and long distance and Inter-Exchange (IXC). In 1996, legislation was enacted into law, and the local exchange carriers were re-designated into incumbent (ILEC) and competitive (CLEC) categories. Carrier is also a technical term applied to carrier signals, such as the carrier signal of a radio or television station transmitter. Sub- carriers are sometimes placed on carrier signals and modulated in similar fashion as carriers. Occasionally, a T1 transmission channel is referred to as a T1 Carrier because the 1.544Mbs digital stream carries 24 discrete channels of 64Kbs each. CODEC A truncation of the words encode and decode, sometimes in capital letters, it is also used in communications network elements to describe a device that is full-duplex (i.e., it sends and receives simultaneously). The term is occasionally applied to electrical-to- optical and optical-to-electrical converters used to interface SMPTE 259 or SMPTE 292 television signals to optical fiber transmission facilities. Convergence Using a common access and/or transport facility to carry disparate traffic is called convergence. Configuring a single network channel SO it can carry Voice, Data, Video, and Internet traffic instead of using individual E1/T1 or E3/DS3 channels for GLOSSARY each traffic type is more efficient and typically lowers unit cost of bandwidth. However, this results in putting all the eggs in one basket and may not meet availability, reliability, robustness, or any of the three requirements. So-called Triple Play Networks are claimed to be capable of carrying voice, data, and video. Compression and Decompression Sometimes used interchange- ably with encoding and decoding, respectively, but compression and decompression are entirely different processes. Compression can be either lossy or loss-less. Most compression used today is lossy, meaning that some part of the information from the original signal or file will be missing upon decompression. Choosing the amount and parameters of the compression process should be done within the c