Abstract: A method and system for distinguishing valid DTMF signals from spurious DTMF noise includes detecting signals having a first signal component indicative of DTMF signals and having a second signal component having frequencies unrelated to DTMF frequencies. The second component is utilized in isolation from the DTMF frequencies of the first signal component. The analysis includes determining a signal level representative of the second signal component. If the signal level exceeds a predetermined threshold level, the first signal component is determined to be spurious noise. On the other hand, if the signal level is below the threshold level, the first signal component is passed to a DTMF-responsive system, such as a voicemail system or a voice response unit. Optionally, the operation includes requesting confirmation of the signal of interest, if the signal level of the second signal component falls within a range which includes the threshold level as its upper limit.

Abstract: A telephone having key/light control logic which enables independent and dual usage of physical key/light pairs. Firmware within the telephone's key and light control logic is provided access to special tables which have definitions for each key. When a key is depressed, a feature activation code is sent uplink to notify the PBX of the user's action. In response to receipt of the feature activation code, the PBX returns a feature indication. When the telephone receives the feature indication, it scans the tables and turns on all lights for which the feature indication matches the key definition. Within the tables, an extra definition is maintained for the standalone light. This definition is downloaded by the switch at phone initialization time along with the key definitions. If the switch defines a key definition as "local" then the user programs the definition of that key either via the phone keypad or through an application.