Frequently Asked Questions

µTorrent 3.0

How does streaming work?

Normally, µTorrent downloads pieces of a file in random order. For example, it may download a piece from the first 10 seconds of a file and then another from the middle of the file and so on. While this is the most efficient way to download files, it doesn't allow for continuous playback of files from start-to-finish until the entire file is completed.

When a user invokes streaming for a file, uTorrent gets the files in order from start to finish. This allows a user to actually play the file while it's still downloading.

If downloading pieces in random order is most efficient, doesn't streaming negatively affect the torrent ecosystem?

If everyone streamed every file at the same time, the ecosystem would be negatively affected. That’s why we’ve put in safeguards to protect the ecosystem such as disallowing streaming when there aren’t enough seeders for a file, and preventing users from streaming more than a single file at a time. With these protections, we’ve tested and found no negative effect on the ecosystem. This is a property we’ll continue to monitor and adjust for as streaming becomes more widely used.

How private is commenting?

Comments propagate through the swarm and offer no more or less privacy to the user than does participating in a swarm in the first place, which he does when downloading a torrent file.

How exactly does commenting work?

µT 3.0 adds an extension message for distributing comments within the swarm. All clients that support this extension message store all comments they have seen, per torrent.

When peer A joins a swarm, it will send a request for comments to peers that support this message, say peer B. If peer A already has some comments, it passes along a bloom-filter representing the set of all those comments. When peer B responds, it will not send comments that are already present in the bloom filter. This prevents duplicate comments.

Peers re-request for comments every 20 minutes, from all peers. This is how comments are propagated within the swarm. If a very significant portion of the peers in the swarm do not support the comment extension message, comments might have a harder time being propagated to all peers supporting the extension.

Comments are never sent to swarms to which they don't belong. Comments are stored in the resume file for a torrent, which helps keep comments alive across sessions.