Why does my client stop uploading when the download of a torrent has completed, even though there are leechers?
Maybe your ISP is one of those using a technology called “Sandvine,” which throttles your upload speed once the download has completed. You can read more in articles Traffic Shaping and BitTorrent Protocol Encryption in Wikipedia, in article Avoid Traffic Shaping in Azureuswiki, and in article Comcast Throttles BitTorrent Traffic, Seeding Impossible at TorrentFreak. Use a client that offers protocol encryption such as BitTornado T-0.3.18, Azureus 2.4.0.0 or later, or µTorrent 1.6 or later. Learn how to enable RC4 encryption in Azureus and µTorrent here: How To Encrypt BitTorrent Traffic. Enable the protocol encryption feature in the client and see if that helps. If not, switch to a more BitTorrent-friendly ISP if you can.
