Application layer multicast service realizing method, terminal and system thereof

Abstract

The invention relates to an application layer multicast service realizing method, a terminal and a system thereof. The method comprises the steps that: a node is added in a multicast network; father node information, a brother node table, a father and brother node table and a child node table are established locally; the node information of a father node is collected for updating the local father node information; the child node table of the father node is obtained for updating the local brother node table; and the brother node table of the father node is obtained for updating the local father and brother node table. The terminal comprises a father node information storage module, a brother node table storage module, a father and brother node table storage module, a child node table storage module and an information updating module respectively connected with the modules. The system comprises a root node and adopts a plurality of realizing terminals as leaf nodes. The invention can avoid the influence of frequent change of the multicast network, promote the reliability and extendibility of the multicast network, link brother nodes for data transmission, fully utilize exported broadband and improve data transmission efficiency.

Description

technical field [0001] The present invention relates to a method, a terminal and a system for implementing an application layer multicast service, in particular to a method for implementing an application layer multicast service that distributes data in a multicast network based on P2P technology, and a terminal and a system for implementing the multicast method . Background technique [0002] In the Internet, the distribution and transmission of data is one of the most commonly used functions, especially with the development of multimedia technology and Internet technology, the distribution of streaming media data such as video and audio with high real-time requirements has occupied most of the network. bandwidth. Therefore, how to improve the distribution efficiency and reliability of streaming media data has become an issue of great concern at present. [0003] Existing multimedia data distribution methods mainly include the following categories: 1. Traditional client / s...

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Problems solved by technology

[0006] 1. "End System Multicast" scheme: Firstly, the multicast members, that is, the customer nodes are organized into a mesh and connected, and each node maintains a list of all multicast members to reduce the impact on other nodes when a node joins and exits, so as to Improve the reliability of the multicast tree; construct a multicast tree on the Internet with the node where each data source is located as the root node, so that the performance of each node where each data source is located can be optimized; but the disadvantage of this solution is that the system overhead is relatively large , which reduces the scalability of the system and is only suitable for small-scale multicast networks;

[0007] 2. "ALMI" scheme: maintain a minimum multicast tree among multicast members. This scheme can reduce system maintenance overhead, but the transmission overhead distributed from each data source cannot be optimized separately. The maintenance overhead of the minimum multicast tree It also limits the size of the multicast network;

[0009] The defect of the above-mentioned application layer multicast technology is: since most of the nodes are common user hosts, the performance difference of the nodes and the random joining and exiting seriously affect the entire group The stability of the broadcast tree, the congestion of the upper layer application layer link will directly affect the lower layer link; the egress bandwidth of the leaf nodes, which accounts for a large proportion of the system, has not been effectively utilized, and there is a situation of free rides, which hinders the fairness of the entire system. Specifically in the "NICE" mode, as a representative node, the in-degree is "1" but the out-degree is greater than "1". When the representative node downloads a data packet, it needs to transmit the data packet to multiple other nodes. For For the hosts of ordinary users, it hinders fairness and is difficult to promote; taking the "NICE" model as an example, many nodes at the bottom layer can only obtain data streams from one representative node, so the data distribution efficiency is low; in addition, some nodes' The egress bandwidth is unstable or relatively small, which is not enough to provide complete data flow for other nodes, and the egress bandwidth of these nodes will also be wasted

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