一年前，因特网电话还仅仅为业余爱好者使用，它的音质也十分粗糙。现在则情况大不相同了，由于其低廉的费用和改进的音质，越来越多的人已开始使用网上电话作为通信工具。同时，通信业的巨人如ＡＴ＆Ｔ、Ｂｅｌ－ｃｏｅ等公司也看上了网上电话的巨大潜力，纷纷致力于因特... A year ago, Internet telephony was used by amateurs only, and its sound quality was also very rough. The situation is now quite different, with more and more people starting to use Internet telephony as a communication tool due to their low cost and improved sound quality. Meanwhile, giants such as AT & T, Bel-coe and other companies in the communications industry have also seen the great potential of Internet telephony.