Video courses have become a significant component of modern education. However, the increasing demand for live streaming video courses places considerable strain on the service capabilities of campus networks. The challenges associated with live streaming course videos in campus network environments exhibit distinct spatial distribution characteristics. The audience for specific video courses may be highly concentrated in certain areas, leading to a large number of users attempting to access the same live stream simultaneously. Utilizing a Content Delivery Network (CDN) to distribute videos in these campus scenarios creates substantial unicast pressure on edge CDN servers. This paper proposes a two-layer dynamic partitioning Recursive Bit String (RBS) virtual domain network layer multicast architecture specifically designed for large-scale, geographically dense multicast scenarios within campus networks. This approach reduces redundant multicast messages by approximately 10-30\% compared to the two-layer fixed partitioning method. Additionally, it establishes multicast source authentication capabilities based on Source Address Validation Improvement (SAVI) and facilitates secure multicast group key exchange using a concise exchange protocol within the WebRTC framework. In the next-generation data plane of programmable software-defined networks, the RBS stateless multicast technology can be integrated with the unique characteristics of large-scale, geographically dense campus network scenarios to dynamically and efficiently extend multicast coverage to every dormitory.

翻译：视频课程已成为现代教育的重要组成部分。然而，日益增长的直播视频课程需求对校园网络的服务能力造成了巨大压力。校园网络环境中直播课程视频所面临的挑战呈现出显著的空间分布特征。特定视频课程的观众可能高度集中在某些区域，导致大量用户同时尝试访问同一直播流。在此类校园场景中使用内容分发网络（CDN）分发视频，会给边缘CDN服务器带来巨大的单播压力。本文提出一种专为校园网络内大规模、地理密集组播场景设计的两层动态分区递归比特串（RBS）虚拟域网络层组播架构。与两层固定分区方法相比，该方法可将冗余组播消息减少约10-30%。此外，该方案基于源地址验证改进（SAVI）建立了组播源认证能力，并利用WebRTC框架内的简洁交换协议实现了安全的组播群组密钥交换。在可编程软件定义网络的下一代数据平面中，RBS无状态组播技术可结合大规模地理密集校园网络场景的独特特性，动态高效地将组播覆盖范围扩展至每一间宿舍。