VDSL 80/20 Cap

Just curious ....... I'm lucky enough to have a OR FTTC cab in spitting distance and get "Full Speed". My line though says that it can cope with 128 Mbit/s / 28.7 Mbit/s but it's capped at 80/20. I get that BT use VDSL2 with a 17a profile and this has a max downstream rate of 100 Mbit/s. I've friends is Europe and Australia getting 100 Mbit/s from FTTC VDSL2 17a with real world rates of 94 Mbit/s download. Is this 80 m/bit cap a technical one giving some other benefits or a product marketing feature?

With G.Fast now being rolled out and improvements being worked on, I doubt Openreach will lift the 80/20 caps on VDSL2 as it would then cut into the G.Fast ranges.

In reply to a post by lee111s:

With G.Fast now being rolled out and improvements being worked on, I doubt Openreach will lift the 80/20 caps on VDSL2 as it would then cut into the G.Fast ranges.

So are you saying that the 80 Mbit/s cap is a product marketing feature and not a technical one?

Yes, but you already knew that, given operators on the continent don't have it capped at 80/20

Edited by deleted (Sun 09-Jul-17 19:42:03)

Nope, Openreach will never uncapped VDSL2 80/20. The only way to get uncapped is to order FTTPoD or wait for G.Fast.

Edited by adslmax (Sun 09-Jul-17 20:52:57)

But their FTTPoD offering is capped also ??

As is G.Fast right?

In reply to a post by lee111s:

Yes, but you already knew that, given operators on the continent don't have it capped at 80/20

I know elsewhere they offer higher speed VDSL2 17a. BUT what I don't know is why ....... Is there an upside to offering 80/20 e.g. does the lower power reduce crosstalk so giving people further away better speeds? Is the cap reason a marketing one. ie you can claim that 20% off people get our top speed or some such thing? I'd just really like to know what the rationale is for 80/20.

Because so few are likely to get beyond 80 Mbps sync that its not worth it as providers are not going to be able to exploit it in marketing due to advertising rules that exist in the UK

Likely a combination of both a small number of customers would benefit (and yes likely less power needed) and the fact that G.Fast has always been the next step and will offer speeds of 81-330meg (Openreach/Wholesale won't offer it if the speed estimate is below 80mbps as far as I know).

I think only 10% of lines are close enough to achieve 80/20, only 5% could achieve 100/25 on VDSL2 17a.

In reply to a post by lee111s:

Likely a combination of both a small number of customers would benefit (and yes likely less power needed) and the fact that G.Fast has always been the next step and will offer speeds of 81-330meg (Openreach/Wholesale won't offer it if the speed estimate is below 80mbps as far as I know).

I think only 10% of lines are close enough to achieve 80/20, only 5% could achieve 100/25 on VDSL2 17a.

Does that mean that the end product will be different to the trials, as with the trials people with lower than 80 meg have been able to get G.fast, which is why they have different speed packages like 200 meg and 330 meg?

I've no idea what will happen after the trials. I guess this is why trials are done, to see how technology works in real world environments, not just lab based circuits.

The two speed tiers for G.fast as it stands at the moment will be up to160mbps and up to 330mbps.

Are you saying there are people trialling G.fast and syncing lower than 80meg on G.fast? Or are you confusing the 80meg I mentioned with VDSL2 speed estimates?

In reply to a post by lee111s:

I've no idea what will happen after the trials. I guess this is why trials are done, to see how technology works in real world environments, not just lab based circuits.

The two speed tiers for G.fast as it stands at the moment will be up to160mbps and up to 330mbps.

Are you saying there are people trialling G.fast and syncing lower than 80meg on G.fast? Or are you confusing the 80meg I mentioned with VDSL2 speed estimates?

I'm saying that people that have a lower than 80meg estimates for VDSL2 have been on the trial for G.Fast, but this might be to see how low the speed can be for it to be affective for G.Fast

My point was that if the estimates for G.fast are below 80meg then it won't be offered (as far as I know, I'll try and find the article I read it on).

Edited by deleted (Mon 10-Jul-17 12:20:50)

Based on what we've seen people with estimates for VDSL2 in the 65 Mbps and region stand to benefit from G.fast, but just not the full benefit.

i.e. G.fast does not need you to have been maxing out the VDSL2 already to actually benefit

G.fast will be a failure for many of us for those who have long distance away from the street fibre cabinet to the property will be no benefit at all.

G.fast work best if u live below 50 meters away from the cabinet for maximum speed up to 330/50. (probanly only 3-5% will get it)

A further more than 50 meters will lose massive speed drop from 330/50 to around 100/20. (95% will getting this type of speed)

For my line distance to the street cabinet approx 250 meters are probably getting 81-99 Mbps downstream and 20Mbps upstream. So, G.fast will be a waste of time, money etc. BT should roll out Fibre To The Property instead!

Edited by adslmax (Mon 10-Jul-17 17:05:17)

Go and re-check the Openreach trial data.

330meg should be achievable up to about 200meg.


200meg+ at 250m and 100meg+ at 400m is not out of the question.

Don't forget that G.fast is still a very new technology with many more improvements in the pipeline. Just like ADSL was the original technology, which was then massively improved with ADSL2 and 2+.

Edited by deleted (Mon 10-Jul-17 17:15:49)

Well I do hope you are right!

Indications are that you are being very very pessimistic, yes full fibre would be best and ideal but issue is the time to install it all...

G.fast does seem to be doing roughly what it says on the time so far, so yes it has a quick distance drop off, but it should scale very quickly and allow speed competition with Virgin Media.

So while full fibre are the key words to make people happy, if you add might take 10 years to roll-out to you then people are less happy.