Ubuntu中文论坛

huangjiahua 写了：这就是所谓“自私的” p2p 客户端，
好个调整上传/下载比率，
国内大多 BT 软件都是这类做法，甚至还有些是只进不出。


当大家都用标准的 p2p 的时候，少数几个“自私的”可以获得明显的好处，
当大家都用“自私的”p2p 的时候..

huangjiahua 写了：这就是所谓“自私的” p2p 客户端，
好个调整上传/下载比率，
国内大多 BT 软件都是这类做法，甚至还有些是只进不出。


当大家都用标准的 p2p 的时候，少数几个“自私的”可以获得明显的好处，
当大家都用“自私的”p2p 的时候..

Isn't BitTyrant just another leeching client?

No. BitTyrant does not change the amount of data uploaded, just which peers receive that data. Specifically, peers which upload more to you get more of your bandwidth. When all peers use the BitTyrant client as released, performance improves for the entire swarm. The details of this are explained further below. In our paper, we consider situations in which peers use clients which attempt to both maximize performance and conserve upload contribution, but BitTyrant, as released, attempts only to maximize performance.

How is BitTyrant different from existing BitTorrent clients?

BitTorrent differs from existing clients in its selection of which peers to unchoke and send rates to unchoked peers. Suppose your upload capacity is 50 KBps. If you’ve unchoked 5 peers, existing clients will send each peer 10 KBps, independent of the rate each is sending to you. In contrast, BitTyrant will rank all peers by their receive / sent ratios, preferentially unchoking those peers with high ratios. For example, a peer sending data to you at 20 KBps and receiving data from you at 10 KBps will have a ratio of 2, and would be unchoked before unchoking someone uploading at 10 KBps (ratio 1). Further, BitTyrant dynamically adjusts its send rate, giving more data to peers that can and do upload quickly and reducing send rates to others.

Won’t BitTyrant hurt overall BitTorrent performance if everyone uses it?

This is a subtle question and is treated most thoroughly in the paper. The short answer is: maybe. A big difference between BitTyrant and existing BitTorrent clients is that BitTyrant can detect when additional upload contribution is unlikely to improve performance. If a client were truly selfish, it might opt to withhold excess capacity, reducing performance for other users that would have received it. However, our current BitTyrant implementation always contributes excess capacity, even when it might not improve performance. Our goal is to improve performance, not minimize upload contribution.

neomi 写了：

huangjiahua 写了：这就是所谓“自私的” p2p 客户端，
好个调整上传/下载比率，
国内大多 BT 软件都是这类做法，甚至还有些是只进不出。


当大家都用标准的 p2p 的时候，少数几个“自私的”可以获得明显的好处，
当大家都用“自私的”p2p 的时候..

如今国内尽是所谓“自私”客户端，正是你说的“当大家都用“自私的”p2p 的时候..”，试问抱怨的都是谁呢？

标准若是一成不变，那还是不要的好吧。

就在更多客户端探索 bt 出路之时，却仍有人在谈什么“标准”

何况要谈标准，单就选择文件下载这一条就够不标准了（会给上传者增加很多负担），如今还不是连 bittorrent 都支持了

标准要迎合大家的需求，而不是少数几个人的一厢情愿