【摘要】 介绍AAA服务协议及其应用的基本模型。接着分析移动IP、NASREQ、ROAMOPS等新兴应用的特点和对AAA服务的功能需求,现有AAA服务协议RADIUS和TACACS+的内在不足以及与新的应用需求之间的差距。研究和分析指出Diameter协议不但能胜任现有应用对AAA的功能要求，而且完全满足新兴应用的需求。更多还原

【Abstract】 At first, the definition of AAA and the basic model for AAA service are introduced. Then, the characteristics of new Internet applications, such as Mobile-IP, ROAMREQ and NASREQ, and their requirements for AAA service are described. And the limitations and disadvantages of current AAA protocols, RADIUS and TACACS+, are also set out. At last, Diameter protocol is introduced, which will provide AAA service for the Internet in the future.更多还原