A Digital Subscriber Line (DSL) is a technology that allows digital access to customers over the present, in-place, two-wire loop
plant. The driving force behind the development of DSLs is the need to provide "Basic Access" digital service to customers as part of
Integrated Services Digital Network (ISDN). The current telephone environment, including bridged taps and mixed wire gauge loops,
intended for voice frequency transmission, presents a complex environment for wideband transmission. Furthermore, requirements are
necessary for new transmission equipment that accommodate ISDN Basic Access services and that protect the quality of old services.
This Technical Reference (TR) presents the view of Telcordia on generic technical requirements for DSL transmission technology that
will operate in the environment mentioned above.