Index: configs/dsp.conf.sample
===================================================================
--- configs/dsp.conf.sample	(revision 374095)
+++ configs/dsp.conf.sample	(working copy)
@@ -5,3 +5,34 @@
 ; to talking.  [default=256]
 ;
 ;silencethreshold=256
+
+; DTMF Reverse Twist and Normal Twist is the difference in power between the row and column energies.
+;
+; Normal Twist is where the Column energy is greater than the Row energy
+; Reverse Twist is where the Row energy is greater.
+;
+; Power level difference between frequencies for different Administrations/RPOAs
+;		Power Gain		equiv
+;		normal	reverse		dB's
+; AT&T(default) 6.31	2.51		8dB(normal), 4dB(reverse)
+; NTT		3.16	3.16		Max. 5dB
+; Danish	3.98	3.98		Max. 6dB
+; Australian	10.0	10.0		Max. 10dB
+; Brazilian	7.94	7.94		Max. 9dB
+; ETSI		3.98	3.98		Max. 6dB
+
+;previous version compatible AT&T values
+; RADIO_RELAX disabled, and relaxdtmf=no
+;		6.30	2.50		7.99dB(normal), 3.98dB(reverse)
+; RADIO_RELAX disabled, and relaxdtmf=yes
+;		6.30	4.00		7.99dB(normal), 6.02dB(reverse)
+; RADIO_RELAX enabled, and relaxdtmf=no
+;		6.30	2.50		7.99dB(normal), 3.984dB(reverse)
+; RADIO_RELAX enabled, and relaxdtmf=yes
+;		6.30	6.50		7.99dB(normal), 8.13dB(reverse)
+
+;If you don't know what these mean, don't change them.
+;dtmfnormaltwist=6.31
+;dtmfreversetwist=2.51
+;relaxdtmfnormaltwist=6.31
+;relaxdtmfreversetwist=3.98
Index: main/dsp.c
===================================================================
--- main/dsp.c	(revision 374095)
+++ main/dsp.c	(working copy)
@@ -146,7 +146,7 @@
 
 #define	MAX_DTMF_DIGITS		128
 
-/* Basic DTMF specs:
+/* Basic DTMF (AT&T) specs:
  *
  * Minimum tone on = 40ms
  * Minimum tone off = 50ms
@@ -161,12 +161,18 @@
 #define DTMF_THRESHOLD		8.0e7
 #define FAX_THRESHOLD		8.0e7
 #define FAX_2ND_HARMONIC	2.0     /* 4dB */
-#define DTMF_NORMAL_TWIST	6.3     /* 8dB */
+
+#define DEF_DTMF_NORMAL_TWIST		6.31	 /* 8.0dB */
+#define DEF_RELAX_DTMF_NORMAL_TWIST	6.31	 /* 8.0dB */
+
 #ifdef	RADIO_RELAX
-#define DTMF_REVERSE_TWIST          (relax ? 6.5 : 2.5)     /* 4dB normal */
+#define DEF_DTMF_REVERSE_TWIST		2.51	 /* 4.01dB */
+#define DEF_RELAX_DTMF_REVERSE_TWIST	6.61	 /* 8.20dB */
 #else
-#define DTMF_REVERSE_TWIST          (relax ? 4.0 : 2.5)     /* 4dB normal */
+#define DEF_DTMF_REVERSE_TWIST		2.51	 /* 4.01dB */
+#define DEF_RELAX_DTMF_REVERSE_TWIST	3.98	 /* 6.00dB */
 #endif
+
 #define DTMF_RELATIVE_PEAK_ROW	6.3     /* 8dB */
 #define DTMF_RELATIVE_PEAK_COL	6.3     /* 8dB */
 #define DTMF_2ND_HARMONIC_ROW       (relax ? 1.7 : 2.5)     /* 4dB normal */
@@ -307,6 +313,11 @@
 static const char bell_mf_positions[] = "1247C-358A--69*---0B----#";
 static int thresholds[THRESHOLD_MAX];
 
