中文摘要：

Diameter协议是IETF的AAA（认证、授权、记费）工作组针对RADIUS协议的不足，提出的下一代AAA协议，设计之初就充分考虑了可扩展性、移动性和安全性，必将在移动IP尤其是MIPv6中得到广泛应用。Opendiameter是IETF组织人员开发的开源软件，实现了Diameter协议，并为进一步的开发提供了API（应用编程接口）。文中描述了Diameter基础协议和部分应用协议，并在此基础上，重点分析了Opendiameter的体系结构、线程观、基本信息处理和提供的C＋＋API。

英文摘要：

Diameter protocol is an AAA protocol of the next generation which standardized by the IETF AAA working group to meet many new requirements while RADIUS can＇ t. Diameter will surely be in extensive application with its sufficient extensibility, mobility and security. Developed and administrated by personnel of IETF , by way of openning source , Opendiameter implements Diameter protocl , and provides the Diameter C＋＋ API for further development. Diameter base protocl and part application protocls are described in this paper. Further more, the architecture, threaded view, basic message processing and C＋＋ API of Opendiameter are emphaticly analyzed here.