Friday, December 04, 2009

Bandwidth Hogging

There are several discussions going on around the web about bandwidth hogging started by a post from Benoit Felten in the fiberevolution blog. I wrote about this issue last month in my post on net neutrality. The basic problem is that when the internet becomes congested the person who has created the most connections wins. Congestion can happen anywhere from your local head end through to a backbone and the backbone interconnects. Felten claims that there is no problem, and given the data, he is willing to do the data crunching to prove it, while others disagree.

The problem is a classic Tragedy of the Commons. There is a shared resource, the internet, and some people use more of it than others. That is fine provided that they do not interfere with each other and there is enough resource to go around. As I explained, the problem is that when there are not enough resources to go around, the people who win are the people who create a large number of connections, and these tend to be the people who use the most bandwidth. The point of a torrent client creating a large number of connections is to ensure that that the client gets its "share" of the net whether there is congestion or not. The only viable response is for everyone else to create large numbers of connections to do whatever they want to do, be it download a web page or make a internet phone call. This is undesirable because it can only lead to more congestion and less efficient use of the shared resource.

There are two parts to a solution. Firstly, the internet service providers have to keep adding more equipment to reduce congestion as internet usage grows. Everything would be fine if there were no congestion. Secondly, we need better algorithms to manage congestion. Penalizing people for using the bandwidth they were sold is not the answer, particularly when that is not the real problem. I have suggested that we should look towards limiting connections. Another thought is to kill the connections of the users with the largest numbers of connections to reduce congestion. Again, I am sure that this will have some unintended consequences.

The real problem is that unless we can all agree to be good internet citizens and get along, the forces against Net Neutrality may win. Then large companies with deeply vested interests will get to decide who has priority. The recently announced merger of Comcast, a large Internet Service Provider and NBC, a large content provider is exactly the sort of thing that we need to be wary of.

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