Research And Implementation Of Congestion Control Method For Active Network Reliable Multicast

With the continuous development of internet network technology and great expanding of its applications scale, many new services come to the fore, such as webcast, distance telemedicine and so on. However, the conduct of these services requires the network support multicast technology. Multicast technology is relative to the traditional unicast technology, which is used to achieve the purpose of data transmission one-to-many or many-to-many from source to end. This technique only needs to send the data once to each of the receiver which really needs the data, it does not produce redundant data transmission. Thereby it makes full use of network resources. In the traditional internet architecture, multicast technology achieves mainly through IP multicast technology, however, there is only one protocol to support it, that is UDP, which never guarantees reliable multicast data transmission. In order to ensure the reliability of IP multicast, we must get the support of reliable multicast technology. Although reliable multicast technology solves the problem of reliable multicast transmission, but due to the enormous number of recipients of reliable multicast network, it finally results in a more serious congestion control problem.Reliable multicast congestion control method can be divided into window-based algorithm and rate-based algorithm, also it can be divided into single-rate algorithm and the multi-rate algorithm. The implementation of these algorithms, more and more urgently demands the network has a flexible services, but the traditional network lacks the appropriate mechanisms, so, it needs a new network environment to meet service needs. Active network environment is a new type of network environment, it brings a flexible network through the powerful computing capability of intermediate nodes. It provides a flexible implementation of the environment for a variety of congestion control algorithm, which makes reliable multicast congestion control problem has a new solution idea. This paper studies deeply on the reliable multicast congestion control methods in the active network environment, and hopes to be able to propose a more reasonable approach, so as to improve and perfect the traditional reliable multicast congestion control methods.This paper firstly describes the reliable multicast technology, and analyzes the principle and implementation of reliable multicast technology, then makes in-depth study of reliable multicast congestion on the traditional network control method as well as in active network environment control method, and presents a model based on binary non-cumulative layering algorithm BMN. This algorithm can obtain a more finer granularity than the traditional cumulative hierarchical algorithm, and it can make more fully use of network bandwidth. On this basis, this paper designs an active networks reliable multicast congestion control method based on BMN algorithm BMN-ANCC, it applies BMN algorithm to the process of active networks reliable multicast congestion control. Finally it adopts simulation software NS2 to simulate BMN-ANCC, it verifies the scalability and TCP friendliness of BMN-ANCC, and achieves the basic evaluation index of a reliable multicast congestion control method.