One of the reasons e.g. BitTorrent works so great is that when you receive a piece from someone, you can trade it for another piece with anyone else in the swarm without that piece. This works since everyone on a torrent (typically) are interested in the same file. With multi-file torrents this assumption is extended to several files as well. In the file-based filesharing world (ed2k, gnutella) the same assumption hold, but but only for one file. And with batchtorrents, this assumption might brake even with torrent; one might only want a few files, (and e.g. using Azureus not even request the other files). Still, two people downloading an episode from same tv-series are quite likely to be interested in the same files, and thus they might benefit from trading. Has any research been done on how these peers with common interests can find each other? Mainly it's about finding the peer with the most coinciding interest. Still, other factors play in, such as the resources available (does the peer lack trading partners, i.e. has bandwidth to spare?) in finding a good match. On the networklevel it might also be good to find a balance between finding the "best" peer and creating a well-connected network (avoiding cliques and bottlenecks). Moreover, as interest's change over time, how should this be handled? (The more coinciding the interests, the longer it should take for them to deviate from each other.) This is question is quite similar to finding a peer with pieces of a file you're interested in (that you don't already have). (The difference being that in the former, you search for _potential_ bearers of the piece.) Here the problem of matching a large number of preferences shows (namely the pieces; there are usually quite a few of them). The same things happens with many (especially small) files. In the search-layer I believe this is usually handled either not at all (random) or in a binary way (complete file vs. only pieces of it), and leaving the details to the strict peer-to-peer chatting. Would there be any point in using more detailed information of finished pieces in the search layer? Would there be any use to use different resolutions (e.g. 10 pieces resolution might be: piece 1-10: none finished, 11-20: all, 21-29: some)? An interesting take on this is the perspective of piece-based networks, where one searches for every piece separately. Here it's even more obvious how much one would benefit from finding people interested in the same file (the same pieces). Yet, introducing things such as patches, it would be pleasing to have a solution that didn't depend on peers wanting the exactly same pieces (defined by the file), but just roughly the same. /Vaste _______________________________________________ p2p-hackers mailing list p2p-hackers@zgp.org http://zgp.org/mailman/listinfo/p2p-hackers _______________________________________________ Here is a web page listing P2P Conferences: http://www.neurogrid.net/twiki/bin/view/Main/PeerToPeerConferences ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> ______________________________________________________________ ICBM: 48.07078, 11.61144 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net [demime 1.01d removed an attachment of type application/pgp-signature]