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进入信息时代后,一场新的以数字化为核心的技术革命正在掀起。随着Internet的流行,与Internet相关的各种新技术、新服务不断风起云涌。目前上网的方式有很多种,有Modem(调制解调器,速率有33.6k、56k bps)、ISDN(综合业务数字网)、DDN(数字专线)等。“兵器”选择相比之下,还是ISDN最具潜刀。因为传统的电话网传输的是模拟信号,传输数据时,则需Modem进行多次数/模、模/数转换,速率低(目前最快的也只有56k bps),信号衰减,缺乏安全性;通常一根电话线仅能提供电话的单纯业务。DDN虽然在速率、安全性、业务多样性方面都做的不错,只是费用太过昂贵,非普通大众所能接受的,所以也不适合家庭使用。而ISDN
After entering the information age, a new digitized technology revolution is setting off. With the popularity of the Internet, various new technologies and services related to the Internet are constantly surging. Currently there are many ways to access the Internet, Modem (modem, the rate of 33.6k, 56k bps), ISDN (Integrated Services Digital Network), DDN (Digital Line) and so on. “Weapon ” In contrast, or ISDN most submarine knife. Because the traditional telephone network transmits analog signals, the modem needs Modem to perform multiple digital / analog / digital conversion at a low rate (currently 56k bps is the fastest), signal attenuation and lack of security; A telephone line can only provide a simple business phone. Although DDN does a good job in terms of speed, security, and business diversification, the cost is too high for the average general public to accept and is not suitable for home use. ISDN