Pre-qual Line Tests

Paul007

Does anyone know the exact method Eircom use for testing phone lines for DSL?

I know lines are tested en masse once a month by computer at the exchange but what system do they use?

I was just reading an article about BT and they use Teradyne's Celerity to pre-qualify their lines. Seems to be fairly popular with Teleco's around Europe.

I wonder if Eircom use the same system?

http://www.teradyne.com/prods/btd/celerity.html

BT Interview
http://www.dslprime.com/a/BTClayTest.htm

beller b

That's the one they (eircom) just won't answer>> The only way I think we will find out is by a friend of someone on boards.ie ( Come on someone must have a buddy in eircom?) What I do know is that it is not 100% & final like they claim it to be. I had line fail only to pass when I demanded either a retest or an explanation of the criteria used . Smart also seem to be able to provide service on lines that eircom fail..

Blaster99

They're obviously not using a system where they're estimating the loop length because they can provide Smart with SNR dB ratings etc of the line, for instance.

iano

Blaster99 wrote:

They're obviously not using a system where they're estimating the loop length because they can provide Smart with SNR dB ratings etc of the line, for instance.

God knows what they use. It is not very good, whatever it is.
As I posted once before, my line is now "Unsuitable for ADSL" since I had Sky Multiroom installed.
This despite the face that I have perfectly working ADSL (from UTV) for nearly 2 years, have a loop attenuation of 9.5dB and SNR of 35dB and have not had a CRC error in over a year.
I wonder how many other perfectly good lines are marked as "Unsuitable"? The mind boggles!

iano

A quick update - My line is now passing again, although nothing has changed on my side. DSL Router reports same SNR, same attenuation and zero errors as before.

Bizarre!

beller b

Is it just Eircom that tests the lines???ie are all other on line test just repeating Eircoms results?

Blaster99

Only Eircom tests. Even Smart doesn't test.

beller b

So do Smart just ignore eircoms tests & connect you & se how it goes?????

Sparky

beller b wrote:

So do Smart just ignore eircoms tests & connect you & se how it goes?????

they'll connect ya probably for the buisness, so id say your right by saying the see how it gos thing

beller b

Thats if they can get an exchange live first !!!!! LOL!!!!

Sparky

beller b wrote:

Thats if they can get an exchange live first !!!!! LOL!!!!

Yeah too true,

Blaster99

According to Garfield, Smart uses Eircom's test data to determine if a line would be compatible with Smart's equipment.

Sparky

well i suppose since smart are new to the market, they would use eircoms data as a base for giving the service to a customer, but if the line fails, i suppose they will say well give it a go and see if it works, and if it does, alls grand.

TBH, my line has failed on many occasions and i still have a BB service up and running.

beller b

Blaster99 wrote:

According to Garfield, Smart uses Eircom's test data to determine if a line would be compatible with Smart's equipment.

According to WHO!!!! he's gone AWOL!!!! Probobly because all the exchanges that were to be live by end of May arn't.............................

bk

When I had DSL (I'm now with NTL) I use to check my line every month for a laugh. One month it would say it failed the test then next month it would say it passed. All this time my DSL was working perfectly

Eircoms line tests are a joke.

BTW I just want to remind people to check if you can get NTL before anyone else. It is much better.

TimTim

meh, I'm happy enough with my Esat 2Mb dsl line never had any major problems, although can't wait to switch over to smart

The ntl flyer came in the door a good while back and I though, if it ain't broke don't fix it.

Solair

There are a few odd things about these tests:

That site that was linked to one of the equipment providers says that it looks for PABXs and other equipment that would be indicate the line is unsuitable and that it does this based on electrical characteristics. That sounds potentially very inaccurate e.g. your sky multiroom might have shown up with the electrical characteristics of a PBX or some other device.


Also, the way telephone lines were wired in Ireland wouldn't particularly lend itself to that kind of line testing.

New installations all have an NTU (Network Termination Unit). The white master socket device to which all other extensions must be connected. This has circuitry in it that is probabaly identifiable and can be tested.

Older installations don't necessarily use a master socket arrangement at all. The phone line comes into a junction box and multiple sockets (the beige telecom eireann ones) are connected to that in a star configuration each one containing all the necessary circuitry to protect you from spikes etc.

The modern Irish system is 2-wire and pretty simple so there was never any need to do master socket arrangements where as there was in the UK for technical reasons. In the UK two wires come into your house and into the master socket. It has circuitry that takes off the AC ringing voltage and sends it down a 3rd wire. All of the other sockets are wired with 3 wires. The idea was that it stopped your phones from tinkling when you pulse dialled. Our phones deal with that internally (as do most throught the world)

I wonder if that might actually cause a line to fail for no good reason other than the test system is not getting electrical characteristics that it considers to be a POTS line?

