组播（Multicast）是将信息只发送一次,在网中申请过组播地址的用户均可收到,带宽利用率高,用户数多。将组播机制融入MCU,可极大地增加多媒体交互系统的用户数,降低带宽占用,使MCU的综合处理能力得到提高。-Multicast (Multicast) the information is sent only once, apply for the multicast address users can receive high bandwidth utilization, the number of users in the network. Multicast mechanism into the MCU, can greatly increase the number of users of multimedia interactive systems, to reduce bandwidth consumption, improved comprehensive processing capabilities of the MCU.