Abstract: Methods and systems are provided for detecting changes in signaling in a telecommunication system and interpreting the meaning of the changed signal. Methods for detecting a change in a signal in a telecommunication system can include collecting signal information from a sample of telephone numbers, analyzing the signal information to determine whether numbers within the sample are assigned or unassigned, developing rules defining assigned and numbers, and updating the rules. Systems operable to achieve the methods may include call generators, signaling monitors, software employing a signal interpretation algorithm, and a server wherein the call generator is operable to connect to a telephone exchange, and wherein the system is operable to place calls and record signals and optionally audio messages for each call.