_ - could you point to where you are getting your info from please? I have asked both EsatBT and Eircom about this and want to find out the actual details - it would help if I could point to wherever you are getting your info from.

LoBo

btw - just got confirmation from esatBT that they have a 20:1 contention ratio on all 3 of their DSL packages (512kb 1Mb 2Mb). I guess its official then :rolleyes:

This then means that if all 20 people you share bandwidth with are downloading at full blast your connection drops to the equivalent of 56k dialup for the 512Kb, ISDN single channel for the 1Mb and ISDN dual channel for the 2Mb - right? Seems a bit much to have such a high contention for an already very expensive service.

sutty

Anyone know what exchanges are next to be upgraded, I got a mial from esat a while ago saying leixlip was soon to be done (where I live) I'd consider getting DSL my-self if I knew it was going to get cheaper

eth0_

Originally posted by LoBo
etho_ - could you point to where you are getting your info from please? I have asked both EsatBT and Eircom about this and want to find out the actual details - it would help if I could point to wherever you are getting your info from.

Sorry that 8:1 thing was just a rumour I heard on the internog.