在IP视频会议系统中，音频流需要保持其连续性(媒体内同步)，而视频流的变化应与音频信息保持一致(媒体间同步)。由于网络状态的变化给传输带来延迟抖动，因此接收方要如实地播放，就必须进行同步控制，以恢复数据之间的时间关系。为此探讨了在MCU集中管理模式下的视频会议系统中，音视频同步控制的问题，并结合RTP／RTCP协议给出具体可行的解决方案。

Audio stream needs to keep continuous, and video stream movement should be consistent with audio stream in Video Conference System over IP. Varieties of net conditions bring transmission delay jitter. The receiver must take synchronization control to resume time relation of stream before playing them according to the facts. This paper discusses the synchronization control in convergence MCU mode and present some specific and operatable solutions.