【摘要】 ＳＤＨ和ＡＴＭ作为电信网的基础设施平台在数据通信领域承担了重要的角色，混合ＡＴＭ／ＳＤＨ的迭加网络结构一直被传统运营商所沿用．然而，随着ＩＰ业务的蓬勃发展，这种结构在核心网络中已不再适用．如何构建ＩＰ核心网络，使之既能兼顾成本效益因素又能快速提供服务和保护已有投资，已成为运营商必须认真考虑的问题．随着业务的扩展，传输带宽将成为限制网络发展的瓶颈，最终，传输系统的演进将奠定未来光互联网的基础．更多还原

【Abstract】 SDH and ATM, as the platform of the infrastructure of the telecom network, plays an important role in the field of data communication. Laminated network construction of mixed AMT/SDH had been used by the traditional managed merchants. However, this kind of construction has been to be not suitable for use , along with the vigorous development of IP business. How to construct the core of IP network, and make it to give consideration both the factors of cost benefit and the quick supply of service and the protection of the existent investment, has become the problem which has to be considered seriously by the merchants. Along with the extension of business, the bandwidth of transmission will be the choke point to restrict the development of network. In the end, the development of transmission system will establish the foundation of light internet in the future.更多还原