Symmetrical digital subscriber line (SDSL),

Definition of Symmetrical digital subscriber line (SDSL):

1. Single line digital subscriber line (DSL) that offers 2.3 Megabits per second (Mbps) of digital bandwidth in both (symmetric) directions over common (copper unshielded twisted pair) phone lines up to 10,000 feet without using repeaters. Also called high speed digital subscriber line version 2 (HDSL-2).