PeerCast

PeerCast is an open source streaming media multicast tool introduced in 2006. PeerCast uses peer-to-peer technology to minimize the necessary upload bandwidth for the original multicaster.

The website of PeerCast appears to be abandoned since December 2007. No further updates exist since that date and the source code repository is not available anymore.

Methods

Peercast can be used to implement multicast streaming of audio (Ogg Vorbis, MP3, WMA) and/or video (Ogg Theora, Nullsoft Streaming Video, or WMV), or any other stream of data, over the internet. Peercast uses a distributed bandwidth technique to lighten the load of the broadcaster's upstream bandwidth where each listener/viewer will relay the stream they download to one or more additional listeners. Users may choose how many relays to allow, and if a listener sets their relays to '0', then they will essentially not contribute back to the stream at all.

The benefits of using PeerCast is that it allows any multicasters, particularly small or independent ones, to distribute their streams without need for much bandwidth, saving them costs. It also allows, theoretically, an infinite number of listeners as long as there are enough relays (see below).

Criticism

When a relay is lost, all peers underneath it (might) lose their connection to the stream and must reconnect to another relay, also when reconnecting to another relay, a peer (might) have to accept the point in the stream the new relay is at, potentially causing a skip or repeat in the stream.

Upload bandwidth isn't always reliable, as typical relays are just ordinary listeners. Also, the project is currently in beta and is sometimes unstable.

Peercast does not feature BitTorrent-like swarming; if a point node fails, all others in the tree are mute and dead.

Corporate environments and their security policies might not appreciate the fact that it uses peer-to-peer technology and essentially turns listeners by default into servers.

Since it turns all of the network in a server, distributing content for which you might not have a license could cause legal concerns, depending on the jurisdiction and local legislation the node falls under.

See also

• FreeCast
• Peercasting
• TVUnetworks
• peerCast (app)