xDigital Subscriber Line

xDSL is a generic term for various DSL variants that utilize telephone lines in the access area for broadband usage. The "x" represents one or two letters that characterize the specific DSL technology. If an "A" replaces the "x", it signifies asymmetric transmission with different data rates in the upstream and downstream directions. "S" represents symmetrical data rates, "I" stands for ISDN, "RA" denotes Rate Adaptive or Speed Adaptive, and so on.