A question about adsl and lines.

segadreamcast

Hmmmmmmmmm...was talking to the Eircom adsl folks again on Monday, asked them about my phone line again.

For the second time in four phone calls, they said I was on the Santry exchange (the other two times they had said Finglas, weird, non?)

Anyway, the guy said that the Santry exchange hadn't been updated for adsl trialling yet, and wouldn't be until december-january...then some mumbling went on in the background and he came back saying it infact had been updated, he just hadn't been informed. (Nobody else had told me this...were they foolin' about?)

Then (here's where my real question kicks in) they tested the line, and I had a glimmer of hope in my life...But that was soon to be crushed when they said the line wasn't able...

But how? My average connection speed is 46666bps on a 56k, going up to 53100bps and with the minimum I've ever connected at being 45333bps, would that not indicate a good line? I'm rather confused, if someone cares to clarify for me.

Thanks alot,
~Noel

chernobyl

Some peeps seem to be under the illusion that an £ircom line test is for real, they give DSL to whoever they want and its just easier to say you rline did not pass the test then make an excuse as to why they wont trial you because you can argue that.
surely there are always £ircom eingineers at that exchange, so stalk it out and ask them to do a local test for you.

segadreamcast

Hehehe...shows how insane I am seeing how I'm realistically considering doing that...or perhaps I'll just keep trying and see if they'll randomly accept my pleas...

Who knows...might work?
~Noel

pete

i just used http://interactive2.iol.ie/maps/iolroute.asp to check and i live 4.7km from the exchange

hmm

i get 46000bps connections

why did my line fail then?

Supercell

Pete, on my extension cable i get 50.6 or 52.0k in win2k, plugged directly in i get 53.2k every time. I failed..

TBH (and hopefully the knowledgable here will confirm) , dial up connect speed is no indication of ability to receive a DSL service. Even though i dearly wish it was so.

I know how you felt when you failed the line test, i was utterly crushed, it was my best hope..

For the moment i will have to put up with pay through the nose dialup and Europeonline( v cheap satellite service for queing and eventually beaming down files), for my downloads. Though there is a community of filesharers on that service which makes it pretty reasonable.

pete

i guess i'd just like to know what tests (if any!) they are actually doing - and what are the likely causes of failure

NeilF

I don't know what kind of test Eircom carry out, or even if they do test the line, as chernobyl points out However, the reason lines with high connect speeds fail could have something to do with the frequencies involved.

A normal phone line operates over a range/band of frequencies, those used for normal speech. The line is capable of supporting transmission on other frequencies, but they remain unused.

ADSL uses this fact to establish a data connection over a higher range of frequencies. Voice calls can still get through on the lower band. Hence the splitter for the phone on some ADSL setups, it is essentially a band pass filter that allows some frequencies through and keeps the rest out.

So while you may have a very good connection to your exchange on the frequencies used to transmit voice (and modem talk), the frequencies for ADSL don't get through as well, possibly due to interference from something along the way.

ando

yeah, that girl i was onto last thursday, rosmery, she tested the line herself while i was on the phone to her... it took aprox 1 minute to test the line, but when i ordered my new line (last friday) I was told that they cannot test the new line (after installation) from their desks, only the engineer's can test them....

pete

So while you may have a very good connection to your exchange on the frequencies used to transmit voice (and modem talk), the frequencies for ADSL don't get through as well, possibly due to interference from something along the way.

yeah it's the "why not?" for this that i'm curious about...

Rojam

Had a similar scenario myself earlier today. The lady handling my call performed a software test that "ping"ed my phoneline and it failed. Interestingly, when I got home this evening my Eircom Phonewatch console was flashing orange and spoke (yes, it speaks) similar words to those I got in response from the ADSL lady - "". Master control trouble, phone trouble at 12:35 pm, now ok". She listed many reasons why the ping can fail - Phonewatch equipment being well up there, repeaters on the line, exposed cabling near flourescent tubes, botched (unshielded) DIY extensions, blah-di-blah.

So, next week I'll have my modem disconnected as well as the 2 phones and I'll remotely disable the alarm for a bit and call them back. Hell, I really need something better than the 41.4kbps I'm currently connected at. Working during the day here I'm conscious of every second I'm online (and, of course, not able to receive calls when online) and that's really not the way forward, now is it ?

Who's my TD ? That Upton wan....she wouldn't know how to spell "broadband" let alone know what it's about !

Hell, this is all wrong - wrong wrong wrong.

m1ke

that iol map site is pretty kewl. It says i'm 400 metres from the eircom cabra exchange (I can almost see the ugly building from my window here).

Anyone know if Cabra is upgraded for dsl ? I know down the road in Phibsboro and all Capel St/Market area is.

I've still got a suspicious feeling that even though I have a perfect copper line and am 400 metres from the exchange as the crow flies... knowing eircom i'd fail a line test.

Red Moose

Originally posted by pete
i just used http://interactive2.iol.ie/maps/iolroute.asp to check and i live 4.7km from the exchange

I think that's exactly the problem. AFAIK you need to be within 3km at most for ADSL to work. I think BT were using something like RDSL to extend the range to around 5km sometime over the summer, but anyway, I am almost definite that you are too far from the exchange.

It could very well be to do with frequency degradation over longer distances or something, I'd don't know much about the different types of DSL.

NeilF

Originally posted by pete
i live 4.7km from the exchange

Is that not a bit far away for ADSL? I thought the maximum distance was more like 3.5km.

