Virgin Media are today altering their “traffic management policy” in an effort to manage high downloaders volume users.

Varying by your selected broadband tariff your speeds will be monitored, and once a certain level is reached within a given hour, you will be throttled back to a reduced speed. You’ll still have service, but with up to 40% of your download speed being removed, and 75% or your upload speed, it could hit you hard.

While I agree high volume downloaders need to be managed so they don’t ruin the availability and capacity for anyone else, the limits Virgin Media have imposed are a little worrying.

Virgin Media Introducing Bandwidth Throttling - Netflix HD Users Will Be Hit

Take the L30 package that I’m on, a mid-range tariff that provides speeds of up to 30Mbps down and up to 2Mbps up (don’t forget many users never actually see these speeds). At peak times in the evenings (4pm to 11pm) and practically the whole day at the weekend (11am to 11pm) if you exceed 2.7GB in an hour or 3.5GB in 2 hours you will be throttled to 30% and 40% capacity respectively.

Sounds a lot? Who would download 2.75Gb in an hour except large downloaders right?

Well unfortunately, watching Netflix can land you right in this category, and lead to your reduced level of service. Netflix bandwidth guidelines (available here) show that streaming HD video in best quality will mean you’re downloading 2.8GB per hour – conveniently just over the Virgin Media limit.

Lovefilm say that 2 hours of their HD streaming will use “about 10 Gigabytes of data” – 5GB per hour which is even worse. iPlayer HD on the other hand is estimated to only use about 1.1GB / hour so might be the service you have to resort to until after 11pm.

When you’re running at 30% capacity you might just about still be able to stream and finish the rest of your movie (if you watch another you’ll likely tip over the 2 hours and be reduced the further 10%) but I have friends on Virgin Media who experience buffering just watching Netflix normally, at 100% of the capacity they signed up, and pay, for. Losing 30% might well be too much for them!

Virgin Media Introducing Bandwidth Throttling - Netflix HD Users Will Be Hit - Twitter ResponseI appreciate the need to maintain network quality for all customers, but I don’t think grouping simple streaming television users in with “heavy downloaders” and treating them to the same restrictions is the answer.

Pointing this out to Virgin Media on Twitter led them to concede “Looking at that – I can appreciate your point most certainly. Hopefully as our network improves the policy relaxes” so maybe there is some room for this to be sorted before it hits too many people too hard.