FTTC DLM and profiles

I escaped the tyranny of BTw ADSL speed profiles many moons ago; first by moving to LLU then later to VM cable.

Today I've moved to FTTC. I'm presuming there will still be constant DLM in place increasing the target noise margin if necessary to maintain stability and probably with a similar long recovery period if conditions improve. BUT does FTTC have the same annoying download speed banding and long penalty period after recovery from a poor sync event which I remember from the 8Mbps ADSLMax BTw product or does download speed now instantly follow sync (apart from overheads) in the way LLU ADSL products do?

21CN and fibre have instantaneous changes to the IP profile
- it is a pity the Plusnet system takes rather longer

Thanks for the info.

In reply to a post by Oldjim:

<snip>
- it is a pity the Plusnet system takes rather longer

I've forgotten the reason for it still being there?

I've a feeling it may be an integral part of the prioritisation system, as that needs to know the line capacity to decide what to do in real-time. That's a pure guess by me.

As the BT IP Profile is 0.9679 x sync (which absorbs most of the overheads), and the Plusnet copy takes that and AIUI rounds to the 100kbps below, there isn't much loss. The problem is the occasions on which it fails to update.

FTTC in general doesn't seem to me to have many modem disconnections, compared with ADSLx. So again, it's less of an issue.

Edited by RobertoS (Thu 19-Dec-13 23:22:40)

So does this mean my download profile is stuck (been like this the last 10 days or so), as it has not increased to match the actual sync speed (even though the upload profile has)?

Max: Upstream rate = 5791 Kbps, Downstream rate = 28628 Kbps
Path: 0, Upstream rate = 5754 Kbps, Downstream rate = 24725 Kbps

Those figures are nothing to do with the IP Profile.

The BT (near-master) version can be found by running the BT Performance Test (ignoring the silly red instructions for this purpose), and continuing to the Further diagnostics at the bottom of the results page.

The Plusnet "near-copy" is to be found in your Member Centre >> Connection settings >> High speed broadband. It is the Current line speed. You are probably looking at BT = 23.9 and Plusnet at 23.8.

Note that your BT upstream IP Profile will be 10 if on 40/10 and 20 on 80/20, quite independent of your sync speed. Plusnet do not hold a copy of that.

Edited by RobertoS (Fri 20-Dec-13 02:20:19)

So what exactly is 'Max' connection speed, I thought this was your actual sync speed and the profiles would be set at the profile closest to this ?

In reply to a post by timh:

So what exactly is 'Max' connection speed, I thought this was your actual sync speed and the profiles would be set at the profile closest to this ?

No, "Path" is the actual sync speed, "Max" is a theoretical maximum and can be ignored for most purposes.

In reply to a post by Oldjim:

21CN and fibre have instantaneous changes to the IP profile
- it is a pity the Plusnet system takes rather longer

Yep, it does. My IP Profile on plusnet side haven't been updated to match BT end for 14 days and I give up waiting and did try twices rebooting router but it doesn't work and I posted on plusnet community forum and the staff had manual adjusted plusnet profile no problem at all.

I don't know if my plusnet ip profile working or not. Sometimes it quicker to match BT end, sometimes it take longer to match BT end, the worse one is 14 days waiting from 15.8Mb to 16.2Mb.

Edited by adslmax (Fri 20-Dec-13 12:25:00)