Quick question

Will the new checker updates over the next weekend show availability for people who live too far away from a cabinet? i.e; will those who are below the 5Mbps threshold see availability for a product due to the new profile change?

Cabinet & exchange is enabled however too far away from cabinet.

Cheers!

The extra frequencies are at a higher frequency so will make no difference to those on the longer cabinet to premises lines.

If there has been an error in the calculations this might get corrected, but it might introduce more new ones.

What estimate do you get? I'm not certain but IIRC ADSL24 and Aquiss already have some customers on the 5Mbps product who had lower estimates. On the basis that if it didn't connect above 5Mbps it wouldn't be completed, similar to the 15Mbps one.

Hi guys,

I know that such companies will order a product which is below the FTTC 'threshold', but it isn't showing anything on the wholesale checker.

Before the cabinet was enabled, it showed I could get FTTC with 500Kbps down & 100Kbps up (or vice versa), however when it was enabled, it disappeared. Happened to a few other people.

While the extra frequencies are not usable at long distances, the bandplan changes affect some of the lower frequencies - mainly in the 3-3.75MHz region.

Those changes are going to be useful to many longer distances.

However, the OP later mentions old speed estimates of below 1Mbps. I suspect that the distance involved for those speeds won't be able to benefit from the bandplan changes either.

Hi there,

I'm currently receiving 5Mbps however? This wouldn't make a difference would it?

Cheers

Jack

Also - do you know when those changes go into effect?

Please can we have the post code, and the cabinet number you believe you are on? So the percentage of lines can be checked. With a current 5Mbps it seems strange that the estimate is low or missing.

BT670ES & cabinet number 1.

Cheers!

Jack

(btw, I've checked the spreadsheet and it said 100% of lines on cabinet 1).

Mild 4-letter word beginning with a letter of the alphabet. I was forgetting you are in NI.

I expect you've been through this loop before? I was too lazy to check back, but of course know your nick as well as you know mine .

Anyway, Phase 5a which I thought was complete long ago. Times 2.21 speed increase, which means you won't show up on the Infinity tester but should on the Wholesale one. Given your current connection speed, you should be able to get the 5Mbps estimate product from at least three suppliers, if you can get anyone to talk helpfully. ADSL24 and Aquiss spring to mind. Though even they may have trouble, as the ordering system may tell them to get lost. BT Option 3 with Fibre is another such, but I don't think they have humans there to talk to. Just script-monkeys.

Have you tried and failed to get anywhere with anyone?

Edited by RobertoS (Tue 24-Jan-12 22:53:03)

Hi Roberto, yep! I'm the guy with the ping/latency issues a while ago... I remember you surely, thanks for all your help.

Yeah - I've been checking the wholesale checker for the past year now... not a thing showed up (and I don't know why I keep checking every day).

Have been to ADSL24, Aquiss and a few others & they said that if it isn't showing on the checker, they can't do anything.

Cheers

Jack

That has to be pathetic . I can't think of a way round it though.

Agreed.

Still seems daft that exchange-based ADSL is giving 5Mbps, but it won't come up with something better for a cabinet-based setup. Perhaps it is a problem caused by power-reduction in the cabinet.

How much closer does cabinet 1 get to the house compared to the distance to the exchange?

ISTR the cab is just outside the exchange

Ah. I've lost any suitable VDSL2 graphs to compare with this one, ie straight speed against attenuation. There's at least one that I've seen in the past, I think it had it by profile. Unless that one did speed against distance.

Yeah - exchange is just about 2 miles away & cabinet is around 20 metres from the exchange.

I know obviously I wouldn't benefit that much with most of the distance still being copper but there is no ADSL2+ / LLU at my exchange so I can't benefit from speeds higher than 8Mbps... and as I'm syncing with interleaving on at 7Mbps, I should be able to expect the same speeds as LLU/WBC 21CN?

