Eircom fibre for direct to exchange news?

PFFFFFFFFFT

ED E wrote: »

Yep, 60 or 70Mb to start with, more later with vectoring most likely.

Nice!Do you have an idea of when they're gonna finish rolling out eFibre for Exchange Only lines?

ED E

So,

This has come up a couple times and I wanted to have a look. Why is eircoms VDSL2 running up to 2KM at best, not 3KM and thus a lot lower than ADSL2+ which can function at 6KM(slowly).

Well, first thing is profiles:



Eircom/Huawei have decided that the minimum profile is 7Mb_1Mb whereas ADSL products go as low as 128Kb_64Kb. That means ADSL will prequalify on a line that will barely barely get the tone at the far end. But thats only a small factor, even if they allowed a 1_0.5Mb profile we'd only get an extra few hundred meters based on current charts.

BB Forum.org have published a nice summary (see sources) of current xDSL technologies. This is an interesting table:



And more so, this graph:



Note:
30Mhz: Over 200Mb at 0M, ending at 3KM
12Mhz: Circa 100Mb at 0M, ending at 1.5KM

Seems we fit right smack in the middle of the two doesnt it? Eircom are using 17A (as some modems will tell you):



Compared to wiki:



So eircom using the 17A profile is the range limit. Thats the standard theyve chosen. People have mentioned that the VDSL2 cards could reach further, yes, but not without a big change in thinking from eircom, and the decision was probably made for a good reason.

Then theres eVDSL as eircom call it, or exchange launched VDSL. The solution for "direct fed" lines. How does that match up?

Currently the CLFMP from eircom and COMREG limits as follows:



Its safe to assume though that this has been ratified upwards to match cabinets, or at least to 12Mhz. I know a trialist on 40Mb and it doesnt seem likely they'd get that with only 2Mhz to go on (am I correct here JCA/Hackery/Spacetime?). The maps include eVDSL for a while so somethings moved along anyways but hasnt been published yet. They may or may not go the full way to 17Mhz, maybe more like 12Mhz, or go all out crazy and use 30Mhz. We'll have to see. 12Mhz wouldnt be terrible as eVDSL is really there to service the core of towns, not reach areas, they should be done with cabs and network rearrangement.

Lastly I've just glanced at the topic we touched on before, and I think I was wrong with, of the co-existence of ADSL, VDSL, ISDN and PSTN services coming from the MDF outward on main cables.This doc gives a laymans explanation of the potential issues:

The present spectrum allocation proposals use the ADSL downstream frequency band for VDSL downstream as well. From the point of view of the crosstalk between ADSL and VDSL, there is a subtle difference between the two configurations of Figure 1. In the FTTEx* case the presence of the VDSL does not affect ADSL performance, because VDSL power spectral density (PSD) is less than ADSL PSD. Conversely, the presence of ADSL in the same binder may have a serious impact on VDSL performance. In FTTCab configuration the situation is reversed. VDSL signals from the ONU may generate unacceptable noise levels for the ADSL downstream signal, as it becomes heavily attenuated along the path from CO to ONU [1].

*eVDSL AKA FTTEx

We knew part of this already, VDSL can only Vector for modems that the DSLAM is talking to, so ADSL lines running parallel cannot contribute data to reduce FEXT or Far End Crosstalk. They'll slow VDSL lines to some extent, but as theyre weaker by the time they reach the PCP cab it may not be significant, and as VDSL takeup increases ADSL use proportionally decreases. Better vectoring, less "bad lines". Beat your neighbour with a stick until he upgrades

The bad news here is that page suggests the noise for extended reach DSL lines that are already very weak when they pass a VDSL cab. Eircoms CLFMP does mention this though, but its importance Im unsure of:



Theres more that could probably be added here, but I havent the time right now. I'll update it later to fact fix and add anything else thats notable.



Sources:
http://www.comreg.ie/_fileupload/publications/ComReg1472.pdf
http://www.broadband-forum.org/downloads/About_DSL.pdf Kudos to those lads
www.eircomwholesale.ie/WorkArea/DownloadAsset.aspx?id=1166

Hackery

Good post

MBSnr

Am I right in assuming that Eircom could use the 8b profile for eVDSL then? If so the top end speed is 50Mbits/s but the downstream power (20.5db instead of 14.5 db) is higher to overcome direct feed line issues and increase the reach?

ED E

For xTalk reasons they probably want to keep the transmit power low at exchanges, keep it low relative to ADSL which will be in use for the longest lines for a while.

bk

Excellent research and investigation ED E, thanks.

lucernarian

ED E wrote:

Eircom/Huawei have decided that the minimum profile is 7Mb_1Mb whereas ADSL products go as low as 128Kb_64Kb. That means ADSL will prequalify on a line that will barely barely get the tone at the far end. But thats only a small factor, even if they allowed a 1_0.5Mb profile we'd only get an extra few hundred meters based on current charts.

