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.