ZyXEL Elite 2864 User Guide - Page 27

Chapter 2 MODEM AND FAX BASICS This chapter is intended for those readers who want to know the details behind modem and fax operations; what's going on behind the scenes. In addition to introducing basic modem and fax terminology, this chapter helps users to understand and be able to utilize the available features. Experienced modem and fax users may wish to skip this chapter. Modem Modem is a compound word of MOdulator and DEModulator. A modem is used for computer communications. Refer to Fig. 2.1 for a standard modem setup and application. Modem Modem Fig. 2.1: Modems are used in computer communications. A modem translates computer data to analog signals (modulation) that can travel through the telephone network and reach another modem. The remote modem translates the analog signal received back into data (demodulation) and sends the information to the receiving-end computer. Modems are telephones for computers, what they use to talk to each other. DTE and DCE DTE and DCE are terminologies used in data communication. DTE stands for Data Terminal Equipment and DCE stands for Data Circuit terminating Equipment (Data Communication Equipment). Referring to Fig. 2.1, the computer or terminal is the DTE and the modem is the DCE. 2-1