Bittorrent: Where do IP addresses come into picture?

Question

I am reading about the Bittorrent protocol and couldn't find this mentioned on the Wiki page. I could understand the role of trackers and publishers but from a practical perspective, I tried contacting a tracker to give me some information and it gave me the following:

7%00%00%04%82%91%F3%CA%D5%92%08%C8%7C%B0%AE%1E4%2B%E4C:0:1

Now, the long string in the beginning is perhaps the info hash. As a next step, I did this:

http://tracker.sometracker.com/announce?info_hash=7%00%00%04%82%91%F3%CA%D5%92%08%C8%7C%B0%AE%1E4%2B%E4C

It gave me back a torrent file. So far so good. The torrent file contained this:

d8:completei0e10:downloadedi0e10:incompletei2e8:intervali1931e12:min intervali965e5:peers12:U���ٿ��ӣǣ^@^@e

I went to this site: http://en.wikipedia.org/wiki/Torrent_file but couldn't find any description (or perhaps missed it). Now, if I am the client and I get this file, where do I get the list of IP addresses that have the file?

Answer 1

Have a look here:

http://www.bittorrent.org/beps/bep_0003.html