Upstream maintenance requests for the ISDN U-interface

A method for allowing upstream maintenance requests between intermediate elements in a distributed digital subscriber line (DSL) is demonstrated. A communication control algorithm embedded in software and driving the embedded operations channel (EOC) is developed that allows bidirectional EOC communications between intermediate units in a multipoint EOC configurations. The algorithm is compliant with both ANSI T1.601-1988 and Bellcore TR-TSY-000397. Through the implementation of this algorithm one can perform front panel tests from an intermediate transmission element in both transmission directions, thus easing trouble sectionalization and installation testing of a DSL.<
>