There's also far more DIY work than there is in most European countries, including the UK where BT wouldn't even let you connect an extension unless it was plugged into the master socket with a plug. You wern't even allowed to take the cover of the master socket in theory. In other parts of Europe rules were even tighter. Telecom Eireann was always flexible about DIY work and tended to allow customers to do anything they liked inside their own homes.

I'd like to see independent validation of this testing system to see what it actually does and how accurate it really is...


I seriously don't believe that the copper wiring's THAT bad. For starters, most of it was only put in during the 1980s and was done to pretty high specs


http://www.reci.ie/eircominterface.pdf

That document actually explains how it should be done.

The Real B-man

Nice 1 Solair very intersting are you a eircom engineer?

bk

TimTim wrote:

meh, I'm happy enough with my Esat 2Mb dsl line never had any major problems, although can't wait to switch over to smart

The ntl flyer came in the door a good while back and I though, if it ain't broke don't fix it.

You kidding, you should have signed up for NTL months ago.

I changed from Netsource 2m to NTL 3m and I haven't looked back. While Netsource was also working just fine, I'm now paying far less for a far superior service and not a cent is going to Eircom

Once NTL introduce VoIP (yes I have heard of Blueface) I can completely drop all Eircom services

You would actually get a superior service from NTL then Smart for the same price:

NTL 2m/200k = €35 per month (install, equipment and first three months free) and you get basic TV free for 12 months!!!!

Smart 2m/128k = €35 (install and equipment free).

And unlike Smart, NTL isn't just smoke and mirrors, they are actually available now.

Solair

I'd just be curious to see if a failed line might pass if you simply removed all of the internal wiring and left a single NTU (be it the modern white one or the original telecom eireann beige socket) connected directly the the phoneline.

I'd say you might see cases where the new eircom line-upgrade promise might simply mean they'll come around and rip out your extension wiring, install an NTU and suggest you buy a DECT cordless phone and a few handsets instead

Pairgain systems are a totally different issue, but there seem to be a lot of normal lines failing... which seems a bit odd.

Sponge Bob

Solair wrote:

I'd just be curious to see if a failed line might pass if you simply removed all of the internal wiring and left a single NTU (be it the modern white one or the original telecom eireann beige socket) connected directly the the phoneline.

Lots fail afterwards too , search for the phrase >> internal wiring << to see how often it came up for discussion here before .

Solair

Well, to be fair, it's probabally the reason for quite a large number of the "failures" in urban areas where the line's arn't on pairgain and and there's not a lot eircom or anyone else can do if someone's opted to wire their internal phone sockets inappropriate cable other than suggest they rip all of the non approved stuff out.

We moved into a house where the phone sockets were wired with coax! i.e. the stuff you use for a tv antenna. To make matters worse they'd used arial sockets and plugs to connect the telephones too! Not exactly ideal. Others were wired with speaker cable and even 16amp elecrical cable that'd you'd normally use to wire up an extension lead!

Although, the same house had bathroom lights wired up by simply twisting the cables around eachother, wrapping with sellotape (not even electrical tape) and plastering them into the walls.

:eek:

Sponge Bob

Solair wrote:

We moved into a house where the phone sockets were wired with coax! i.e. the stuff you use for a tv antenna. To make matters worse they'd used arial sockets and plugs to connect the telephones too! Not exactly ideal. Others were wired with speaker cable and even 16amp elecrical cable that'd you'd normally use to wire up an extension lead!

Although, the same house had bathroom lights wired up by simply twisting the cables around eachother, wrapping with sellotape (not even electrical tape) and plastering them into the walls.

Sponge central is fitted with RG6 or CT100 and Cat5e only , thank God . I am considering 1000Base LX to the neighbours via a drain on the side of the road .

I personally would not buy what you just described up there Solair , save as a total restoration project maybe .

Many cack wiring jobbies I have come across are that old twin twist bell cable used as phone cable and then distributed round the house in star bus mode rather than in series .

My last house had 5 sockets in strict series . the diff between the 1st and the 5th (with nothing else plugged in) was something like 51k down to 49.6 k with the laptop.

Solair

In reality wiring them in a star shouldn't be that big of a deal and shouldn't really degrade the signal (eircom regularly did it this way themselves where wiring from socket to socket wasn't practical)

The problem is that you've often got 3 or 4 master sockets all wired directly to the line. That *MAY* cause some odd results in the DSL pre-qual test i.e. it identifies it as something other than POTS line. At the very least the star should be coming out of the secondary side of the master socket, rather than just having everything wired to the raw line on it's own radial.

That house was a total rip everything out and start from scratch job. Whole place was gutted and rebuilt pretty much, it was just funny to see some of the dodgy DIY though