First, we introduced the development from traditional S12 exchange network to NGN and the reconstruction of S12 exchange.Then we introduced the topological structure and control protocol of the NGN.

• 论文首先介绍了传统S12交换机网络到NGN网络的转换方法及S12交换机所需进行的改造，以及改造后NGN网络的拓扑结构和控制协议。