Research And Application Of RTP Based On QoS Multicast

Multicast transport of real-time multimedia data is the trend of Internetdevelopment. However, the current best-effort Internet does not offer any QoSGuarantees for real-time data. In addition, the heterogeneity of the Internetmakes it difficult to efficiently support real-time data multicast while providingflexible service to meet a wide range of QoS required by users. Thus, how totransport real-time data with high quality is a currently important research issue.At first, the paper introduces the current status and development trend ofQos Multicast Routing, describes the RTP/RTCP protocol and its characteristicin detail. On this basis, this paper presents a way, which adjust the transmissionrate dynamically to avoid the congestion and packet loss, and as well as a waywhich adjust the buffer size dynamically to reduce the time delay and jitter.They use feedback information provided by RTCP to adjust the QoS parametersand then make real-time data transmission adapting to the fluctuations innetwork bandwidth dynamically. So the optimal quality of service is achieved.At the end of the paper, a video system based on Qos multicast routing isdeveloped. The experimental results show that the mechanism can achieve thefriendly behavior of TCP, and at the same time, guarantee the quality of the video varies smoothly as the bandwidth of the network fluctuated.