Do eircom provide ADSL2 connections?

yuloni

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bk

Not true, ADSL2+ offers better speeds over longer lines. ADSL2+ is an extension of ADSL2 and can do everything it can do and more.

But to answer your question, no they don't offer ADSL2, just RE-ADSL, ADSL2+ and VDSL

yuloni

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ED E

I assume that graph is from a full DSLAM, there could be increased crosstalk from 2+ but in order for the benefit you think you're looking at you would need the entire exchange to switch over.

Real world though the lines are probably not in perfect condition and theres hundreds of other sources of RFI in between you and the exchange, so the difference is very negligible.

yuloni

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ED E

The new VDSL stuff was Alcatel for the trial and Huawei for production. The phone gear in old exchanges is Alcatel + Erricson I think, SpaceTime would know I suspect. Dont know what the ADSL line cards are, probably a mix as they've been slowly installing them for years.

The old 2247 Netopia/Motorola had a great little ADSL chipset in it and is one of the better options on a long line. Keeping that in operation is a good idea, but I'd bridge it to a real router/wireless AP nowadays.

You can squeeze a little extra performance out of longer lines but really you're talking a few hundred k, its really not going to keep up long term either way. Unless you're in an area planned for VDSL I'd investigate fixed wireless.

yuloni

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ED E

Bad modem code can certainly cause issues alright, the Fritzboxes had problems where they butchered line rates when vectoring was turned on. Thats a little more complex than traditional ADSL, but same idea.

If they start doing EVDSL you may even see a small further drop off, they're limiting it to lower frequencies but you're still going to have a load of parallel lines signalling at far higher rates than they were.

You sure its 8km? DSL is basically dead at that range, you get very little after 5500M's usually.

srsly78

If you want to improve stability then you have to drop the sync speed. Check the error statistics on router. An extra 500k speed is no good if it drops packets frequently.

lockup35

Just a quick question on ADSL2+. Are all Eircom exchanges running ADSL2+ actually NGB exchanges?

MBSnr

yuloni wrote: »

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Seems the D1000 can't tolerate longer cable runs in your instance. I'm on a much shorter run and I changed from the Netopia 2247 to the D1000 (there's later firmware available - here) as it performs better - faster wireless for my repeater and devices and a USB port on the back.

yuloni

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ED E

yuloni wrote: »

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Strange. Very strange. Theres gotta be an RSU or something in between, or its actually fed from another exchange. That or maybe if all the other lines are PSTN only then you would have no crosstalk on DSL tones. But still, its miracle sync kind of territory.

Eircom DSLAMs cant read above 63.5 but if they run a POTS test they can give a pretty accurate idea of loop length from the AXE(telephone card).

The modem and DSLAM do a sync broker call when they link up, negotiating what they can manage. They'll test rates up as high the profile which is really like a "max allowed" rate, not a fixed provisioning, and sync at the best functioning rate in that instant. So if you sync at 1500k when the line is doing alright and then theres a burst of noise the rate of errors will sky rocket and the DSLAM will say f'ck this and drop the sync. The process starts again but now the line is faulting and the best rate is 400k say, so it syncs there. It wont re-sync back up higher again until something causes it to fail again or you reboot it. So in this way it can get "stuck" low after a resync.

Intermittent crackling on the voice band could well be moisture ingression. Get them to send the techs out but on that long a loop you might have a hard time getting them to find all the bad bits.

yuloni

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ED E

Map is pretty conclusive alright. Very lucky for you.

Wonder if you might be on a main cable all by yourself, if they expanded from an original say 25 with another 25 pair then you could have a very "quiet" bundle. But thats total speculation.

The billion sounds like a fun project anyways, would be interested to see rate/snr graphs if it can produce them.

yuloni

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yuloni

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ED E

There are exchanges that have upgraded wireless backhaul that have ADSL2+ to 24Mb but are not NGN. Wouldnt be many though.

lucernarian

Just to clarify some of the things quoted in this thread, any dslam capable of G.DMT.bisplus is inherently capable of G.DMT. bis as the only difference is busplus (aka ADSL2+) has its downstream bandwidth extended to 2.2 MHz or some number like that. I am connected to BT's equipment but as I am connected at 3072kbps on a line physically incapable of using tones over 1.1 MHz, ADSL2+ is not possible to achieve. The line is 6.5km long. The modem reports I am using G.DMT.bis. eircom's prequal precludes such a scenario from happening but there are eircom techs who know exactly what those exchanges are capable of.

Although I get a stable 3 Mbps, if all my neighbours were allowed to do so then that would be reduced. Still, I'm surprised at the lack of variance in SNR when i force ADSL or ADSL2. It stays at around 7db (bearing in mind its hard to know if its reporting true signal margin or just snr and the different standards have different minimum required snr values).

Take it from another miracle line user who has done lots just to enable 3 mbps on the line, the modulation type may not make much difference. If you want I can show screenshots.

Also with each resync the exact stats and snr can vary as at any given point on the line, there can be simply less electrical "noise" generators and unusually quiet spells vs unusually noisy spells with lots of background EMI. Basically, the longer the line the more variable the SNR.

Mr. G

MBSnr wrote: »

Seems the D1000 can't tolerate longer cable runs in your instance. I'm on a much shorter run and I changed from the Netopia 2247 to the D1000 (there's later firmware available - here) as it performs better - faster wireless for my repeater and devices and a USB port on the back.

The Netopia 2247 was great, I agree. The only problem in my experience was that if you were very near the exchange and on the 24Mbps profile, the line would fluctuate between 20Mbps and 23Mbps. Only when I tried the Billion router was I able to get the full 24Mbps.

Just my experience, but wouldn't be relevant to the op I suspect.

yuloni

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lucernarian

Basically yes. Any adsl2 dslam would be automatically capable of ADSL. I've tried this with BT and Eircom DSLAMs. I remember people writing that Smart's ones also allowed it.

I'm pretty sure though that given how eircom have both ADSL and adsl2 line cards, prequal tests will decide which one a line is plugged into.

yuloni

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lucernarian

yuloni wrote: »

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Can you explain how you will be maxing out this line? Does it pass prequal for ADSL2+

I don't understand the reasoning behind ADSL2 and distance limitation purely because ADSL2 should automatically work on any line that can handle ADSL1 and possibly a little better. Initially I'd say they were trying to conserve ports in their new line cards but now I'm wondering why they don't just allow ADSL2 connections by default.

yuloni

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ED E

lucernarian wrote: »

Can you explain how you will be maxing out this line? Does it pass prequal for ADSL2+

I don't understand the reasoning behind ADSL2 and distance limitation purely because ADSL2 should automatically work on any line that can handle ADSL1 and possibly a little better. Initially I'd say they were trying to conserve ports in their new line cards but now I'm wondering why they don't just allow ADSL2 connections by default.

I'd wadger it comes down to the prequals and they werent bothering/facilitating port orders for legacey 7Mb packages to 8/24Mb packages for lines that prequal less than 8Mb.