The Netflix test doesn't do too badly for me; usually over 100Mb anyway. It only used three threads when I checked, which backs up what I was saying about it being route-dependent. There are a handful of other CDNs that perform OK, it's just *most* downloads are poor.

The common factor amongst poor downloads seems to be going via a London interconnection point. The Netflix test goes to IP addresses mostly inside VM's own network and closer than London (Manchester and Leeds). The third does seem to go via London but peers with VM, and handles less traffic than the others anyway.

I'm not sure why a CMTS issue would be route-dependent, but it's just something affected connections seem to have in common so far.

I know I'm fed up with getting sub-ADSL speeds on a '200Mb' package!

Still no movement on this sadly, and it was really bad last night with even Youtube struggling, and the fast.com test was below 30Mb.

I wonder if TBB staff would consider looking in to this e.g. if anything is obvious on speed test logs from VM customers in general, or from certain postcode areas?

Unfortunately I can't find a way to complain directly to Ofcom, only ADR thourgh CISAS which would probably just result in contract termination, but I'd much rather get to the bottom of it as before this problem my VM connection was great.

Of the major providers Virgin Media has the biggest swing between peak and off-peak speeds, something like 15-20% on average, which means for some it will be significantly worse. We can split Virgin Media into its areas by use of the reverse DNS name but this means test volumes are then too low to be reliable for looking at peak versus off peak issues.

Virgin should be well aware of the networks performance just the people you talk to may not be privy to the full detail. Our tester along with the fast one is one of the few that is deliberately set to be fairly sensitive to performance issues. The SamKnows testing was mentioned as something Virgin Media wanted reviewing as they were saying it was not showing the right speeds on their 200 Mbps service, but this might actually be the number of threads running again - so will be interesting to see how Ofcom handles this when they publish their next round of results.

Unfortunately it's much worse than 20% for me; on the 200Mb package we get anything between 5 and 20 at peak times lately. The fast.com test tends to perform better than yours and the speedof.me test but I suspect it's due to local peering with Netflix avoiding what seem to be troublesome London interconnection point routes.

Yeah I understand it's a difficult thing to prove from your end, it's just a thought. But I really hope Ofcom don't further relax single thread performance requirements as it shows Virgin Media in a much better light than is fair. And Samknows barely touch single-thread as it is - I did contact them and mentioned this issue and the person I spoke to said re-introducing it is something they're investigating but I really hope they go ahead with it.

The way things are at the moment, Virgin can sell a service which is in practical terms slower than ADSL as a 200Mb product and get away with it because of speedtest.net's curious testing methodology.

As much as I try and complain to either VM support or on their forums, I'm just met with utter silence or the assertion that speedtest.net looks OK so it must be an 'off-network problem' which is ridiculous.

funny you should mention the service deteriorating since the vivid upgrade. Mine was exactly the same,

Mine went from a consistent 90 or so mbps+ to anywhere from 1 to 10mbps. Virgin refused to admit there was a problem.

From the 8th Of July, my virgin media superhub will go dark for good. They even had the cheek to charge me an early disconnection fee, something which was far easier to tolerate than the frequent slow speeds and repetitive phone calls.

poor show vm.

I don't know which is worse, that they know a problem exists and refuse to fix it, or that they genuinely aren't aware of a major problem with their network in some areas.

i have no clue

bit like virgin media really.

Yeah fast will be accessing the CDN which given the size of Virgin Media should be on their network.

It's just so utterly frustrating having them constantly stonewall me when I try to explain the problem and ask if/when it's like to get fixed.

Like you say, surely the networks team must be aware of something like this? But according to the forum support, the networks team is telling them something like 'single thread can be variable so we only use multi-thread'. Yeah, that's useful! Not...

The real test is what services are being impacted by the issue, and highlighting what is impacted from actual applications.