ISDN Physical Layer Interfaces

This talk presents the status of the standards activities, both at the international and national level, on the ISDN physical layer interfaces. In the international arena, the CCITT of the ITU (a UN agency) has been actively defining Recommendations for ISDNs for several years now. It came out with its first set of Recommendations on ISDNs at the end of 1984 and is now busy updating some of those and defining new ones. Closely related to the CCITT activities is the work of the ANSI accredited committee T1D1, on industry sponsored standards on ISDNs.