NEX NYNEX merged with Bell Atlantic in 1996 to become Verizon. Pacific Bell (PacBell) PacBell was acquired by SBC in 1996. BellSouth BellSouth has been acquired by SBC/AT&T. Telecom Glossary Ameritech Ameritech was acquired by SBC in 1998. US West US West was acquired by Qwest Communications in 2000. Smart jack A smart jack is a device that terminates a digital circuit. It is considered "smart" because the phone company can control it remotely. Smart jacks also offer test points for equipment such as BERT testers. T1s are usually terminated at smart jacks. Larger installations have racks of smart jacks called smart jack racks. SONET SONET (pronounced like bonnet) is short for synchronous optical network. SONET is an ANSI standard for fiber-optic transmission systems. The equiva- lent European standard is called the synchronous digital hierarchy (SDH). SONET is strictly optical, as its name suggests, and is very fast. SONET defines certain optical carrier levels, as shown in Table 19-4. Table 19-4. Optical carrier levels Optical carrier level Line rate Payload rate 51 Mbps 50 Mbps 155 Mbps 150 Mbps 622 Mbps 601 Mbps 2,488 Mbps 2,405 Mbps 0C192 9,953 Mbps 9,621 Mbps 0C768 39,813 Mbps 38,486 Mbps T-carrier T-carrier is the generic name for digital multiplexed carrier systems. The letter T stands for trunk, as these links were originally designed to trunk multiple phone lines between central offices. The T-carrier hierarchy is used in the U.S. and Canada. Europe uses a similar scale called the European E-carrier hierarchy, and Japan uses a system titled the Japanese J-carrier hierarchy. The North American T-carrier hierarchy is shown in Table 19-5. Table 19-5. North American T-carrier hierarchy Designator Transmission rate Voice channels 1.544 Mbps 3.152 Mbps 6.312 Mbps 44.736 Mbps 274.176 Mbps 4,032 Chapter 19: Telecom Nomenclature T-Berd A T-Berd is a T1 Bit Error Rate Detector. The generic term is used for any device that will perform BERT tests on a T1. If you have a T1 that's misbehaving, the provider will proba