Peer streaming media technology for network data transmission

With the rapid development of computer networks in China, the network AV technology has been widely used. Nowadays people have changed from the traditional entertainment mode (for example: Radio, television) to the network Interactive media entertainment mode, and the streaming media video-on-demand technology satisfies people this kind of interactive entertainment demand. However, due to the restriction of Network Foundation and server capability in China, the large capacity of user service is still a bottleneck restricting the development of streaming media video technology, if the use of peer technology and traditional streaming media technologies can avoid a large number of user Service bottlenecks, which not only reduces the burden of the server, but also improves the utilization of network resources.

It is the use of distributed ideas to classify users ' resources, which is different from the general application layer multicasting, which only participates in the service of the users who are playing. Users in the process of user-to-peer video-on-demand system is also more flexible, users can disconnect the network at any time, and the sharing of resources in the process of bandwidth requirements are not high, which greatly facilitates the user's use, while receiving resources when the user takes a receiving point to multiple senders to transmit data, And according to the bandwidth of the receiving user and the sender to determine the size of the data, improve the utilization of the network.

The composition of peer-to video-on-demand is made up of streaming media server, Index Server, Super User, candidate, and general user, in which the streaming media server is to save the media file and establish the index relation, and the index server is to feedback the index information to the user through the Web server. User management is mainly divided into the user's rights, in which the super-user is responsible for the group members information and members of the management of information transmitted resources, but also responsible for responding to and forwarding the user's query requests, generally a group can only have a superuser.

The design should be based on the resource collection, release, index, play, management as the main direction, in the actual operation of the peer-to-back video-on-demand system should have the following four functions, the first is the release of resources, the network in each node to the network of their own video information to the other nodes Second, the index function, the network users in the retrieval of resources, the system can give the article name and resource information, and provide relevant resource information, to facilitate user choice of resources; again, the resources of the broadcast to a unified format, the site should have the corresponding software download to facilitate user viewing resources; The management function of VOD should take into account the load problem of server and network system, and the system should manage the fragmentation of film resources to ensure the scalability of the system.

The module design of peer-to video-on-demand technology should be based on node, source node and media resource, and realize video-on-demand through node-to-resource storage, source node transfer to resources and media resource release. From the function and design to divide, peer-to video-on-demand technology module design has four parts: the first is the bottom routing, find module design, which is mainly to improve the utilization of the underlying route, and improve the accuracy of the use of resources, in the design according to the resources given by the keywords or words for fast and accurate positioning. We generally use a DHT-based distributed routing lookup algorithm chord improved algorithm to complete this function, but there are some shortcomings in the chord algorithm, so we need to keep a successor node, so that the system more stable, but also to increase the routing table this node to the successor of the RTT value. Only in this way can the routing be faster; Secondly, the design of Semantic search query module, semantic search needs the system has a more abundant resource library, in order to ensure the node to save the resource information in the route, at the same time, according to the Multi-node design concept, The stabiliza-tion between the node and the successor node can exchange known movie information with each other. Thirdly, the design of Load balancer module, with the development of network nodes will be more and more, while the hot resources on-demand pressure will be more and more large, which makes hot resources to form a hot node, if not processing it will cause the temporary failure of resource routing, usually using load balancing method, This can be effective in dealing with such problems. Finally, the film transmitting play module design, in the network film resources in the fragmented streaming transmission, because the multi-node service for a node at the same time, the resource fragmentation tends to reverse the order of the transfer of resources, playback needs to re-order the fragmentation of the resource, so peer-to video-on-demand technology must do this module construction.

The network is a decentralized structure, in the same network, its nodes are both client and server, which has great autonomy in the network application, can avoid the difficulty of frequent access of single resources in the C/s network, and reduce the problem of network paralysis caused by server failure. However, if the use of pure peer-broadcast mode for resource transfer, it is easy to trigger a "broadcast storm", resulting in a more serious network congestion. Considering the above-mentioned situation, the author combines the traditional C/s and peer-to p2p-in the system design, synthesizes the literature consulted, and adopts a centralized mixed structure. As can be seen, the user is divided into a group of points, added a virtual server concept, its existence is dynamic, by each point group of the first client to request data from the server to assume. Requests from other clients in the point group are delivered to the virtual server for processing. If the connection server times out, the virtual server fails, the entire process restarts, and the other clients assume the virtual server.

Peer streaming media technology for network data transmission