Command Reference Guide

142 ● dtmf threshold 3Com Router 5000 Family and Router 6000 Family
Command Reference
dtmf threshold
Purpose Use the dtmf threshold command to configure the sensitivity of DTMF digit
detection.
Use the
undo dtmf threshold command to restore the default.
Syntax dtmf threshold { analogue index value1 | digital value2 }
undo dtmf threshold { analogue | digital } index
Parameters analogue
Sets an analog voice subscriber-line.
digital
Sets a digital voice subscriber-line.
index
Index number corresponding to the threshold, an
integer in the range 0 to 12.
value1
Specifies the threshold corresponding to the specified
index.
value2
Takes 0 or 1 to set DTMF digit detection to insensitivity
or sensitivity. On an E1 voice subscriber-line, DTMF
digit detection defaults to 1.
The following table provides the description on the index numbers.
Tabl e 1 Description on the index numbers
Index numbers Indicates
0 The lower threshold of ROWMAX plus COLMAX. The input signal
which is otherwise regarded too weak is recognized as a DTMF digit
when ROWMAX + COLMAX) > 0.
The threshold is an integer in the range 0 to 5000 and defaults to
1400. A higher threshold means increased detection reliability but
decreased sensitivity.
1 The upper threshold of the maximum value of ROWMAX or
COLMAX, whichever is larger. This threshold is used for detecting
the inter-digit delay. A detected digit is regarded ended only when
max (ROWMAX, COLMAX) < 1.
The threshold is an integer in the range 0 to 5000 and defaults to
458. A smaller value means increased detection reliability but
decreased sensitivity.
2 The lower threshold of COLMAX / ROWMAX, where ROWMAX <
COLMAX. A DTMF digit is regarded ideal when COLMAX ˜
ROWMAX, because the difference between the two values is small
then. An input signal is recognized as a DTMF digit only when
(COLMAX / ROWMAX) > 2.
The threshold is an integer in the range -18 to -3 dB and defaults to
-9 dB. A higher value means increased detection reliability but
decreased sensitivity.