It does seem that 20 is the magic number, not 37!

It could be a "no cap" figure and therefore works on FTTC as well as ADSL2+. Whereas 37 is really odd, as discussed.

By the way, in one of the Community threads about it I saw someone say the BT 38717 allows for ATM overheads out of the 40000 sync.

There is no ATM in FTTC connections. I don't think there is any in the backhaul either for any WBC/WBMC service. Possibly IPSC.

In reply to a post by RobertoS:

It could be a "no cap" figure and therefore works on FTTC as well as ADSL2+. Whereas 37 is really odd, as discussed.

That was my theory, but Adam's latest reply on the community forum suggests it's not that simple (or that he doesn't want to admit that it is!)

In reply to a post by RobertoS:

By the way, in one of the Community threads about it I saw someone say the BT 38717 allows for ATM overheads out of the 40000 sync.

There is no ATM in FTTC connections. I don't think there is any in the backhaul either for any WBC/WBMC service. Possibly IPSC.

This is all a bit over my head, but if true it makes me wonder why we can't have the full 40 meg.

In reply to a post by kasg:

In reply to a post by RobertoS:

It could be a "no cap" figure and therefore works on FTTC as well as ADSL2+. Whereas 37 is really odd, as discussed.

That was my theory, but Adam's latest reply on the community forum suggests it's not that simple (or that he doesn't want to admit that it is!)

Before FTTC, 20M was the "no-cap" profile figure for ADSL2+, which (of course) almost no-one ever got anyway.

During the FTTC trials, PN set the 20Mb profile manually for everyone involved - and it may well still be being used that way for people in the FTTP trials still.

I suspect that PN have since built a proper "37M" profile for the live service of FTTC, and put people on there. The question remaining is whether they've built the right thing. Or worse - they've built what they think is the right thing, extrapolated from the old profiles, and now find that every profile is ever so slightly off. Or simply not applied it properly to some subscribers.

In reply to a post by RobertoS:

Whereas 37 is really odd, as discussed.

Plusnet was an ISP that chose to label ADSL2+ as "up to 20Mb", as a deference to truth over marketing hype (rather than just follow the "up to 8" that was almost purely based on the technology numbers, and not reality).

That would also explain why the "20Mb" profile was the previous top, "no-cap" profile.

Given the attitude they applied there, a "37Mb" profile is merely consistent.

In reply to a post by RobertoS:

By the way, in one of the Community threads about it I saw someone say the BT 38717 allows for ATM overheads out of the 40000 sync.

There is no ATM in FTTC connections. I don't think there is any in the backhaul either for any WBC/WBMC service. Possibly IPSC.

This is all a bit over my head, but if true it makes me wonder why we can't have the full 40 meg.

Definitely no ATM, but there is still overhead. IIRC it is just the overhead of ethernet and PPPoE, rather than ATM and PPPoA.

Given the attitude they applied there, a "37Mb" profile is merely consistent.

Possibly yes, but not really logical given that the majority of FTTC users seem to be on 38700+ IP Profile it doesn't seem appropriate. We've already seen that, on speedtest.net at least, many get 37.5Mbps or more.

On ADSL2+ it was fair enough as extremely few would get 20Mbps IP Profile, never mind throughput.

If it is an "uncapped" setting all they need to do is alter the text displayed to say 38Mbps, or better still 38.7Mbps, in line with their new WBC "Profile copy" rounding. Then everyone understands.

Re ATM, I agree there are overheads involved. I was just pointing out the error, as it only takes half-a-dozen repeats/quotes of that sort of thing and it becomes a facttruism.

Meanwhile, over on the community forum, the latest mystery is why from time to time, I now get a "17Mb" session!