本文档描述了通过TCP/IP网络到网络访问服务器（NAS）的呼叫控制和资源管理的基于DSS1的协议。本协议适用于媒体网关控制器（MGC）和媒体网关（MG）之间ETSI EP Tiphon体系结构中的N参考点。NAS是Tiphon架构中的MG。网络访问服务器终止SCN连接，并打包数据以转发到IP网络。

This document describes the DSS1 based protocol for call control & resource management over a TCP/IP network to a Network Access Server (NAS). This protocol applies at the N reference point in the ETSI EP Tiphon architecture between the Media Gateway Controller (MGC) and the Media Gateway (MG). The NAS is the MG in the Tiphon architecture. The Network Access Server terminates the SCN connections and packetizes data for forwarding to IP networks.