In these years, the needs of bandwidth extraordinary grow for IT development that makes data transport become highly huge than before, so apply IP multicast technology is an important way for optimizing bandwidth.

• 近年来,随着信息技术的迅猛发展,网络应用大量增加,使得原来已经存在的、庞大的数据传输量成倍增长,而优化带宽可满足数据传输量增长的需要,IP组播技术则是优化带宽的重要手段。