Right now? The best answer is through external knowledge of the line, chatting to Openreach engineers, or watching for how the estimate has changed over time. Tying the estimate to actual sync speed would help, alongside monitoring of the history of the sync speed and error rates.

The same information for a number of lines would help improve guesswork into solidity.

Rather like VDSL2, to be honest, and the way we figured things out 6-7 years ago.

I wouldn't put too much emphasis on the checker at this stage.

There are less than 500 people on G.fast at the moment, so there's not enough live data to give realistic scenarios for speed in the checker.

I fully expect our table to get some regular tweaks as the year progresses, difference in 2017 compared to 2009 for VDSL2 is people are now expecting all the answers on day 1

I notice you've updated the "cumulative percentages" covered by different distances for VDSL2, which has fed into that table for G.Fast.

Some of the changes seem huge to me. For example, the 100m distance has increased by around 6%, but the 400m distance has changed from 45% to 68%.

The first change seems plausible, but the second one is huge. Just that raw number would suggest that 23% of lines have been affected by infill!

Has it really improved that much?

Or have you audited the baseline figures too? They were based on the Sagentia/Ofcom report from 2008, right?

+1

Baseline was the 2008 report, and now its our figures, since things have changed so much using decade old figures makes no sense

In places like Glasgow and Edinburgh there have been a LOT of EO areas gaining cabinets where lots of people are on top of the cabinet, and the practice of often doing 1 new cabinet outside the exchange in Scottish villages is making an impact too

If the entirety of Scotland was EO, and all converted to cabinet-based, and be complete, it would still affect less than 10% of lines!

I need to think of some sanity checks here. 23% feels too high a number.

is that a table for g.fast (I know it's estimates). Intrigued as I'm around 450m from cab - was getting about 35/7 sync on VDSL2 + HG612 but I jumped to virgin (200/20, could go higher).Good to consider what options may be around in the next few years, I'm guessing a doubling or so on fttc, but nothing like the close distance speeds

I doubt you will get any faster with g.fast than you did on VDSL. Current G.fast plans are going to be a big disappointment for a lot of people

In reply to a post by witchunt:

I doubt you will get any faster with g.fast than you did on VDSL. Current G.fast plans are going to be a big disappointment for a lot of people

People certainly need to be pragmatic. If you aren't getting full 80Mb sync due to loss you aren't going to get anything better out of technology that runs at higher frequencies.