The Design And Implementation Of Multi-party Call For China Unicom

As a result of the development of the information technology companies, different communication ways such as conference call and instant messaging tools, which become increasingly the main communication ways of the company, boost the rapid development of enterprises. However, a poor communication can lead to losses which should not be underestimated. According to some professionals, some SMEs still use telephones with a single voice switching function in their daily work. The use of single, isolated decentralized communication system exists in SMEs in China, which causes the waste of money and laobor for the company. The productivity of employees is thus greatly reduced. The gap between the information communication level of entreprises in China and of those in developed countries is about15years. SMEs are fondamental to the national economic development. They have special requirement on communication systems. The applicable communication systems for them vary. So a communication platform which is esay to manage, inexpensive and reliable will be the future needs of the SMEs. Nowadays, SMEs’needs on communication systems are natural and imposed. The multi-party call conferencing system of China Unicom, known as "light mode" communication system, meets the needs of SMEs in terms of telecommunication, which reduces the information cost of companies and improves the efficiency of communication.Contents of this thesis calls for the realization of China Unicorn’s multi-party system in the project development process, the main hardware design multi-call system, including the overall framework of hardware, system hardware description and security policy; primary and backup systems multiparty calls the system framework includes primary and backup systems, hardware solutions, system security policy; and design ideas to achieve Mina subsystem, system architecture, platform architecture, the design process. Multiparty call in media gateway software to change the gateway, signaling gateway and achieve access gateway, exchange gateway software solutions, hardware, software configuration, system security design; achieve IP transmission, including voice coding, and networking achieve real-time transmission of packet voice implementations, guaranteed quality of service achieved, silence suppression and echo cancellation to achieve, voice jitter implementation. In the communication quality, the study of centralized and distributed mix mix program, the program has been optimized for the mix.At present, the system has reached a stable performance and used officially in China Unicom and becomes one of China Unicorn’s value-added services. The systemreceived good evaluation because of its stability and excellent voice quality in the test of China Unicom before being brought to the market.The system has commercially available in Guangxi Province and Jiangsu Province.