Patent ID: 8755514

Claim:
A system, comprising: a high frequency identification component configured to identify a high frequency of a dual-tone multi-frequency signal; a low frequency identification component configured to identify a low frequency of the dual-tone multi-frequency signal; a classification component configured to determine a classification of the dual-tone multi-frequency signal based, at least in part, on the high frequency and a low frequency; a calculation component configured to calculate a confidence level of the classification; a comparison component configured to compare the confidence level against a threshold to produce a comparison result; an output component configured to: output the classification if the comparison result is such that the confidence level meets the threshold and output an error message if the comparison result is such that the confidence level does not meet the threshold; and a non-transitory computer-readable medium configured to retain an information set that pertains to operation of the high frequency identification component, the low frequency identification component, the classification component, the calculation component, the comparison component, the output component, or a combination thereof.