R0106-HP MSR Router Series Voice Configuration Guide(V7)

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A DTMF tone must last at least 45 milliseconds. A minimum interval of 23 milliseconds is required
between two DTMF tones to make sure DTMF tones are recognizable. Such requirements are roughly the
same in all countries. For more information, see the ITU-T Recommendation Q.24.
Configuring DTMF tone sending
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter voice view.
voice-setup N/A
3. Configure the duration of
DTMF tones and the interval
between DTMF tones.
dtmf time {interval | persist }
milliseconds
The default duration and interval
are both 120 milliseconds.
4. Configure the amplitude of
DTMF tones.
dtmf amplitude value The default is –9.0 dBm.
Configuring DTMF tone detection
Perform this task to configure the threshold parameters and sensitivity level for DTMF detection.
• The threshold parameters are used to determine whether a DTMF tone is valid. The system
calculates the spectrum shape of input DTMF signals and matches the spectrum shape with the
threshold parameters. A DTMF tone is considered valid if it matches all threshold parameters.
• The sensitivity level is a trade-off between detection sensitivity and reliability. A higher DTMF
detection sensitivity reduces the possibility of missing a true DTMF tone but increases the possibility
of false detection. A lower DTMF detection sensitivity reduces the possibility of false detection but
increases the possibility of missing a true DTMF tone.
To configure DTMF tone detection:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter voice interface view.
subscriber-line line-number N/A
3. Configure the threshold
parameters for DTMF
detection.
dtmf threshold analog index
value
By default, indexes 0 to 12 correspond to
1400, 458, -9, -9, -9, -9, -3, -12, -12, 30,
300, 3200, and 375, respectively.
This command is used by professional
personnel to adjust the device in the case
of DTMF detection failure. Typically, the
default value is used.
4. Configure the DTMF
detection sensitivity level.
dtmf sensitivity-level { high |
low | medium
[ frequency-tolerance value ] }
By default, the DTMF detection sensitivity
is low.
This command is supported only on
routers installed with the interface module
SIC-2FXS1FXO, HMIM-8FXS8FXO,
DSIC-4FXS1FXO, or HMIM-16FXS.