ABSTRACT: A Universal Digital Channel (UDC) system consists of a Central Office Terminal (COT), a Remote Digital Terminal (RDT), and the Digital
Subscriber Line (DSL) transport facility. Functionally, the UDC is a small Digital Loop Carrier (DLC) system. It uses the 2-wire
transmission technology developed for Integrated Services Digital Network (ISDN) Basic Access, known as the DSL, to provide a variety
of services over a single pair (loop).
This Technical Reference (TR) presents the Telcordia view of the overall system functions required to support a UDC in the local
telephone loop. It describes various ways in which UDC can be deployed and defines the generic requirements and objectives for each
This TR describes service interfaces that can be provided by a UDC defines the relevant service parameters, and provides the generic
requirements for powering, monitoring, and testing the UDC equipment.
Revision 1 replaces Bulletin 1. It revises the TR to include generic requirements for the use of dc signatures by the UDC Self-Test
Interface and provides a section on metallic access to the DSL.
Modifications to existing criteria are also made to clarify the existing criteria. Specifically, Section 6, "Operations
Interfaces," and Section 7, "Operations Features," are combined into Section 7 under the heading "Maintenance Capabilities and