Broadband News

Sky has wrists slapped over fastest peak time claim

The ASA has told Sky to never show an advert again in its previous form and if it uses Ofcom speed test results to ensure it is made clear the testing refers to fixed line performance only.

This latest ruling was made after BT challenged a "Fastest peak time speeds measured by Ofcom" in a Sky advert and raised the issue with the ASA. Given the advert claim was based on the testing by SamKnows for Ofcom the presumption by many will be that BT got it wrong and people may find it odd that the ASA upheld the ruling. The devil though is in the detail and below is what Ofcom had to say about Sky and peak time speeds in its last speed report (November 2014 data).

"Broadband can slow down at peak times (between 8pm and 10pm on weekdays) due to a large number of people going online at the same time. This is known as network ‘contention’.

Sky’s ‘up to’ 38Mbit/s broadband showed the effects of network contention the least, with 96% of panellists taking part in Ofcom’s research receiving 90% or more of their connection’s maximum speed at peak times.

EE’s ‘up to’ 38Mbit/s broadband performed the least well, with 7% of panellists receiving 90% or more of their maximum speeds at peak times.

Cable services also suffered from slowdown at peak times. As Virgin Media delivers maximum speeds faster than its headline ‘up to’ speeds, peak time slowdown for its services is also measured against headline ‘up to’ speeds. The proportion of Virgin Media panellists getting at least 90% of their headline speed at peak times were: for Virgin Media’s ‘up to’ 50Mbit/s broadband it was 100%; for 100Mbit/s it was 59%; and for 152Mbit/s it was 33% in November 2014."

Extract from Ofcom February 2015 report

The key is that Ofcom is saying Sky showed the least effects of network congestion, which is different to the claim of the advert which was "Fastest peak time speeds measured by Ofcom". In the Ofcom report Sky did have the highest speeds on the up to 38 Mbps FTTC based products, but crucially this table does not feature normalised results - i.e. no correction has been applied to compensate for variation in line length/quality, something which has been done for the ADSL2+ speeds for some time. Why Ofcom does not correct for cabinet distance is unknown and with a panel size of 1,711 connections spread over 14 services in the peak time panel it should be possible to do so. Though if going to normalise FTTC speeds, you also need to know something about the testers in home wiring, e.g. a bad star config, slow speeds due to modem on an extension or the ideal set-up of a master socket faceplate filter. Another issue even if the data is normalised is whether maybe 100 connections for a service is a wide enough sample to detect the variation in congestion that often varies by region or even town/exchange/cabinet area.

Looking at our speed test results for February 2016, for all connections on the big five providers (we could talk about others but sample size means we are not confident enough to give peak versus off-peak figures) the peak time speeds (6pm to midnight) as a percentage of daytime speeds (7am to 3pm) were BT 99.3%, Plusnet 100%, Sky 90.9%, TalkTalk 95.5% and Virgin Media 81.3%. Of course we don't have all those who do run our speed test running it at both peak and off peak periods, but the volume involved means we observe a much wider geographic sample than Ofcom. The Plusnet results have been a little odd as at peak times some months they exceed their off-peak speeds and this is thought to be down to the way traffic management is utilised across the Plusnet network. In an ideal world there would be a way to combine the Ofcom testing and our data so that observation of what the public see and the formal Ofcom testing produce could be discussed and used to better inform the nation as a whole.


The main thing I take from this is how shocking Virgin Media's congestion is.

  • _Mike_B_
  • over 4 years ago

The problem with broadband as a product is that you don't know what you will get in terms of usable throughput until the product is installed. Installation will likely be just after the free cancellation period expires. Unlike almost any other delivered product where you have 7 days after delivery to cancel.

You now get sensible estimates of connection speed when you place an order. It is about time that the ASA and Ofcom ensured that you also get sensible estimates of usable throughput, at any time of day.

  • Michael_Chare
  • over 4 years ago

@_Mkike_B_ yeah, been an open secret for a while now. It's enough to make anyone jittery :)

  • AndrueC
  • over 4 years ago

yeah looking at results they are bad-
ohhh missed that these results are from December 2014 so way out of date now !!

  • gsituffers1
  • over 4 years ago


you can't really get estimated speeds on virgin as speeds on the next 2-3 streets will be likely very different as it be fed via another FTTN cab (not the small ones) as your speed is given due to what profile you have been given (you do get 55/77/110/160/168/220 as they give you 10% on top of your speed) and how utilized the upload and download each channel is at

  • leexgx
  • over 4 years ago

problem with virgin is that not reacting to peak time congestion and planning for a cab to have more cards fitted a lot of the time they ignore it witch is a problem as it can turn into high ping and packet loss when upstream is past 60% congestion

when DOCSIS3.1 comes and people replace their modems they have access to 16 channels 3.0 or 3.1 network as i have seen one at a business premise which was on 3.0 network but using 16 channels

  • leexgx
  • over 4 years ago

If you don't want to suffer network contention at busy times, and I don't, then you need an ISP like AAISP that will ensure they have sufficient capacity but it will cost more. The big ISPs like Sky and BT retail won't spend the amount needed on a product they virtually give away for free. In short, if you're only paying about £5/month for broadband don't expect your ISP to care about congestion.

  • Teefenn1
  • over 4 years ago

ASA decisions like this will continue to allow VM to ignore congestion without impact on marketing.

  • chrysalis
  • over 4 years ago


- Maybe Virgin don't plan "for a cab to have more cards fitted" as there are no cards in the cabs. They're in the CMTS at the head-end or hub site.

- The business hub you saw was a Hitron CGNv4, which is Docsis 3.0 only.

- Docsis 3.1 has nothing to do with 16 Docsis 3.0 channels. The Hub 3 and Hitron hub both support up to 24 downstream channels on Docsis 3.0.

  • badhat
  • over 4 years ago

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