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[WWWombat]

Yes, that graph has its strange points. I like it because it makes you realise that there is a range of effects, and some randomness. Nothing about crosstalk is perfectly predictable.

There are others around, and can usually be found in articles and presentations on vectoring - because that is the common "solution" to crosstalk. A shame we're not getting it widely deployed here.

By the way, there is another article here, that talks about the impact of crosstalk:
http://www.increasebroadbandspeed.co.uk/2014/vectoring-crosstalk-crisis

And I found a "heatmap" in this presentation on Vectoring trials in Denmark, page 8:
https://marketingwholesale.tdc.dk/assets/tdcws/1411340050.pdf

That presentations has a graph showing speed improvements in the trial, on page 10. The gains aren't necessarily as high as in the BBF document - presumably with only 20 real customers, spread out geographically, there wasn't as much crosstalk as you see in some of the lab trials.

[ejs]

I was surprised fig. 6 in MR-257 showed vectoring working fairly well, despite only slightly over half the lines were using vectoring. I thought vectoring worked best if all the lines are vectored, but the vectored lines seemed to be doing pretty well despite plenty of non-vectored lines.

The next graph in MR-257, shows a drop of about 10 Mb, from 15 other lines to 49, no vectoring.

[kitz]

Last year I was quoting that the average speed lost by members of this forum through crosstalk appeared to be in the region of 15-20Mbps.  This is a rough ball park figure based purely on the stats of those who were monitoring their lines. 

Bear in mind that crosstalk affects the shorter lines the most and these are the ones who tend to lose the most speed.  In the few years since Ive had fttc Ive lost just slightly over 25Mbps from my headline rate due to crosstalk, some have lost more than that.     

[Chrysalis]

Yeah when I said averages are in 10s of mbits second thats also taking into account on the trial average initial speeds were high also.  A vdsl line syncing at say 20mbit without crosstalk isnt going to lose 10s of mbits to crosstalk.