Peercasting is a method of

multicast In computer networking, multicast is a type of group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast differs from ph ...

ing

streams A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

, usually audio and/or video, to the

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

via

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network, forming a peer-to-peer network of Node ...

technology. It can be used for commercial, independent, and amateur multicasts. Unlike traditional

IP multicast IP multicast is a method of sending Internet Protocol (IP) datagrams to a group of interested receivers in a single transmission. It is the IP-specific form of multicast and is used for streaming media and other network applications. It uses speci ...

, peercasting can facilitate on-demand content delivery.

Operation

Peercasting usually works by having peers automatically relay a stream to other peers. The P2P

overlay network An overlay network is a logical computer network that is protocol layering, layered on top of a physical network. The concept of overlay networking is distinct from the traditional model of OSI model, OSI layered networks, and almost always assum ...

helps peers find a relay for a specified stream to connect to. This method suffers from poor quality of service during times when relays disconnect or peers need to switch to a different relay, referred to as "churn". Another solution used is minute swarming, wherein a live stream is broken up into minute length files that are swarmed via P2P software such as

BitTorrent BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...

or Dijjer. However, this suffers from excessive overhead for the formation of a new swarm every minute. A new technique is to stripe a live stream into multiple substreams, akin to

RAID RAID (; redundant array of inexpensive disks or redundant array of independent disks) is a data storage virtualization technology that combines multiple physical Computer data storage, data storage components into one or more logical units for th ...

striping.

Forward error correction In computing, telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels. The centra ...

and timing information is applied to these substreams such that the original stream can be reformed using at least all but one of the substreams (

fountain code In coding theory, fountain codes (also known as rateless erasure codes) are a class of erasure codes with the property that a potentially limitless sequence of encoding symbols can be generated from a given set of source symbols such that the orig ...

s are an efficient way to make and combine the substreams). In turn, these streams are relayed using the first method. Another solution is to permit clients to connect to a new relay and resume streaming from where they left off by their old relay. Relays would retain a back buffer to permit clients to resume streaming from anywhere within the range of said buffer. This would essentially be an extension to the

Icecast Icecast is a streaming media project released as free software maintained by the Xiph.Org Foundation. It also refers specifically to the Server (computing), server program which is part of the project. Icecast was created in December 1998/Janua ...

protocol.

Software used for peercasting

Free and open source software

Alluvium (peercasting) Alluvium is open source peercasting software developed by thFoundation for Decentralization Research first released in 2003. It comprises three components, ''Core'', ''Media Player'', and ''Server''. Alluvium allows video and audio programming to b ...

Tribler Tribler is an open source decentralized BitTorrent client which allows anonymous peer-to-peer by default. Tribler is based on the BitTorrent protocol and uses an overlay network for content searching. Due to this overlay network, Tribler do ...

PULSE In medicine, the pulse refers to the rhythmic pulsations (expansion and contraction) of an artery in response to the cardiac cycle (heartbeat). The pulse may be felt ( palpated) in any place that allows an artery to be compressed near the surfac ...

Proprietary

Ace Stream Ace Stream is a peer-to-peer multimedia streaming protocol, built using BitTorrent technology. Ace Stream has been recognized by sources as a potential method for broadcasting and viewing bootlegged live video streams. The protocol functions as ...

PPStream PPS.tv (PPStream) is a Chinese peer-to-peer streaming video network software. Since the target users are on the Chinese mainland, there is no official English version, and the vast majority of channels are from East Asia, mostly Mainland China, ...

Rawflow {{short description, Streaming technology company RawFlow was a provider of live p2p streaming technology that enables internet broadcasting of audio and video. The company's technology is similar to Abacast and Octoshape. Rawflow was incorporat ...

Red Swoosh Red Swoosh was a peer-to-peer file sharing company founded by Travis Kalanick and Michael Todd in 2001. It was acquired by Akamai in 2007 for $19 million. History Red Swoosh was founded by Travis Kalanick and Michael Todd in 2001. The company ...

Veoh Veoh () was an American video-sharing website, created in September 2005 by Dmitry Shapiro and Ted Dunning. Originally launched as a virtual television network application, Veoh re-established itself as a video-sharing website in March 2006. D ...

(defunct)

References

{{File sharing Digital audio File sharing Technology neologisms Peer-to-peer computing

Operation

Software used for peercasting

Free and open source software

Proprietary

See also

References