(HDSL) A form of {Digital Subscriber Line}, providing {T1} or {E1} connections over two or three twisted-pair copper lines, respectively. Unlike most other forms of DSL HDSL is not a typical consumer service, it' s used mostly to replace traditional T1/E1 connections, such as connecting PBXes to telco offices. The advantage of HDSL over the Alternate Mark Inversion line coding scheme traditionally used on T1/E1 lines is that it requires about an order of magnitude lower bandwidth to carry the same traffic. (1998-05-18)
