On Wed, Apr 16, 2008 at 9:38 AM, Anthony wikimail@inbox.org wrote:
On Wed, Apr 16, 2008 at 9:35 AM, Simetrical Simetrical+wikilist@gmail.com wrote:
Yes, I'm aware of the *theory*: BitTorrent hashes each chunk and automatically verifies them. But I'm curious to know if that makes a difference in *practice*, since someone mentioned it as a significant advantage of BitTorrent over HTTP.
TCP checksums each packet, so I'm not even sure bittorrent is more reliable in theory.
In theory:
1) BitTorrent uses SHA1, TCP uses CRC32 (IIRC). CRC32 is more error-prone.
2) TCP only insures that the packet was transmitted correctly, not that the packet was correct in the first place. If, for instance, the torrent is published, some server or other stores a chunk to disk, and the chunk acquires an error on disk, BitTorrent will catch the error when someone requests the chunk. TCP will not, because the error was not on the network.
3) ???