使用计算机、MODEM和电话线相连,拨号上网是绝大多数用户访问互联网的方法。在这样一套系统中,是用串行电缆将MODEM连接到计算机的串行通讯口上,再将电话线与MODEM相连,从而建立用户的计算机终端与互联网的物理连接,再通过使用特定的网络访问软件,实现用户对互联网信息的访问。因此,正确地连接计算机MODEM和电话线是实现上 Using a computer, modem and telephone lines connected, dial-up Internet access is the vast majority of Internet users. In such a system, a serial cable is used to connect the MODEM to the serial communication port of the computer, and then the telephone line is connected to the MODEM to establish a physical connection between the user’s computer terminal and the Internet, and then use a specific network access Software, to achieve the user’s access to Internet information. Therefore, the correct connection between the computer modem and the telephone line is achieved