1. CODEC: A codec is a chip that decodes analog-to-digital conversion and digital-to-analog.
2. TONE: A push-button telephone dial that makes a different sound (in fact, a combination of two tones) for each number pushed. The technically correct name for tone dial is dual-tone multifrequency (DTMF) since there are two tones generated for each button pressed
3. RING TOPOLOGIE: A network topology in which terminals are connected in a point-to-point serial fashion in an unbroken circular configuration. Many logical ring topologies such as Token Ring are wired as a star for greater reliability
4. BASE BAND: A method of communication in which the entire bandwidth of the transmission medium is used to transmit a single digital signal. The signal is driven directly onto the transmission medium without modulation of any kind. Baseband uses the entire bandwidth of the carrier, whereas broadband only uses part of the bandwidth. Baseband is simpler, cheaper, and less sophisticated than broadband.
5. BROADBAND: A transmission facility that has the ability to handle a variety of signals using a wide range of channels simultaneously. Broadband transmission medium has a bandwidth sufficient to carry multiple voice, video, or data channels simultaneously. Each channel occupies (is modulated to) a different frequency bandwidth on the transmission medium and is demodulated to its original frequency at the receiving end. Channels are separated by “guard bands” (empty spaces) to ensure that each channel will not interfere with its neighboring channels. For example, this technique is used to provide many CATV channels on one coaxial cable
6. CARRIER (DIAL TONE): An electrical signal of a set frequency that can be modulated in order to carry voice, video, and/or data.