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ＩＳＤＮ与ＤＤＮ介绍＠晓健ＩＳＤＮ与ＤＤＮ介绍晓健数字数据网（ＤＤＮ）是一种数据传输网，它能够支持和提供多种通信业务，因而其应用也从最初单纯提供端到端的数据通信服务，逐步拓宽到各个领域。综合业务数字网（ＩＳＤＮ）是以电话网ＰＳＴＮ为基础扩展而成的通信网，可...
Introduction to ISDN and DDN @ Xiaojian introduction of ISDN and DDN Xiaojian digital data network (DDN) is a data transmission network that can support and provide a variety of communication services, and thus its applications also simply provide end-to-end data communication services , Gradually widening to all fields. Integrated Services Digital Network (ISDN) is based on the telephone network PSTN expanded communication network, ...