--- chan_zap.c	2004-10-02 05:51:28.000000000 -0300
+++ chan_zap.c.mr	2004-10-02 06:03:19.000000000 -0300
@@ -160,6 +160,9 @@
 static char musicclass[MAX_LANGUAGE] = "";
 static char progzone[10]= "";
 
+//MarconiRivello
+static int mrfeatures=0;
+
 static int usedistinctiveringdetection = 0;
 
 static int use_callerid = 1;
@@ -1472,6 +1475,9 @@
 #ifdef ZAPATA_PRI
 	char *s=NULL;
 #endif
+//MarconiRivello
+        ast_dsp_set_features(p->dsp, mrfeatures & (~DSP_FEATURE_BUSY_DETECT));
+
 	char callerid[256];
 	char dest[256]; /* must be same length as p->dialdest */
 	ast_mutex_lock(&p->lock);
@@ -2259,6 +2265,9 @@
 	ast_setstate(ast, AST_STATE_UP);
 	ast_mutex_lock(&p->lock);
 	index = zt_get_index(ast, p, 0);
+//MarconiRivello
+        ast_dsp_set_features(p->dsp, mrfeatures | DSP_FEATURE_BUSY_DETECT);
+
 	if (index < 0)
 		index = SUB_REAL;
 	/* nothing to do if a radio channel */
@@ -4387,6 +4396,9 @@
 			} else {
 				i->dsp = ast_dsp_new();
 				if (i->dsp) {
+//MarconiRivello
+					mrfeatures = features;
+
 					ast_dsp_set_features(i->dsp, features);
 					ast_dsp_digitmode(i->dsp, DSP_DIGITMODE_DTMF | i->dtmfrelax);
 					if (!ast_strlen_zero(progzone))