将现有的旧网络系统改造成一个新的网络系统,通常要比建造一个全新的网络系统困难得多。究其原因,主要是新的网络系统不单要考虑如何在原有网络系统的基础上进行改造,以解决新旧网络系统结构的衔接和技术性能差异所带来的问题,还要考虑改建后的系统能否满足现有应用系统对日新月异的新技术的需求。因此,新的网络系统方案的确定就要从多方面来进行认真、细致的分析、 Transforming an existing legacy network system into a new one is often more difficult than building a whole new one. The reason is mainly that the new network system not only needs to consider how to transform it based on the original network system so as to solve the problems brought by the connection between the old network system and the technical performance difference, Does it meet the needs of rapidly evolving new technologies in existing applications? Therefore, the determination of the new network system plan should be carefully and meticulously analyzed in many aspects,