Index: channels/chan_zap.c
===================================================================
--- channels/chan_zap.c	(revision 113646)
+++ channels/chan_zap.c	(working copy)
@@ -648,6 +648,8 @@
 	int busy_tonelength;
 	int busy_quietlength;
 	int callprogress;
+	int waitfordialtone;
+	struct timeval waitingfordt;			/*!< Time we started waiting for dialtone */
 	struct timeval flashtime;			/*!< Last flash-hook time */
 	struct ast_dsp *dsp;
 	int cref;					/*!< Call reference number */
@@ -2113,6 +2115,7 @@
 		ast_mutex_unlock(&p->lock);
 		return -1;
 	}
+	p->waitingfordt.tv_sec = 0;
 	p->dialednone = 0;
 	if ((p->radio || (p->oprmode < 0)))  /* if a radio channel, up immediately */
 	{
@@ -2336,6 +2339,21 @@
 			p->dop.dialstr[strlen(p->dop.dialstr)-2] = '\0';
 		} else
 			p->echobreak = 0;
+
+		/* waitfordialtone ? */
+#ifdef ZAPATA_PRI
+		if (!p->pri) {
+#endif
+			if( p->waitfordialtone && CANPROGRESSDETECT(p) && p->dsp ) {
+				ast_log(LOG_DEBUG, "Defer dialling for %dms or dialtone\n", p->waitfordialtone);
+				gettimeofday(&p->waitingfordt,NULL);
+				ast_setstate(ast, AST_STATE_OFFHOOK);
+				break;
+			}
+#ifdef ZAPATA_PRI
+		}
+#endif
+
 		if (!res) {
 			if (ioctl(p->subs[SUB_REAL].zfd, ZT_DIAL, &p->dop)) {
 				x = ZT_ONHOOK;
@@ -3261,6 +3279,7 @@
 		p->callwaitcas = 0;
 		p->callwaiting = p->permcallwaiting;
 		p->hidecallerid = p->permhidecallerid;
+		p->waitingfordt.tv_sec = 0;
 		p->dialing = 0;
 		p->rdnis[0] = '\0';
 		update_conf(p);
@@ -4996,6 +5015,7 @@
 		case ZT_EVENT_HOOKCOMPLETE:
 			if (p->inalarm) break;
 			if ((p->radio || (p->oprmode < 0))) break;
+			if (p->waitingfordt.tv_sec) break;
 			switch (mysig) {
 			case SIG_FXSLS:  /* only interesting for FXS */
 			case SIG_FXSGS:
@@ -5449,7 +5469,7 @@
 		p->subs[index].f.data = NULL;
 		p->subs[index].f.datalen= 0;
 	}
-	if (p->dsp && (!p->ignoredtmf || p->callwaitcas || p->busydetect  || p->callprogress) && !index) {
+	if (p->dsp && (!p->ignoredtmf || p->callwaitcas || p->busydetect  || p->callprogress || p->waitingfordt.tv_sec) && !index) {
 		/* Perform busy detection. etc on the zap line */
 		int mute;
 
