Method and apparatus for performing either tone analysis on a local looped-back communications path or utilizing a hybrid reflection based looped-back test to test integrity

Abstract

In one embodiment, a test tone is placed in an outbound path of a full-duplex transmission system. An echo cancellation capability is disabled, enabling an echo signal of the test tone to pass through the inbound path of the full-duplex transmission system, which echo signal is analyzed to determine the condition of the full-duplex paths. In another embodiment a standard DSP generates DTMF tones which are looped-back and tested by the DSP, under control of a CPU. The DSP is a standard DSP avoiding the need for any hardware/software modification of the DSP to perform the test mode. The tests are performed the local level, i.e. at the subscriber's location, eliminating the need for central office intervention, for example.

Dependencies are inferred from the claim text.