That "extra few hundred metres" may not be true in quite a lot of cases. Not because of problems with the chart but the placing of cabinets is not consistent across towns and cities within Ireland. 2 of the 3 cabinets in Termonfeckin are about 2km away from the exchange and VDSL to all distances there would make a huge difference to dozens of customers and businesses.

BB Forum.org have published a nice summary (see sources) of current xDSL technologies. This is an interesting table:

There's a big problem with that table. For the basic variant of DSL, they report a max speed of G.dmt as 7 Mbit when this presentation from the ITU says it's 8 Mbps and indeed eircom used and still use ADSL1 to provide their "up to 8 mbps" service.


Apparently there was a good reason when eircom limited all their 512 kpbs and above connections to lines reaching about 5.5 km. It was based on the attenuation measurements I think and in my old home, apparently it was 78 dB though with their 1 km = 12 dB rule of thumb, this was an accurate estimate of the distance (which would never qualify). One day, in one fell swoop, eircom decided that the attenuation limit for all lines could be increased from 66 to 72 and then after another couple of months, 78. When we finally got DSL we got a very comfortable 1 mbps with 14 dB signal margin and 53 dB attenuation. You wouldn't think that was possible for me or my neighbours who also get this, by looking at those graphs.

bk

^^^

Yes, these graphs are very conservative and should only be taken as a general guideline of the differences between the different tech rather then exact numbers.

ED E

lucernarian wrote: »

That "extra few hundred metres" may not be true in quite a lot of cases. Not because of problems with the chart but the placing of cabinets is not consistent across towns and cities within Ireland. 2 of the 3 cabinets in Termonfeckin are about 2km away from the exchange and VDSL to all distances there would make a huge difference to dozens of customers and businesses.

The catchment area in between 2000m and 2150m or 2200m is going to be very small. Probably made a cost/benefit call for these lines. They can always add additional profiles in a year or two and reprequal.

There's a big problem with that table. For the basic variant of DSL, they report a max speed of G.dmt as 7 Mbit when this presentation from the ITU says it's 8 Mbps and indeed eircom used and still use ADSL1 to provide their "up to 8 mbps" service.

Apparently there was a good reason when eircom limited all their 512 kpbs and above connections to lines reaching about 5.5 km. It was based on the attenuation measurements I think and in my old home, apparently it was 78 dB though with their 1 km = 12 dB rule of thumb, this was an accurate estimate of the distance (which would never qualify). One day, in one fell swoop, eircom decided that the attenuation limit for all lines could be increased from 66 to 72 and then after another couple of months, 78. When we finally got DSL we got a very comfortable 1 mbps with 14 dB signal margin and 53 dB attenuation. You wouldn't think that was possible for me or my neighbours who also get this, by looking at those graphs.

Eircoms old racks give out 7.61Mb LT cards in ADSL1 exchanges, this is often rounded down to 7Mb. NGN exchanges have 2+ cards and can do the full 8(or 24).

Its conservative on the ADSL distance, but it really can depend on the cable quality and noise.

dbit

Top notch research ED will use that as a baseline in future . Fantastic Job .

lucernarian

ED E wrote: »

The catchment area in between 2000m and 2150m or 2200m is going to be very small. Probably made a cost/benefit call for these lines. They can always add additional profiles in a year or two and reprequal.



Eircoms old racks give out 7.61Mb LT cards in ADSL1 exchanges, this is often rounded down to 7Mb. NGN exchanges have 2+ cards and can do the full 8(or 24).

Its conservative on the ADSL distance, but it really can depend on the cable quality and noise.

They do have racks that allow 8128 profiles though, I had such an ADSL1 connection in or around June 2010 from the Merrion exchange. Specifically not ADSL2. I presume I was connected to a normal Alcatel-Lucent DSLAM. Also this ITU presentation seems to suggest that 8 Mbps is the top speed of the standard also. I thought the 7616 kpbs "max speed" came from the use of interleaving in a particular way (like a high interleave depth) or that the interleave path had a lower potential max speed than using fastpath. I can't remember exactly the difference but I will search the archives later.

ED E

lucernarian wrote: »

They do have racks that allow 8128 profiles though, I had such an ADSL1 connection in or around June 2010 from the Merrion exchange. Specifically not ADSL2. I presume I was connected to a normal Alcatel-Lucent DSLAM. Also this ITU presentation seems to suggest that 8 Mbps is the top speed of the standard also. I thought the 7616 kpbs "max speed" came from the use of interleaving in a particular way (like a high interleave depth) or that the interleave path had a lower potential max speed than using fastpath. I can't remember exactly the difference but I will search the archives later.