@@ -5481,6 +5501,36 @@
 #endif				
 				/* DSP clears us of being pulse */
 				p->pulsedial = 0;
+			} else if (p->waitingfordt.tv_sec) {
+				if (ast_tvdiff_ms(ast_tvnow(), p->waitingfordt) >= p->waitfordialtone ) {
+					p->waitingfordt.tv_sec = 0;
+					ast_log(LOG_WARNING, "Never saw dialtone on channel %d\n", p->channel);
+					f=NULL;
+				} else if (f->frametype == AST_FRAME_VOICE) {
+					f->frametype = AST_FRAME_NULL;
+					f->subclass = 0;
+					if (ast_dsp_get_tstate(p->dsp) == DSP_TONE_STATE_DIALTONE && ast_dsp_get_tcount(p->dsp) > 9) {
+						p->waitingfordt.tv_sec = 0;
+						p->dsp_features &= ~DSP_FEATURE_WAITDIALTONE;
+						ast_dsp_set_features(p->dsp, p->dsp_features);
+						ast_log(LOG_DEBUG, "Got 10 samples of dialtone!\n");
+						if (!ast_strlen_zero(p->dop.dialstr)) { /* Dial deferred digits */
+							res = ioctl(p->subs[SUB_REAL].zfd, ZT_DIAL, &p->dop);
+							if (res < 0) {
+								ast_log(LOG_WARNING, "Unable to initiate dialing on trunk channel %d\n", p->
+channel);
+								p->dop.dialstr[0] = '\0';
+								return NULL;
+							} else {
+								ast_log(LOG_DEBUG, "Sent deferred digit string: %s\n", p->dop.dialstr);
+								p->dialing = 1;
+								p->dop.dialstr[0] = '\0';
+								p->dop.op = ZT_DIAL_OP_REPLACE;
+								ast_setstate(ast, AST_STATE_DIALING);
+							}
+						}
+					}
+				}
 			}
 		}
 	} else 
@@ -5892,6 +5942,8 @@
 			features |= DSP_FEATURE_BUSY_DETECT;
 		if ((i->callprogress & CALLPROGRESS_PROGRESS) && CANPROGRESSDETECT(i))
 			features |= DSP_FEATURE_CALL_PROGRESS;
+		if ((i->waitfordialtone) && CANPROGRESSDETECT(i))
+			features |= DSP_FEATURE_WAITDIALTONE;
 		if ((!i->outgoing && (i->callprogress & CALLPROGRESS_FAX_INCOMING)) || 
 		    (i->outgoing && (i->callprogress & CALLPROGRESS_FAX_OUTGOING))) {
 			features |= DSP_FEATURE_FAX_DETECT;
@@ -8431,6 +8483,7 @@
 		tmp->busy_tonelength = conf.chan.busy_tonelength;
 		tmp->busy_quietlength = conf.chan.busy_quietlength;
 		tmp->callprogress = conf.chan.callprogress;
+		tmp->waitfordialtone = conf.chan.waitfordialtone;
 		tmp->cancallforward = conf.chan.cancallforward;
 		tmp->dtmfrelax = conf.chan.dtmfrelax;
 		tmp->callwaiting = tmp->permcallwaiting;
@@ -13319,6 +13372,8 @@
 			confp->chan.callprogress &= ~CALLPROGRESS_PROGRESS;
 			if (ast_true(v->value))
 				confp->chan.callprogress |= CALLPROGRESS_PROGRESS;
+		} else if (!strcasecmp(v->name, "waitfordialtone")) {
+			confp->chan.waitfordialtone = atoi(v->value);
 		} else if (!strcasecmp(v->name, "faxdetect")) {
 			confp->chan.callprogress &= ~CALLPROGRESS_FAX;
 			if (!strcasecmp(v->value, "incoming")) {
Index: include/asterisk/dsp.h
===================================================================
--- include/asterisk/dsp.h	(revision 113646)
+++ include/asterisk/dsp.h	(working copy)
@@ -41,6 +41,7 @@
 #define DSP_PROGRESS_BUSY		(1 << 18)		/*!< Enable busy tone detection */
 #define DSP_PROGRESS_CONGESTION		(1 << 19)		/*!< Enable congestion tone detection */
 #define DSP_FEATURE_CALL_PROGRESS	(DSP_PROGRESS_TALK | DSP_PROGRESS_RINGING | DSP_PROGRESS_BUSY | DSP_PROGRESS_CONGESTION)
+#define DSP_FEATURE_WAITDIALTONE	(1 << 20)		/*!< Enable dial tone detection */
 
 #define DSP_FAXMODE_DETECT_CNG	(1 << 0)
 #define DSP_FAXMODE_DETECT_CED	(1 << 1)
Index: main/dsp.c
===================================================================
--- main/dsp.c	(revision 113646)
+++ main/dsp.c	(working copy)
@@ -82,7 +82,9 @@
 	HZ_425 = 0,
 
 	/*! For UK mode */
-	HZ_400 = 0
+	HZ_350UK = 0,
+	HZ_400UK,
+	HZ_440UK
 };
 
 static struct progalias {
@@ -102,7 +104,7 @@
 } modes[] = {
 	{ GSAMP_SIZE_NA, { 350, 440, 480, 620, 950, 1400, 1800 } },	/*!< North America */
 	{ GSAMP_SIZE_CR, { 425 } },                                	/*!< Costa Rica, Brazil */
-	{ GSAMP_SIZE_UK, { 400 } },                                	/*!< UK */
+	{ GSAMP_SIZE_UK, { 350, 400, 440 } },                                	/*!< UK */
 };
 
 #define DEFAULT_THRESHOLD	512
@@ -993,8 +995,10 @@
 					newstate = DSP_TONE_STATE_SILENCE;
 				break;
 			case PROG_MODE_UK:
-				if (hz[HZ_400] > TONE_MIN_THRESH * TONE_THRESH) {
+				if (hz[HZ_400UK] > TONE_MIN_THRESH * TONE_THRESH) {
 					newstate = DSP_TONE_STATE_HUNGUP;
+				} else if (pair_there(hz[HZ_350UK], hz[HZ_440UK], hz[HZ_400UK], hz[HZ_400UK], dsp->genergy)) {
+					newstate = DSP_TONE_STATE_DIALTONE;
 				}
 				break;
 			default:
@@ -1399,7 +1403,8 @@
 				ast_log(LOG_WARNING, "Don't know how to represent call progress message %d\n", res);
 			}
 		}
-	}
+	} else if ((dsp->features & DSP_FEATURE_WAITDIALTONE))
+		res = __ast_dsp_call_progress(dsp, shortdata, len);
 
 done:
 	/* Mute fragment of the frame */