NeilF

Originally posted by Red Moose
I think BT were using something like RDSL to extend the range to around 5km

2010: Eircom announce broadband available to those 5km from exchanges.

I can't wait :mad:

MS

Think about it! If EircoN had installed proper lines n the first place there would be no need for hmmm hmm 'Tests' EircoN are constantly checking lines that people say there is a fault on but! NO! there is NO! fault when they check them they say the line/s are Perfect! But u are dealing with EircoN here ..so what is their meaning of Perfect ? Perfect u can hear someone on the other end even through all the noise/2 FM/Electric fence noise etc. or perfect for data as well ? Eircon have totally perfected how to fobb people off and we fall for it every time . The trouth is ADSL will work anywhere in Ireland. But Eircon will have to make a few adjustments and update a few lines. They just wont do it!


MS

pete

Originally posted by Red Moose


I think that's exactly the problem. AFAIK you need to be within 3km at most for ADSL to work. I think BT were using something like RDSL to extend the range to around 5km sometime over the summer, but anyway, I am almost definite that you are too far from the exchange.

Bugger. I thought it was 3 - 3.5 miles.

Oh well.

Son of Blam

Just because you've looked at a map on IOL and your house is 4.5km from an exchange (or whatever distance) that doesn't mean the distance from your house to the exchange through a phone line is 4.5km.

Phone lines don't go in exact straight lines to the exchange, just like roads and pipes don't.

So in reality the distance of the "phone cable" is quite a bit longer than the distance from you to an exchange on a map, you silly kids.

Also, people over 5km from an exchange probably won't be able to connect to it using DSL due to the distance sensitive nature of the technology. The reason it's distance sensitive is because copper isn't the best conductor in the world and a digital signal on it will degrade pretty quick.

There's a good chart here that shows the average distance of ADSL connections for a few ISPs in the states: http://dslguy.com/dslpage9.htm. As you can see the average ADSL distance is around 17500ft. (17500ft = 5250 metres = 5.2km). This isn't any ISPs fault, this is because people currently aren't using superconductors for phone lines.

Also, just because you have a great analogue connection to an exchange doesn't mean you'll have a great DSL connection. I'm sure most of you know how a normal analogue phone signal only uses a small bit of the available "bandwidth" (dunno if that's the right word really) on your copper line. Analogue signals reside between 0-4000 Hz frequency ranges.

ADSL uses a much greater frequency range, up to 2.2 MHz (ie 2200000 Hz). If there's line noise in this higher frequency range then your DSL line check could fail.

Obviously there's no real way of us telling whether this is the case or not, it's just a suggestion as to why somebody on a good analogue connection might fail the ADSL line test. There are probably a million other theories you crazy folk could think up. But you should do a few searches on the net about ADSL before saying stuff like "They didn't even check my line, they're just a big bunch of stupid morons". Knowledge = power, and stuff.

-Son of Blam

spongebob

Nothing like a bit of practical science to cheer the country up so there isn't

Now!

About the matter of failing a line test because of the presence of Phonewatch equipment!!!!!!!!!

This means you could sue Phonewatch for installing faulty equipment, whoops , that means you are suing €ircon

funny how the arse and the elbow are part of the same body

M

Fergus

I'd say the impedance/capacity issue over a low line must be a bit of a problem too for high frequencies. I'm amazed DSL works at all.

In any case, there's a limit (6km or so?) on how far an ordinary POTS line can run for, after which some sort of repeater or different mode is going to be required for the line, and the intoduction of such devices would mean bye bye DSL anyway.

pete

Originally posted by Son of Blam
Just because you've looked at a map on IOL and your house is 4.5km from an exchange (or whatever distance) that doesn't mean the distance from your house to the exchange through a phone line is 4.5km.

Phone lines don't go in exact straight lines to the exchange, just like roads and pipes don't.

So in reality the distance of the "phone cable" is quite a bit longer than the distance from you to an exchange on a map, you silly kids.

Yes very good. Why didn't I think of that?

Oh, wait - I did.

First of all, at 30 years of age I don't appreciate being referred to as a "silly kid" - plus, it does nothing to enhance the quality of debate here to have people posting with attitudes like that.

Secondly, if had you bothered to engage your brain before your mouth you'd see that the page in question uses ordnance survey maps and calculates the actual travel distance between two locations (i.e. the actual driving distance along roads), and not the length of a perfectly straight line between them.

In my case, this results in a considerably longer distance than a simple straight line - but for telephone line distance guessing, this probably would also hold true.


edit: oooh you can tell i was having a bad day, can't you?

JamworkS

My average connection speed is 46666bps on a 56k, going up to 53100bps and with the minimum I've ever connected at being 45333bps

They line test are never done on the exchanges. They're always done on site, at your house.

What they usually do at the exchanges is that everything works fine and that there's nothing left to connect and that there's nothing in your line to stop the signal to reach your home socket and their DSLAM's at the exchange.

When the technician comes to the house he has to do a line test to see if your line sends and receives and to see if the noise is not big enough, if it is, either orther another line or ask them to check for noise.

At least that is what they use to do in Spain.

If they tell you something else is because they don't bother their arses.

Good Luck.

JamworkS

Boston

Originally posted by ando
yeah, that girl i was onto last thursday, rosmery, she tested the line herself while i was on the phone to her... it took aprox 1 minute to test the line, but when i ordered my new line (last friday) I was told that they cannot test the new line (after installation) from their desks, only the engineer's can test them....

thats because its not in their database, and will be a few months to get in