NGN的网络附着子系统研究进展

为实现业务与接入的完全无关性，以及使固定终端具有游牧特性，下一代网络（NGN）在架构中引入了网络附着子系统（NASS），用于完成对用户附着于接入网络的管理，包括用户验证和网络地址分配、位置管理。TISPAN组织在NGN研究的R1阶段研究了NASS的内部架构和外部接口协议，并出版了正式的技术规范。R2阶段NASS主要的研究方向有两个：移动性与游牧；支持不同接入网络的架构。NASS尚存在若干问题，需要进一步研究和关注。

Research Status of Network Attachment Subsystem in NGN

The Network Attachment Subsystem (NASS) is introduced into the Next Generation Networks (NGN) architecture to enable access-independent applications and create the support for normadism. The NASS provides user management at access level including user authentication,allocation of the IP address,and location management. ETSI Technical Body TISPAN has published NGN R1 that covers NASS architecture and interface protocol. There are several remaining issues that need to be addressed in the NASS. In TISPAN-NGN R2,the study of it will be focused on mobility and nomadism,and supporting multiple types of access networks.