+static float dtmfnormaltwist;		/* AT&T 8dB */
+static float dtmfreversetwist;		/* AT&T 4dB */
+static float relaxdtmfnormaltwist;	/* AT&T 8dB */
+static float relaxdtmfreversetwist;	/* AT&T 6dB */
+
 static inline void goertzel_sample(goertzel_state_t *s, short sample)
 {
 	int v1;
@@ -709,8 +720,8 @@
 		/* Basic signal level test and the twist test */
 		if (row_energy[best_row] >= DTMF_THRESHOLD && 
 		    col_energy[best_col] >= DTMF_THRESHOLD &&
-		    col_energy[best_col] < row_energy[best_row] * DTMF_REVERSE_TWIST &&
-		    col_energy[best_col] * DTMF_NORMAL_TWIST > row_energy[best_row]) {
+		    col_energy[best_col] < row_energy[best_row] * (relax ? relaxdtmfreversetwist : dtmfreversetwist) &&
+		    col_energy[best_col] * (relax ? relaxdtmfnormaltwist : dtmfnormaltwist) > row_energy[best_row]) {
 			/* Relative peak test */
 			for (i = 0;  i < 4;  i++) {
 				if ((i != best_col &&
@@ -1741,6 +1752,10 @@
 	if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
 		ast_verb(5, "Can't find dsp config file %s. Assuming default silencethreshold of %d.\n", CONFIG_FILE_NAME, DEFAULT_SILENCE_THRESHOLD);
 		thresholds[THRESHOLD_SILENCE] = DEFAULT_SILENCE_THRESHOLD;
+		dtmfnormaltwist = DEF_DTMF_NORMAL_TWIST;
+		dtmfreversetwist = DEF_DTMF_REVERSE_TWIST;
+		relaxdtmfnormaltwist = DEF_RELAX_DTMF_NORMAL_TWIST;
+		relaxdtmfreversetwist = DEF_RELAX_DTMF_REVERSE_TWIST;
 		return 0;
 	}
 
@@ -1759,6 +1774,38 @@
 			thresholds[THRESHOLD_SILENCE] = DEFAULT_SILENCE_THRESHOLD;
 		}
 
+		value = ast_variable_retrieve(cfg, "default", "dtmfnormaltwist");
+		if (value && sscanf(value, "%30f", &dtmfnormaltwist) != 1) {
+			ast_verb(5, "%s: '%s' is not a valid dtmfnormaltwist value\n", CONFIG_FILE_NAME, value);
+			dtmfnormaltwist = DEF_DTMF_NORMAL_TWIST;
+		} else if (!value) {
+			dtmfnormaltwist = DEF_DTMF_NORMAL_TWIST;
+		}
+
+		value = ast_variable_retrieve(cfg, "default", "dtmfreversetwist");
+		if (value && sscanf(value, "%30f", &dtmfreversetwist) != 1) {
+			ast_verb(5, "%s: '%s' is not a valid dtmfreversetwist value\n", CONFIG_FILE_NAME, value);
+			dtmfreversetwist = DEF_DTMF_REVERSE_TWIST;
+		} else if (!value) {
+			dtmfreversetwist = DEF_DTMF_REVERSE_TWIST;
+		}
+
+		value = ast_variable_retrieve(cfg, "default", "relaxdtmfnormaltwist");
+		if (value && sscanf(value, "%30f", &relaxdtmfnormaltwist) != 1) {
+			ast_verb(5, "%s: '%s' is not a valid relaxdtmfnormaltwist value\n", CONFIG_FILE_NAME, value);
+			relaxdtmfnormaltwist = DEF_RELAX_DTMF_NORMAL_TWIST;
+		} else if (!value) {
+			relaxdtmfnormaltwist = DEF_RELAX_DTMF_NORMAL_TWIST;
+		}
+
+		value = ast_variable_retrieve(cfg, "default", "relaxdtmfreversetwist");
+		if (value && sscanf(value, "%30f", &relaxdtmfreversetwist) != 1) {
+			ast_verb(5, "%s: '%s' is not a valid relaxdtmfreversetwist value\n", CONFIG_FILE_NAME, value);
+			relaxdtmfreversetwist = DEF_RELAX_DTMF_REVERSE_TWIST;
+		} else if (!value) {
+			relaxdtmfreversetwist = DEF_RELAX_DTMF_REVERSE_TWIST;
+		}
+
 		ast_config_destroy(cfg);
 	}
 	return 0;