Tuesday, 4 April 2006

Video on the net is a solved problem, many times over

So why are AT&T and Verizon arguing they need special legal exemptions to build an internet for video? This article is buried in misconceptions so deep, it's hard to know where to start. The basic argument is that in order to provide streaming movies over the internet, they need to build a dedicated connection between content companies and viewers. This is demonstrably false on several levels.

First of all, streaming is pointless - it's applying the TV model to the net, which doesn't fit. The only reason to stream video is if it is live and two-way - an audio or video chat, an interactive game, or a conference with backchannel. In those cases, you can perceive lag between the ends, and you need latency kept low enough - well under a second for the first two, around 10-15 seconds for the third. We can do this over the public internet today, using Skype, iChat AV and QuickTime Broadcaster (among others - I worked on the last two, so you can excuse me mentioning them).

But you don't need low latency for movies. QuickTime has been using plain webservers to serve video for 10 years, very sucessfully. In fact, Netflix have built a very successful movie business over a content delivery network with very high latency, called the US Post Office.

If you do want to deliver movies over the net, and they get popular, your servers and your upload connection may get overloaded (especially if you are an individual user that the telcos have sold an Asymmetric DSL line instead of the fibre to the home they promised us 10 years ago in their last bout of special pleading).

Fortunately there are hosting companies that will cache it for you in their datacenters, like youtube or mac.com. If your movie gets really popular, what helps is distributed caches, closer to the people downloading. Akamai run a service that offers this to companies with lots of money - Apple use it for their high definition trailers.

If you can't afford that, don't worry, we've solved that one too - Bittorrent provides a way for everyone downloading the movie to act as a cache for each other, so you only need a single server seeding them all - Prodigem makes this nice and easy.

So, none of this needs special new 'dedicated pipes', or a VPN. They lost that argument before with ISDN and reserved bandwidth - it was a bad idea then, and it still is, but apparently telcos can't let go of the circuit switched model, even when their circuits have all been replaced by internet protocol.

What makes all these choices for sending video over the net possible is precisely the content-independent end to end principle that the telcos want to throw out so they can privilege their 'dedicated pipes' of packets over ours. Their argument is a tottering inverted pyramid of bullshit, and they need to be called on it publicly.

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