Yeah, had a look further:

It should also be pointed out that whilst BTw state that applying interleaving shouldn't reduce your line speed, it does reduce the maximum line rate achievable from 8128kbps to 7616kbps due to the additional overhead required for check bytes.
Note: although BT state 7616 is maximum sync speed with interleaving, many instances of higher sync speeds have been reported by users. This is dependent upon your router being able to support S=1/2 mode which effectively combines two RS code words into a larger logical code word of 510 bytes (ANSI T1.413)

Read more: http://www.kitz.co.uk/adsl/interleaving.htm#ixzz3QmpCOxPn

I've seen a struggling modem falling back to ADSL and using the 7.6 profile, so it might be set as the default profile after a certain number of sync brokers.

ClonNGB

Anybody know if Commreg have approved EVDSL for the direct fed lines ? Where is it now ? Eircom were talking last year about early 2015, but nothing yet. I can't understand why such a delay.

mailsanchu

This is what i have
========================
As yet the eVDSL rollout has not commenced. There are still regulatory elements underway therefore the launch has not occured. We would anticipate that this would commence in March however there is no guarantee as this is outside our control.

Unfortunately I do not have any further information at this point.

bk

Ok, some really good news, I've heard that eVDSL has gotten the go ahead and that the following exchanges will go live on the 18/03/2014:

AFD1
CRT1
LCN1
RUY1
ASN1
CRW1
LHA1
SAN1
BBS1
CTY1
LKD1
SHN1
BCA1
CVN1
MAH1
SKS1
BDT1
DBN1
MGN1
SND1
BLP1
DBT1
MGR1
SRL1
BMN1
DGS1
MHZ1
STN1
BRN2
DNN1
MNT1
THS1
BSE1
DNU1
MSN1
TLR1
BTE1
DSN1
MYN1
TRM1
BUO1
FBK1
NAS1
TWV1
BWM1
FNG1
NWT1
VGA1
CAB1
FOX1
OGT1
WAL1
CEL1
GMR1
PGS1
WST1
CHD1
GRS1
PMK1
CLS1
ISL1
PRP1
CLT1
KDN1
RCL1
CNR1
KGN1
RSL1
CPH1
KLO1
RTD1
CRL1
KME1
RUS1

bk

This is great news as it means a lot more people will finally get access to high speed broadband

Please note, that of course the above date and list could slip or change, no guarantee.

dbit

bk wrote: »

This is great news as it means a lot more people will finally get access to high speed broadband

Please note, that of course the above date and list could slip or change, no guarantee.

You de man well done super find!! where pray tell did you dig this up ?

dbit

Dammit no sign of MRMA balls....... macroom is going to rot.

bk

dbit wrote: »

You de man well done super find!! where pray tell did you dig this up ?

Ah, you know, here and there :P

dbit

i need to live near this one, just for its name sake DBT1

yuloni

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Gonzo

The Dunshaughlin exchange goes live in 3 weeks.

Even tho i'll never be able to benefit from the eVDSL or current eFibre rollout, I have noticed my speeds have increased again over the past week. Up till a month ago I was getting syncing between 7 and 8.5meg, then 2 weeks ago started syncing at 10.5meg and this week its gone up again.

now I am getting:

Speed: 11606 kbps/670 kbps
Line Attenuation(Down/Up): 38.9 dB/ 19.1 dB


This is an increase of approx 3megs on average over what I used to get up untill recently.

yuloni

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yuloni

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ED E

BK is like little finger (GoT reference), always in the know

dbit wrote: »

i need to live near this one, just for its name sake DBT1

Donnabate, not sure you do! :pac:

yuloni wrote: »

This post has been deleted.

If theyre all going RFO that soon it means the racks are already sitting there, eircom has been chomping at the bit for this starting gun. Now we're off to the races.

Gonzo wrote: »

.. syncing between 7 and 8.5meg, then 2 weeks ago started syncing at 10.5meg and this week its gone up again.

now I am getting:

Speed: 11606 kbps/670 kbps
Line Attenuation(Down/Up): 38.9 dB/ 19.1 dB

If your sync rate exceeded 8.1Mb then they haven't changed your profile code, and probably not the port.

Either field work has improved your loop, or the more likely, the line cards in the exchange are emptying out rapidly as most of the area moves to VDSL. Bye bye crosstalk.

Update:
Just to add, thats only 74 Exchanges listed for DF. 74 of 900+, theres a lot still to do, but its a very good start.

dbit

Nothing, absaloutley nothing for Cork Macroom eat me Smearcom .

kaizersoze

I suspected something was about to happen. 5 or 6 KN vans aroung Ballinasloe (BSE1) for the last week or so.

bk

ED E wrote: »

BK is like little finger (GoT reference), always in the know

I just wish I had his harem of ladies

ItHurtsWhenIP

yuloni wrote: »

This post has been deleted.

If the exchange dots don't show up, does that mean they don't love us? :rolleyes:

ED E

MMFITWGDV wrote: »

If the exchange dots don't show up, does that mean they don't love us? :rolleyes:

Means you're likely talking post 2016.