日前,以色列Vocal Tec公司和美国佳网公司开发出用于网络通话的技术软件。现在,用户可以直接用普通电话进行网络通话。其费用相当于传统话费的几分之一。 众所周知,目前因特网上广泛传递的是文字、图像及数据信息。其实,传统的以模拟信号传输的声音信号也可以被数字化,像其它类型的数据一样在因特网上传送,从而彻底改变传统的通讯方式。 简单说,网络通话的原理是这样的:网关(Cateway,可以看做中转站)一方面与公共交换电话网(PSTN)进而与用户电话机相连。用户语 Recently, Israel Vocal Tec Corporation and the United States Jianet company developed for the network call technology software. Now, users can directly use the ordinary telephone network calls. The cost is equivalent to a fraction of the traditional bill. As we all know, the texts, images and data are widely transmitted on the Internet. In fact, the traditional analog signal transmission of sound signals can also be digitized, like other types of data transmitted on the Internet, thus completely changing the traditional means of communication. In short, the principle of Internet calling is this: The gateway (Cateway, which can be seen as a transit point) is connected, on the one hand, to the public switched telephone network (PSTN) and then to the user’s telephone. User language