The greatest achievement of the torrent protocol was the realization that giving up the order in which data is transfered a practical solution multicast problem.
Multicast was always talked about in networking previously, but solutions were found only for niche applications. These tended to have centralized setup requirements and other hurdles, so the internet remained basically entirely unicast.
I still find it incredible that a single source with a slow upload can broadcast to thousands of destinations - who add and remove themselves from the swarm freely, with newcomers automagically caught up - each receiving their full copy of the data mere seconds after the source has finished uploading a single copy.
In retrospect, older multicast ideas such as RFC 1112 (et al) were never going to work. Accomplishing the necessary routing while allowing dynamic group membership would have required adding an incredible amount of complexity switching fabric of the internet.
Another thing is that anyone could spin up a tracker.
Napster etc ran out of central corporate servers. This made them big juicy targets for lawyer bombing. Take out those servers and you take out the whole network.
But with bittorrent the tracker and the search are two separate entities. And over time you got things like DHT and multiple trackers for a single torrent that made it damn hard to knock them out.
Sony has resorted to flooding search sites with fake torrents in an attempt at slowing the spread of the files from the recent attack on their servers...
Multicast was always talked about in networking previously, but solutions were found only for niche applications. These tended to have centralized setup requirements and other hurdles, so the internet remained basically entirely unicast.
I still find it incredible that a single source with a slow upload can broadcast to thousands of destinations - who add and remove themselves from the swarm freely, with newcomers automagically caught up - each receiving their full copy of the data mere seconds after the source has finished uploading a single copy.
In retrospect, older multicast ideas such as RFC 1112 (et al) were never going to work. Accomplishing the necessary routing while allowing dynamic group membership would have required adding an incredible amount of complexity switching fabric of the internet.