NNSquad - Network Neutrality Squad
[ NNSquad ] Re: define: "service providers have to manage their networks somehow, especially during peak times."
At 12:59 PM 3/27/2008, Robb Topolski wrote:
Recently, George Ou tried to repaint BitTorrent as a non-neutral application because it "exploits" long-standing congestion controls by using multiple connections to download a single file[1].
George is correct. BitTorrent exploits the fact that congestion control in TCP/IP was implemented (a) as an afterthought; (b) only at the "ends," which cannot detect the location of a bottleneck upstream; and (c) ignoring the fact that any such implementation can be gamed by starting large numbers of flows. Worst of all, it only reacts to failure. (Yes, a dropped packet does constitute a failure -- especially in today's Internet, where only a few of them mean a dropped VoIP call.)
I hold that his reasoning is errant because any benefit exists only while the TCP connections are recovering from the congestion.
By using multiple streams, BitTorrent creates CONSTANT congestion and thus constantly benefits at the expense of other applications.
Congestion control responses to a dropped packet are an attempt to keep an ailing network alive and communicating. No system runs well when demand outstrips its capacity for extended periods.
You are blaming the victim. If one creates virtually unbounded demand via P2P, one should not be surprised that demand exceeds capacity. Witness the Japanese experience, as documented at
http://www.brettglass.com/ITIF/pg6.html
When Japanese ISPs added capacity, P2P occupied virtually all of it and in fact saturated the network more completely than before.
--Brett Glass