3Com MSR 30, MSR 50 manual Upper limit of the maximum To 4,999, with

2590 CHAPTER 173: VOIP CONFIGURATION COMMANDS

Table 682 Meaning of the index numbers

Index	Meaning	Value range	Remarks
1	The upper limit of the maximum	1 to 4,999, with	The smaller the value is,
	value of ROWMAX or COLMAX,	a default of 458	the higher the detection
	whichever is larger. This limit is used		reliability is. However,
	for detecting the inter-digit delay. A		the sensitivity drops.
	detected digit is regarded ended only
	when max (ROWMAX, COLMAX) <
	1.

2The lower limit of COLMAX/ROWMAX, where ROWMAX < COLMAX. An input signal is recognized as a DTMF digit only when 10 x (COLMAX/ROWMAX) > 2.

-18 to -3 dB, with a default of -9 dB.

The larger the value is, the higher the detection reliability is. However, the sensitivity drops.

3The lower limit of ROWMAX/COLMAX when COLMAX Š ROWMAX. The function is similar to that of index 2. An input signal is recognized as a DTMF digit only when 10 x (ROWMAX/COLMAX) > 2.

-18 to -3 dB, with a default of -9 dB.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

4The upper limit of the ratio of the second largest energy level from the row frequency group to ROWMAX. The ratio must be lower than this limit for the input signal to be recognized as a DTMF digit.

-18 to -3 dB, with a default of -9 dB.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

5	The upper limit of the ratio of the
	second largest energy level from the
	column frequency group to
	COLMAX. The ratio must be lower
	than this limit for the input signal to
	be recognized as a DTMF digit.
6	The upper limit of
	ROW2nd/ROWMAX. An input signal
	is recognized as a DTMF digit only
	when ROW2nd/ROWMAX < 6.

-18 to -3 dB, with a default of -9 dB.

-18 to -3 dB, with a default of -3 dB.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

7	The upper limit of
	COL2nd/COLMAX. The ratio must
	be lower than this limit for the input
	signal to be recognized as a DTMF
	digit.
8	The upper limit of the ratio of the
	maximum energy level of two extra
	specified frequency points to max
	(ROWMAX, COLMAX). The ratio
	must be greater than this upper limit
	for the input signal to be recognized
	as a DTMF digit.
9	The lower limit of the DTMF signal
	duration. The duration of DTMF key
	tone must be larger than this
	threshold for the input signal to be
	recognized as a DTMF digit.

-18 to -3 dB, with a default of -12 dB.

-18 to -3 dB, with a default of -12 dB.

30 to 150 milliseconds, with a default of 30 milliseconds.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

The smaller the value is, the higher the detection reliability is. However, the sensitivity drops.

The larger the value is, the higher the detection reliability is. However, the sensitivity drops.