Advances in technology evolution of Peer-to-peer and IPTV 2

Author: Houzhiang//><!--Source: Communication World Network release time: 2008-2-1 9:28:31//--><!

There are two methods to distribute the content of broadcast film and TV materials: One way is to download, download and then watch, this method is now called podcast (Podcast), the other is to use streaming media to watch while downloading. Peer-to-peer technology supports both of these approaches.

Peer-to-peer sharing downloads are more familiar to everyone. At present, the commonly used Peer-to-peer software BT belongs to the third generation of mixed-type organization-free network. Every day tens of millions of netizens use BT software to download the entire film, MP3 and large software, and its data flow has accounted for more than 70% of the total Internet data traffic worldwide. Similar in China, the majority of broadband users are peer-to-peer application of traffic. Copyright problem is the main problem that puzzles Peer-to-peer download development, now some of the podcast websites with legal copyright have begun to develop healthily.

Peer-to-peer Streaming media is developed in recent years, currently in China has developed very well, with more than 10 Web sites using self-developed software to provide peer-to-peer Internet video services, registered users up to 2.5 million households.

The development of 3.P2P streaming media broadcasting technology

Using Peer-to-peer technology to achieve large-scale streaming media on demand and live Broadcast system webcast appeared in 1998. Webcast uses a binary multicast tree to transmit and share real-time multimedia data between users. Since then, because streaming media direct service is relatively simple, the first rapid development. A prototype--ESM system of the first Peer-to-peer video live broadcast system was presented in 2000, which uses user network structure interconnection to construct the optimal media data multicast tree to propagate real-time multimedia content among users. Due to algorithm limitations, this system can only be extended to thousands of people at the same time online, but has marked a peer-to-peer streaming media live system into the system development period.

Since then, a variety of prototype systems, highly scalable application layer multicast protocols have emerged. Typical systems include the Standford University's Peercast system and the German P2pradio system, which provide audio broadcasts, both of which use open source code. The Application Layer multicast protocol has Microsoft's Coopnet/splitstream agreement, Cisco's overcast agreement, the Nice Agreement at the University of Maryland, the gossip agreement of the University of Berkeley. Although these systems and protocols can not be practical, but for Peer-to-peer streaming live media has laid a solid theoretical foundation.

During the Euro May 2004, the CoolStreaming prototype system developed by Dr. Zhang Xinghi of the Hong Kong University of Science and Technology was successfully tested on the Planetlab Web site. The system uses the GOOSIP protocol to propagate control signaling between users, using a multicast-like multi-point multicast protocol to transfer media packets between users. CoolStreaming system is the first real application of high scalability and high reliability Network Multicast protocol in the Peer-to-peer streaming system, marking the Peer-to-peer broadcast technology into the quasi commercial operation stage. Inspired by the success of CoolStreaming, China streaming media technology and business development rapidly, unique in the world, at present, China has more than 10 websites using their development software to provide peer-to-peer streaming live media business. The most users are the Synacast system adopted by PPLive network. The core of Synacast system is a complete set of online video transmission and operation support business platform. This platform can easily complete the program collection, publishing, certification, statistical analysis and other functions.

Because the Peer-to-peer technology is used to distribute streaming media content, the Synacast system has lower requirements on the server side. Typically, each source distribution service consumes only about 5% CPU load, Mb of memory and network bandwidth of up to MB. Take PPLive network as an example, the site originally used a traditional Windows Media server, a MB/s server in a unicast way to provide a live broadcast of the program, up to the support of 200~300 users concurrent access; When the Synacast technology is used, a MB/MB s access to the Internet's ordinary PC server can also provide 5~10 road video broadcast live, each program can support millions of users at the same time viewing.

    at present, the main performance of Peer-to-peer streaming media Live is as follows: The rate of the broadcast TV program is generally 3~500 kb/s, some channels have begun to provide kb/s rate, more than the quality of the VCD screen; s~1 Min around the completion of data buffering, and began to play, can provide users with stable, clear television programs, the general will not appear to stop the problem of playback, with the intranet through the function, so as to ensure the use of intranet users; Use 5~10 MB/s server export bandwidth to support millions number of users simultaneously online; Billing platform.