Configuring DTMF detection
Introduction to DTMF
Use the following ways to detect DTMF:
Energy detection—DTMF detection is implemented by calculating the frequency spectrum of the input voice signal. The energy threshold limits the spectrum shape of the input signal. A signal is considered a valid DTMF only when all requirements are met.
Sensitivity detection—A higher DTMF detection sensitivity reduces the possibility of missing the detection of a true DTMF signal but increases the possibility of false detection; a lower DTMF detection sensitivity reduces the possibility of false detection but increases the possibility of missing the detection of a true DTMF signal.
Configuration procedure
To configure DTMF detection:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter voice subscriber line view. | subscriber-line line-number | N/A |
3. Configure the DTMF detection sensitivity. | dtmf threshold analog index value | Optional. By default, indexes 0 to 12 correspond to 1400, 458, -9, -9, -9, -9, -3, -12, -12, 30, 300, 3200, and 375, respectively. For meanings of these parameters, see HPE FlexNetwork MSR Router Series Comware 5 Voice Command Reference. This command is used by professional personnel to adjust the device in the case of DTMF detection failure. Usually, the default value is adopted. |
4. Configure the DTMF detection sensitivity level. | dtmf sensitivity-level { high | low | medium [ frequency-tolerance value ] } | Optional. By default, the DTMF detection sensitivity is low. This command is valid only for the FXS/FXO voice subscriber line. Support for the medium keyword depends on the voice card. |
5. Set the DTMF detection sensitivity. | dtmf threshold digital value | Optional. By default, the value of DTMF detection sensitivity level is 0, that is, insensitive. This command is only applicable to the BSV voice subscriber line. |