Wednesday, September 16, 2009

Ubuntu Internet Software Suite - Transmission

Internet file sharing has become a controversial topic these days in the copyright world. However, networks such as BitTorrent (www.bittorrent.com) have found legitimate use among software companies and other content distributors as a way to offer downloads for larger files without carrying the brunt of the bandwidth use themselves. In fact, Ubuntu distributions themselves are offered as BitTorrent files for quicker downloading.

BitTorrent file transfers work by connecting to a central server and posting information about the file to download, along with your current upload and download speeds. The central server doesn’t transfer the file. It is more of a clearinghouse for information on the file download. Each file is divided into multiple pieces. Individual BitTorrent clients download the individual pieces from other clients who’ve already downloaded them, then advertise which pieces they have to offer to other clients.

This means that clients contact other clients to download the file pieces, rather than downloading directly from the server. This process is called peer-to-peer networking, and it saves bandwidth for the server because clients download directly from each other. While you’re downloading pieces of the file, other BitTorrent clients may be downloading the pieces you have from your client! This is all perfectly harmless because the BitTorrent software restricts the access that clients have to your system.

The key to a BitTorrent download is the .torrent file. The .torrent file contains the file to download and the location of the central server that coordinates the downloads. The standard Ubuntu installation includes the Transmission BitTorrent client. You start it by selecting Applications -> Internet -> Transmission BitTorrent Client.

When you find out that a file is available over BitTorrent, you first download the .torrent file for the item. After you have this file downloaded, follow these steps to get the actual file:
1. Start your BitTorrent client.

2. Select Torrent -> Add. A file browser window appears, allowing you to look for the .torrent file that controls the BitTorrent session.

3. Navigate to and select the .torrent file for the document you want to download, then click OK. The file appears in the Transmission list window, along with some status information. It can take a minute or so for Transmission to fully synchronize with the central server.

4. After the download completes, keep Transmission running in background for a while.
Proper net etiquette dictates that you allow Transmission to continue running so that other BitTorrent clients can retrieve pieces of the download file from you. They have access only to the files you offer in your Transmission session and nothing else on your workstation. The Ratio status for the file indicates how much of the file remote clients have uploaded from you compared to what you’ve downloaded. It’s polite to keep Transmission running at least until you obtain a 1:1 ratio.

5. Stop Transmission and halt the BitTorrent connection by selecting Torrent -> Quit from the menu.

Transmission places the downloaded file in the same folder as the .torrent file.

Both Nautilus and Firefox recognize .torrent files and can automatically start Transmission when you select the .torrent file, either from your local filesystem (in Nautilus) or from a web site link (in Firefox).

Source of Information : Wiley Ubuntu Linux Secrets

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