Modem | Networking

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Modem

Modem - Networking

Modem
A modem is a device that converts digital signals from a computer's serial port to the analog signals required for transmission over traditional telephone lines, and vice versa. Modem stands for modulator/demodulator.

Conversion is necessary because telephone lines were initially designed to handle the analog nature of the human voice, not data. Modems provide remote access to machines in the field to eliminate unnecessary site visits and provide fast access to information in the machine.

The speed of a modem is measured by the rate at which it sends and receives data. This is expressed as bits per second (bps), thousands of bits per second (Kbps) and/or Megabits per second (Mbps). The term baud is approximately equivalent to bps.

Some modems have a V number on them to express their speed and features. V32bis modems run up to 14.4 kbps, V34 modems up to 28.8 kbps, and V34plus modems up to 33.6 kbps. The most recently-adopted standard is the V.90 standard for 56 kbps modems.

Telephone lines are the cheapest way of connecting to the Net, allowing connection speeds up to about 56 kbps. No matter what your modem speed is, actual connection speed may be less than the modem's rated speed depending on the quality of the line.

Connection speed may also vary from connection to connection. You can run your Internet connection from your existing telephone line but if you do, be aware that when you are online you cannot receive or make telephone calls using that line.

You might want to get a separate line for the Internet connection or, if you have a fax line already and you don't use it a lot, you can probably utilise this connection. If you want faster connections to allow you to spend less time online, or to make your time online more interesting and more immediately interactive, you can get connected through ISDN, DSL lines or cables.