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1.1 The Telephone Loop Plant
1.2 DSL Reference Model
1.3 The Family of DSL Technologies
1.4 DSL Protocol Reference Model
Digital subscriber line (DSL) technology transforms an ordinary telephone line into a broadband communications link, much like adding express lanes to an existing highway. DSL increases data transmission rates by a factor of twenty or more by sending signals in previously unused high frequencies. DSL technology has added a new twist to the utility of twisted-pair telephone lines.