well see my thread seems I may get a fix as BTw have recognised it as a fault.

Well well well, at about 00.30 today the connection dropped for a few minutes then came back synced 6Mbps higher at 66969 - I'd pretty much given up on that happening now after two months. What is odd is that the SNRM is only 4.3. yet the attainable is 73472 - I would expect it to be lower than the sync. Interleaving is still off.

there is a banding that caps at 67 which might explain the gap between sync and attainable.

however the attainable is odd considering your snrm.

a guess is yopu had temporary improved line conditions which would have got you a approx 73mbit sync but you got 67mbit due to banding, and when your temporary improvement stopped the attainable seems to have malfunctioned somewhat, only a weak guess tho.

It could be that the "temporary improved line conditions" were caused by a DSLAM outage.

If the modems resynced before (some of) the neighbours, it could have the faster speed, but the SNRM value drops as more modems gain sync.

yeah and ironically the banding has probably saved the sync, as I think he wouldnt have held onto 73.

Gone from full 79999kbps to 65500kbps. Not sure how full my cab is but BT are there literally every day. All of my neighbours appear to be on FTTC now.

I'm 300m from the cab. Attenuation is 12db.

Edited by wolvesmad (Fri 12-Sep-14 10:21:57)

Here is a graph of my line stats since the beginning of February 2014. Make of it what you will with regards to cross talk but I definitely have been affected I'd say.

Note I did have an issue with the cabinet being broken between Jan and April.

Dotted = Max attainable line speed.
Red = Downstream SNR
Orange = Upstream SNR
Blue = Downstream Sync
Green = Upstream Sync
Black = Uptime

Stats image: http://i.imgur.com/Jiitjyg.png

Edited by deleted (Fri 12-Sep-14 11:38:33)

In reply to a post by Ignitionnet:

Given Openreach are hopefully, at some point rolling out vectoring I thought it'd be interesting to see how people are being affected by crosstalk.

Also might help give some indication of the kind of loss people who aren't hitting full rate can expect. I can imagine BDUK enabling a fair amount of longer lines.

Here's Mine:

Only one on cabinet.

150+ lines down.

I have started to process the PSD information that we capture during a PQ test and its quiet interesting that you can see the VDSL cross talk on the trace, see this example: http://imgur.com/HBtANBQ

In reply to a post by Chrysalis:

yeah and ironically the banding has probably saved the sync, as I think he wouldnt have held onto 73.

No, probably not, so pretty happy with 67ish for now.

In reply to a post by kasg:

No, probably not, so pretty happy with 67ish for now.

Well that didn't last - I had to power off the modem (well, strictly speaking I didn't have to, but I was trying to eliminate the possible cause of a connection problem I was having) and when it came back I was back to 60M actual and attainable with an SNRM of 6ish. So it seems that the higher speed was due to some failure that caused a resync of my and possibly neighbours' modems resulting in less crosstalk and therefore a higher speed. I still don't really understand why the attainable speed held at 73M throughout. I might try a resync at the sort of time it happened before - maybe a neighbour is powering off overnight.

Edit: my problems that caused me to reboot the modem were almost certainly due to a Plusnet outage (82816).

Edited by kasg (Mon 15-Sep-14 16:31:16)