SDSL

A kind of DSL, specifically a Symmetric Digital Subscriber Line, as opposed to an Asymmetric Digital Subscriber Line. An ADSL has different downstream and upstream data rates, while on an SDSL they are equal.

Rather confusingly, the SDSL acronym sometimes refers to Single line DSL. SDSL needs just one twisted pair line, whereas some other earlier DSL standards needed two, or even three pairs.

SymmetricDSL is almost restricted to business use, costing more than ADSL and offering the home user no significant advantage. 1 MBIT ADSL typically offers a 256 kbps upstream that is more than sufficient for home use.