之后，分别阐述了下一代网络体系的四级功能层：即接入层、传输层、控制层和业务层。

NGN has been divided into four different function layers, they are separately access function layer transfer function layer control function layer and service function layer.

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对基于SNMP协议的网管技术做了简单介绍，结合安阳有线数据网络介绍了接入层网管系统的应用实例。

It also briefly introduces the web management technology based on the SNMP agreement and the actual use example of connect the lay web management according to Anyang cable data network.

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为了保证通用性，通用网络接入子系统划分为核心层和适配器层两个层次，它们各有不同的目标。

For the universal ability of network connect, UNCS is divided into two layers, Kernel layer and Adapter layer, and they have different target.

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