中文摘要：

为了解决现有多播存在的问题，加速多播的应用，近年来提出了应用层多播（ALM）。根据ALM构建转发树的策略，可以将应用层多播分成集中式和分布式两类。由于ALM的开放性带来了一定的安全隐患，我们引入RBAC来解决该问题。该文基于集中式ALM的特点，提出了相应的RBAC模型-CALM—RBAC，并对该模型进行了UML语言的描述。

英文摘要：

To solve the existing problems and accelerate the deployment of multicast, there has been proposed the application level muhicast. ALM is classified by centralized or distributed approach. ALM is free for anyone to join, which brings vulnerability to the system. In this paper, we give a RBAC model named CALM - RBAC to face the vulnerability. We still give the UML - based representation of the CALM - RBAC.