LAN和ISDN构成互连一体化网络的经济性分析和总体设计

Economic Analysis and Overall Design of Organic Interconnected Network Composed by LAN and ISDN

ＩＳＤＮ的线路结构是从ＰＴＮ（公用电话网）发展而来的，如果发展中国家按发达国家的模式发展ＩＳＤＮ，就不得不花费更多的投资先用于ＰＴＮ的建设．近期的研究表明，ＬＡＮ的传输能力可以在某种程度上满足话音类等时信息的传输要求，并且在不影响ＬＡＮ操作系统完整性的前提下，可以在ＬＡＮ中综合进电信业务．把ＬＡＮ改造为综合业务局域网（ＩＳＬＮ），可以满足工作组的综合业务要求，花费少于ＩＳＤＮ终端的费用，并且可以促进公用ＩＳＤＮ的发展，如果发展中国家首先建设ＩＳＬＮ，那么就能加快公用ＩＳＤＮ的建设．文中比较了ＩＳＬＮ相对于ＩＳＤＮ的费用，并详细讨论了ＩＳＬＮ的具体设计．

The line structure of an ISDN is evolved from the structure of PTN (Public Telephony Networks). If developing countries construct ISDNs by following the practice of developed countries, they will have to spend much more money. Recent studies showed that the transmission ability of LANs can fulfill the requirements of the transmission of voicetype synchronous information to some extent. And it is feasible to integrate teleservices into LAN operating systems under the condition of not disturbing the original completeness. The transformation of LANs into integrated services local networks(ISLN), in which ISDN services are provided and can fulfill the requirements of workgroups, costs less than ISDN terminals, and can motivate the public ISDN. If a developing country constructs ISLNs at first,the construction of the public ISDN will be sped up. This paper compares the cost of ISLN with that of ISDN and the design of ISLN is introduced in detail.