DTMF is not Recognized Correctly When Dialing Too Fast
Last modified date: 2019/06/29 Views: 1866

In some situation like voice mail or IVR system, user needs to input numbers. If user presses the keys too fast, especially when pressing the same key, those DTMF may not be recognized correctly by phone system.


The duration of DTMF is longer than the interval of two inputs.


Decrease the DTMF duration through auto provision:

features.dtmf.duration =


It configures the duration time (in milliseconds) for each digit when a sequence of DTMF tones is played out automatically.

Note: If the time interval between two DTMF digits is less than this value, two or more same DTMF digits could be identified as one DTMF digit. This may cause the loss of one or more DTMF digits. For example, 2662 may be identified as 262. If so, you can modify the value of this parameter to a little lower than the default value.

Permitted Values Integer:
from 0 to 700 , Default 100 

You can try a value of 80 firstly. If it still doesn’t work well, configure the value to 60 or other values.

More Information

For more info, please contact Yealink Support Team for help via ticket system.

Product Type
VP59 , SIP-T57W , SIP-T54W , SIP-T53W , SIP VP-T49G , SIP-T48G , SIP-T46G , SIP-T42G , SIP-T41P , SIP-T40G , SIP-T40P , SIP-T29G , SIP-T27G , SIP-T23G , SIP-T23P , SIP-T21(P) E2 , SIP-T19(P) E2 , SIP-T42S , SIP-T58A
v73 or higher
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