H.320 Video Conference Encryption System And Its Test Terminal Development,

Videoconference being a new teleservice which develops rapidly in recent years has been applied to many industries, such as enterprises, governments, etc. The function of videoconferencing system combines video transmission, audio transmission and data transmission. It is very convenient to implement many multimedia data teleservices, for example, documents sharing and electronics whiteboards between multiple locations when holding a meeting on videoconferencing system. Videoconference has brought renovation to our mode of communication, saved much time and cost, and improved efficiency. Indications suggest that Videoconference will some day become the primary mode of distance communication.Videoconferencing system, which integrates the technology of communication networks, computer science and signal processing, is one important part of multimedia technology. The technology of Videoconference has become more and more mature after many years' development. Many recommendations on video and audio transmission have been publicized, among which H.32X recommendation series established by ITU-T have been applied far and wide. ITU-T H.320 recommendation is used most widely which describes the videoconferencing system over ISDN.In the practice, the information transmitted in the Videoconferencing system often involves much privacy, such as enterprises' business secret, governments' confidential information and so on. It will result in harmful impacts if the security of Videoconferencing system is neglected. To encrypt the multimedia information transmitted over the network is an effective measure to ensure the communication security. In this paper a type of videoconferencing encryption system is put forward, which is applicable for the Videoconference according to ITU-T H.320 recommendation. The encryption system supplies powerful security guarantee by not only encryption and decryption mechanisms, but also authentication. The videoconferencing encryption system is in accordance with H.320 recommendation, thus it's important to lucubrate the recommendations, especially H.221 recommendation describing the frame structure of videoconferencing channel.The main content of this graduate design is to design and implement the testing terminal for videoconferencing encryption system. The testing terminal is applied to testing of the videoconferencing encryption system, and of the H.320videoconferencing terminals. Simultaneously, partial electrocircuit in this plan serve the turn of the encryption system optimization, as is of great practical value. The primary function of the testing terminal includes producing serial digital signals according with frame structure defined in H.221 recommendation, receiving signals from videoconferencing encryptor or videoconferencing terminal and picking up the frame alignment signal to examine the synchronization, and providing selection among multiple network interfaces and multiple communication velocity. A scenario of implementation of the testing terminal comprising in-system programmable digital design and software control is introduced in this paper.