Cheers

Jack

In reply to a post by RobertoS:

Ah. I've lost any suitable VDSL2 graphs to compare with this one, ie straight speed against attenuation. There's at least one that I've seen in the past, I think it had it by profile. Unless that one did speed against distance.

I've got another of those pesky Ericsson Vectoring documents, this one a PDF of some powerpoint slides - with some of the raw research on crosstalk and vectoring.

The graph on page 9 seems most appropriate to our deployment: 0.5mm copper, with the 17a profile (the earlier graphs are for 0.4mm copper).

The red line should represent the worst case behaviour of lots of crosstalk going on - and is probably a good prediction for what the DSL checker will start reporting next week.

I guess our experiences will probably lie midway between the red and blue lines.

In reply to a post by RobertoS:

Ah. I've lost any suitable VDSL2 graphs to compare with this one, ie straight speed against attenuation. There's at least one that I've seen in the past, I think it had it by profile. Unless that one did speed against distance.

Aha - another Ericsson document, this time with the graphs you probably wanted...

Page 7 shows how speeds vary over distance for profiles 8d, 17a and 30a. Again, it seems to be the case of maximum crosstalk, but it shows that VDSL2 seems to drop to ADSL2+ performance after around 1800 metres - or just over 1 mile.

In reply to a post by jdowning640:

Yeah - exchange is just about 2 miles away & cabinet is around 20 metres from the exchange.

I know obviously I wouldn't benefit that much with most of the distance still being copper but there is no ADSL2+ / LLU at my exchange so I can't benefit from speeds higher than 8Mbps... and as I'm syncing with interleaving on at 7Mbps, I should be able to expect the same speeds as LLU/WBC 21CN?

My old line, on 20CN, was borderline 8128 without interleaving, with a 30.5dB attenuation - which Kitz predicts to be 2.2km. With 21CN it gets around 13-14Mbps sync.

At 2 miles, you will be worse, but I'd still expect maybe another couple of Mb on top of ADSL1. As I pointed out in the previous post, VDSL2 seems to run out of advantage at around 1 mile, so I wouldn't expect it to be any better than ADSL2+ for you... but that still ought to come in over the 5Mbps threshold.

Does BT use vectoring or looking to use vectoring? seem to be quite an automagical tool to help boost the speeds.

Yes. In one of their annual results documents, they recently mentioned the 17a profile change to get the "up to 80Mbps" service in 2012, and then mentioned "other technologies" to take it to > 100Mbps - but in a graphic to show future availability, they mention Vectoring by name.

They don't give a date for it though... I suspect it will have to wait until the manufacturers get a competent implementation first.

I would suggest 2014 for vectoring, i.e. get the bulk of their own roll-out done, and the BDUK stuff well underway

I remember us originally contacting Openreach for you and their reply unfortunately stated the reason:

"It all lies with the cab being close to the exchange and 3.5km away from the eu's premises. Although the E side is now delivered over fibre, the cabinet is very close to the exchange and so it means there'll be no improvement in the current ADSL speeds because the D side is still copper and a very long line."

Therefore, FTTC is not showing available because the service will not work any better and could even be worse. Sorry - I know it's not great, but that's the problem!

Yeah James, I appreciate you doing that for me even though it took a while for BT to reply to you guys!

Can someone explain what vectoring is and if it could help me?

Cheers!

Vectoring is a method of noise cancellation. It measures and monitors all of the lines in a cable bundle and for each line injects an equal and opposite signal to the predicted noise that will come from crosstalk from te other lines. Not perfect but if managed properly will improve the SNR.

For a very long line, will it help much? Comparing VDSL and VectorVDSL it is unlikely as the attenuation at the higher frequencies will not change and although a few more carriers might work the improvement will not be great if any. And with the band plan and positioning of upstream and downstream within it compared to ADSL, the result could be worse.

On a line of 3.5km from cab to property, then ADSL/ADSL2+ would seem best bet