经公用交换电话网或综合业务数字网或电路交换公用数据网接入分组交换公用数据网的分组式数据终端设备（DTE）和数据电路终接设备（DCE）之间的接口
Interface betweendata terminal equipment(DTE) and data circuit-terminating equipment (DCE) for terminals operating in the packet mode and accessing a packet switched public data network through a public switched telephone network or an integrated service