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现在的商业用户和个人用户在Internet上传输多媒体信息的数量不断增长,用户迫切需要成本低廉、安装方便的高速数字传输手段。ISDN成本太高,技术复杂度令人望而生畏。56KModem提升的速度也有限。租用线路又不是一般公司和个人所能承担得起。 这一切都成为DSL技术发展的巨大动力。随着网络通信量的增加,越来越多的服务商为用户提供新的服务项目。本地电话公司、长途电话公司、卫星通信商和有线电视公司都为DSL
With the increasing number of commercial and personal users transmitting multimedia information on the Internet, users are in desperate need of high-speed digital transmission with low cost and convenient installation. ISDN costs are too high, technical complexity is daunting. 56KModem upgrade speed is limited. Leased lines are not affordable for average companies and individuals. All this has become a huge driving force for the development of DSL technology. With the increase of network traffic, more and more service providers provide users with new service items. Local telephone companies, long distance carriers, satellite carriers and cable companies are all DSL