Using DTMF and MF Detection

Some MF digits use approximately the same frequencies as DTMF digits. Because there is a frequency overlap, if you have the incorrect kind of detection enabled, MF digits may be mistaken for DTMF digits, and vice versa. To ensure that digits are correctly detected, only one kind of detection should be enabled at any time.

Digit detection accuracy depends on two things:

• which digit is sent
• the kind of detection enabled when the digit is detected

The following tables show the digit detection errors that occur when an inappropriate detection type is enabled.

• Table 25. Errors Detecting MF Digits
• Table 26. Errors Detecting DTMF Digits

Table 25. Errors Detecting MF Digits

String Received
MF Digit Sent	Only MF Detection Enabled	Only DTMF Detection Enabled	MF and DTMF Detection Enabled
1	1		1
2	2		2
3	3		3
4	4	2*	4,2*
5	5		5
6	6		6
7	7	3*	7,3*
8	8		8
9	9		9
0	0		0
*	*		*
#	#		#
a	a		a
b	b		b
c	c		c
* = detection error

Table 26. Errors Detecting DTMF Digits

String Received
DTMF Digit Sent	Only DTMF Detection Enabled	Only MF Detection Enabled	DTMF & MF Detection Enabled
1	1		1
2	2	4*	4,2*
3	3	7*	7,3*
4	4		4
5	5	4*	4,5*
6	6	7*	7,6*
7	7		7
8	8	5*	5,8*
9	9	8*	8,9*
0	0	5*	5,0*
*	*		*
#	#	8*	8,#*
a	a	c*	c,a*
b	b	c*	c,b*
c	c	a*	a,c*
d	d	a*	a,d*
* = detection error

Click here to contact Dialogic Customer Engineering