A modem (modulator-demodulator) is a device that allows a computer to communicate with another computer via telephone lines. According to their appearance and installation location , modems are divided into
- internal (internal);
- external (external).
Internal modems are an electronic board installed directly into a computer, and external modems are an autonomous device.
An external modem is more expensive than an internal one of the same type due to its external attractiveness and easier installation.
The main parameter in the modem operation is the data transfer rate. It is measured in bps (baud – bits per second). Also important indicators in modern modems are the presence of error correction mode and data compression mode.
Now 2 companies actually rule the global modem market:
ZyXEL and US Robotics. They produce the fastest and highest quality modems. Expensive ZyXEL modems have the ability to reproduce voice recorded in digital mode and compress speech signals, which allows them to be used as answering machines. Also, some ZyXEL and US Robotics Courier models are equipped with a speech/data switch, built-in testing, a number identifier and other useful functions.
In recent years, the demand for modems has become quite high, because they are necessary for almost every person working on a computer. Modems allow you to quickly transfer packages of documents from one computer to another and communicate by e-mail, as well as provide access to global Internet networks.
