Bit Torrent for GIS described:
0) Publisher needs to a)run a tracker service and b)provide a seeding
copy of the file citated.
Tracker service needs to be on a server. Open source
Azureus can be used to manage the tracker.
1) User obtains a xxx.torrent file to download the matching xxx file
Inside the .torrent file are metadata for the
file to be downloaded:
e.g. file name, address of a
tracker, hash as check sum , etc
The .torrent file is small, typically less
than 1meg.
A browser (such as MS Internet Explorer, or
Mozilla) can be used to download the .torrent file
2) User then activates a client bit torrent program that uses the
.torrent file to start the download.
Open source Azureus is one such client
program. The client carries on the download and allows sharing of its
downloaded portions for others to also
download. There is load-leveling on bandwidth usage as
high demand means high availability.
3) Difference from other file-sharing protocols are:
3a) Search by browser to obtain the .torrent file; effective for GIS
type files utilizing mapping aids.
3b) Remove the citation from the tracker and the torrent is no longer
accessible.
4) Control form is centralized management and de-centralized
distribution.
5) Within a firewall, an allowed bit torrent server can be explicitly
defined. This will allow targeted file serving without opening the
firewall for all torrent tpye packets.
rev 2006 apr 19 (j_torrent.html)