broadband Engineer engineering internet

Bufferbloat and Virgin Media

Virgin Media Buffering – Bufferbloat spat

Bufferbloat, as most of you will know is the situation in a packet switched network where the packet buffers are so large1 they cause high latency and jitter. Bufferbloat can also reduce the network throughput. This post is all about a guy called Dave Taht and his encounter with Virgin Media buffering issues.

On the face of it the Virgin Media headline speeds are great and one often sees tweets with pictures of speed tests showing near to spec speed results. Virgin’s DOCSIS cable modem tech is far better at meeting theoretical specs than is its various competing DSL technologies. I do however occasionally hear anecdotally about Virgin Media buffering problems with their broadband connections.

This blog post describing the Virgin Media buffering problem due to bufferbloat is a bit of an eye opener.

Dave Taht knows what he is talking about when it comes to network performance and pitched in on a Virgin Media forum to complain about why they weren’t doing anything about their buffering problem. Dave ascribed this Virgin Media buffering problem to bufferbloat. Dave is an expert on bufferbloat – check out his website.

In the forum post Dave offered advice on what to do to sort the buffering problem – there are a number of well established fixes.

Virgin not only deleted his post but blacklisted his IP address. This is quite counter productive. It seems to me it would have made much more sense to fix the issue than throw their toys out of the pram. The former course would have generated lots of good PR. The latter the opposite. Witness my own particular post.

The decision to delete Dave’s post was probably take by a low level supervisory person. If a member of the senior management team had been involved one would like to think they would have taken a different approach. It doesn’t matter now. It is interesting to understand that these consumer service businesses are all played out a 60 thousand feet. It’s a game of throwing enough money at specific macro level functions of the business – usually marketing.

Spending a lot on advertising how great you are goes a long way towards making a sale. Most people are sufficiently disinterested in the detail of how their broadband works to note buffering as an issue. It’s only when something gets really bad that people up sticks and go elsewhere.

I don’t know where buffering is at in the Virgin Media list of priorities – something quite possibly driven by the marketing department. It is a shame that they don’t seem to be wanting to fix it though.

1 The fertile imagination will now see a packet buffer large enough to store a whole movie – you will never get to see it:)

Footnote from Dave Taht this evening: (I take no credit for the result 🙂

Thank you. I got my access restored this morning and updated my blog
post, and will put out more information later today on the mailing
lists I spammed later today – BUT! I have no problem continuing
holding the entire industy’s feet to fire for a while, so I don’t
suggest changing your piece on that front.

However, it would benefit from the addition of an embedded link to
this talk at uknof – which is the shortest talk I gave EVER on this
issue, and thoroughly describes the revolution we could make,
together, if we work at it:

(I don’t remember how to embed videos in html anymore!)

… after which I’d had such hope from the follow-on meeting at virgin
as to walk out walking on air. 2 years ago. 🙁

I certainly would like all ISPs to do a little testing of openwrt +
sqm-scripts with fq_codel (barrier breaker has all the fixes that work
on cablemodems, and has a nice gui and is stable. Chaos calmer has all
the DSL fixes, but is not quite stable and takes some work to use –
but it works on currently shipped things like the wndr4300. )

and publish appropriate settings. It is hard for users to get the
measurements right.

All the home router products that just shipped, got their shaping
algorithms terribly, terribly, wrong and missed DSL and PPPOe
compensation entirely. Sigh.

Trefor Davies

By Trefor Davies

Liver of life, father of four, CTO of, writer, poet,

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