Study On The Multistage Forwarding Mechanism Based On Video Networked Monitoring Platform

As the expressway in China has gradually interconnected, the Video Monitoring Systems in different road-sections which worked separately can't meet the demand of mamagement. The current Video Monitoring System is changing from separate-control mode to a network-control one. Therefore, It is an urgent task to estabilish provincial regional expressway Video Monitoring System by making full use of the original ones.Taking the practical demands of expressway system of Jiang Su province as a background, a multistage forwarding mechanism which based on Video Networked Monitoring Platform (VNMP) and paralled with the administrative management is studied and designed in this paper so as to implement the design idea of distribution management and central control, and also to realize the sharing of the different domains'video resource.First, according to the business and functional requirement, the multistage hierarchy division of VNMP and the cross-domain monitoring model is generally introduced in the paper. Then the interstage forwarding scheme of media stream and control flow is designed, including interstage stream miedia forwarding mode, interstage control strategy and the design of data format such as forwarding table, forwarding protocol and so on. It emphatically analyzes the flow of forwarding and the scheme of real-time control in the paper when multiuser concurrent access to multistage and multidomain,combining with the management thought of system's authority, resource and link. The corresponding strategy aiming at the forwarding abnormal and the real-time problem is also put forward. Meanwhile, the theory analysis and practice design of the technologies referred to in the paper is given. These technologies include streaming media, video compression, multicasting and NAT traversal, etc.At last, the development of VNMP's multistage forwarding which based on the mechanism above was successfully achieved. Meanwhile, its function and property including the accuracy, the efficiency, and the reliability has been fully tested based on building a test environment, and has been proved by running in the practice project environment on the expressway network of Jiang Su province. The result showed that, the system had a better capability to realize the expected target of multistage forwarding, satisfied the need of design and solved the key problem of streaming media's calling and transmission when multiuser concurrent access to multistage and multidomain. It can be extended to Public Security, Fire Protection and each other fields. It has a bright application prospect and research significance.