Research On The Control And Management Mechanismes In A SIP-based Multi-party Communication System

With the advent of high-speed networking and high-performance computer technologies, distributed multimedia applications are growing rapidly in a variety of fields. As an effective and economic way of transmitting audio and video data, IP-based multimedia conferences are attracting more and more attention from education, research and business. But the lack of control and management mechanismes have influenced the quality and reliability of multimedia conference, and become the bottleneck of its development and deployment.Just surrounding using SIP how to design an IP-based mulitiparty communication system and how to control and manage the conference , we develop the research work about the system architecture and key control mechanismes.The thesis firstly brings a SIP-based tightly-coupled conference framework after analyzing some popular architectures of multiparty communication systems. Then, we give many careful definitions about the interactions among all the conference components. Under this framework, the signaling protocol is SIP and we use RTP/RTCP to transmit media dataflows. The conference server is divided into three functional entities, such as Focus, Mixer, Notification Service. Focus keeps the signaling connection with the conference participants, Mixer treats the media dataflows and Notification Service maintains the conference states and will notify the subscriber when the states change. Meanwhile, for suiting the diversity in the conference participant side, we design two participant groups wich are conference aware participant and conference unaware participant. So this conference archi- tecture has a good interface to be managed and controlled. It also divides the module from treating signal dialogs and treating media dataflows, so it has better scalability.Then, from conference control and management requirements, we design a SIP-based tightly-coupled conference control framework, which includes three key techniques, such as a XCAP and HTTP based technique which is used to modify the conference policy remotely, a XML and CPCP based technique which is used to deposit the conference policy and a technique to carefully define the conference policy elements using XML schema.The conference policy is deposited by hash and this has enhanced the searching efficiency. The friendly operating interface gives users much convenience to configure and manage the conference. So, this framework has realized the requirements betterly.