Chapter 9 Communications Circuits 94.8 Digital Subscriber Line SL) A dSL technology that provides equal speed channels in both directions and may not include a telephone channel is called SDSL VDsL transmits data at top speeds of 51 to 55 Mbps and is asymmetric www.gxmu.edu.cn9.4.8 Digital Subscriber Line (DSL) A DSL technology that provides equal speed channels in both directions and may not include a telephone channel is called SDSL. VDSL transmits data at top speeds of 51 to 55 Mbps and is asymmetric. www.gxmu.edu.cn Chapter 9 Communications Circuits