bridging code cleanups:

	code style, formatting
	use enum/symbolic constants for return codes
	efficiency improvements
	(zaptel) only disable DTMF detection once per bridge, not every frame
	(zaptel) ensure VPM DTMF detector is turned off during native bridge


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@6312 f38db490-d61c-443f-a65b-d21fe96a405b

6 files changed, 353 insertions, 320 deletions

diff --git a/channel.c b/channel.c
index ee076ee3b..e8b72b3a6 100755
--- a/channel.c
+++ b/channel.c
@@ -2874,19 +2874,21 @@ static void bridge_playfile(struct ast_channel *chan, struct ast_channel *peer,
 	check = ast_autoservice_stop(peer);
 }
 
-static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel *c0, struct ast_channel *c1, struct ast_bridge_config *config, struct ast_frame **fo, struct ast_channel **rc)
+static enum ast_bridge_result ast_generic_bridge(int *playitagain, int *playit, struct ast_channel *c0, struct ast_channel *c1,
+			      struct ast_bridge_config *config, struct ast_frame **fo, struct ast_channel **rc)
 {
-	/* Copy voice back and forth between the two channels.	Give the peer
-	   the ability to transfer calls with '#<extension' syntax. */
+	/* Copy voice back and forth between the two channels. */
 	struct ast_channel *cs[3];
 	int to;
 	struct ast_frame *f;
 	struct ast_channel *who = NULL;
 	void *pvt0, *pvt1;
-	int res=0;
+	enum ast_bridge_result res = AST_BRIDGE_COMPLETE;
 	int o0nativeformats;
 	int o1nativeformats;
 	long elapsed_ms=0, time_left_ms=0;
+	int watch_c0_dtmf;
+	int watch_c1_dtmf;
 	
 	cs[0] = c0;
 	cs[1] = c1;
@@ -2894,12 +2896,15 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
 	pvt1 = c1->pvt;
 	o0nativeformats = c0->nativeformats;
 	o1nativeformats = c1->nativeformats;
+	watch_c0_dtmf = config->flags & AST_BRIDGE_DTMF_CHANNEL_0;
+	watch_c1_dtmf = config->flags & AST_BRIDGE_DTMF_CHANNEL_1;
 
 	for (;;) {
-		if ((c0->pvt != pvt0) || (c1->pvt != pvt1) || (o0nativeformats != c0->nativeformats) ||
-			(o1nativeformats != c1->nativeformats)) {
+		if ((c0->pvt != pvt0) || (c1->pvt != pvt1) ||
+		    (o0nativeformats != c0->nativeformats) ||
+		    (o1nativeformats != c1->nativeformats)) {
 			/* Check for Masquerade, codec changes, etc */
-			res = -3;
+			res = AST_BRIDGE_RETRY;
 			break;
 		}
 		/* timestamp */
@@ -2908,25 +2913,27 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
 			elapsed_ms = ast_tvdiff_ms(ast_tvnow(), config->start_time);
 			time_left_ms = config->timelimit - elapsed_ms;
 
-			if (*playitagain && ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) || (ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING))) && (config->play_warning && time_left_ms <= config->play_warning)) { 
+			if (*playitagain &&
+			    ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) ||
+			     (ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING))) &&
+			    (config->play_warning && time_left_ms <= config->play_warning)) { 
 				if (config->warning_freq == 0 || time_left_ms == config->play_warning || (time_left_ms % config->warning_freq) <= 50) {
-					res = -3;
+					res = AST_BRIDGE_RETRY;
 					break;
 				}
 			}
 			if (time_left_ms <= 0) {
-				res = -3;
+				res = AST_BRIDGE_RETRY;
 				break;
 			}
 			if (time_left_ms >= 5000 && *playit) {
-				res = -3;
+				res = AST_BRIDGE_RETRY;
 				break;
 			}
 			to = time_left_ms;
 		} else	
 			to = -1;
 
-
 		who = ast_waitfor_n(cs, 2, &to);
 		if (!who) {
 			ast_log(LOG_DEBUG, "Nobody there, continuing...\n"); 
@@ -2937,7 +2944,6 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
                 			c1->_softhangup = 0;
 				c0->_bridge = c1;
 				c1->_bridge = c0;
-				continue;
 			}
 			continue;
 		}
@@ -2945,7 +2951,7 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
 		if (!f) {
 			*fo = NULL;
 			*rc = who;
-			res = 0;
+			res = AST_BRIDGE_COMPLETE;
 			ast_log(LOG_DEBUG, "Didn't get a frame from channel: %s\n",who->name);
 			break;
 		}
@@ -2956,40 +2962,27 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
 			} else {
 				*fo = f;
 				*rc = who;
-				res =  0;
+				res =  AST_BRIDGE_COMPLETE;
 				ast_log(LOG_DEBUG, "Got a FRAME_CONTROL (%d) frame on channel %s\n", f->subclass, who->name);
 				break;
 			}
 		}
 		if ((f->frametype == AST_FRAME_VOICE) ||
-			(f->frametype == AST_FRAME_TEXT) ||
-			(f->frametype == AST_FRAME_VIDEO) || 
-			(f->frametype == AST_FRAME_IMAGE) ||
-			(f->frametype == AST_FRAME_HTML) ||
-			(f->frametype == AST_FRAME_DTMF)) {
-
-			if ((f->frametype == AST_FRAME_DTMF) && 
-				(config->flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))) {
-				if ((who == c0)) {
-					if  ((config->flags & AST_BRIDGE_DTMF_CHANNEL_0)) {
-						*rc = c0;
-						*fo = f;
-						/* Take out of conference mode */
-						res = 0;
-						ast_log(LOG_DEBUG, "Got AST_BRIDGE_DTMF_CHANNEL_0 on c0 (%s)\n",c0->name);
-						break;
-					} else 
-						goto tackygoto;
-				} else
-				if ((who == c1)) {
-					if (config->flags & AST_BRIDGE_DTMF_CHANNEL_1) {
-						*rc = c1;
-						*fo = f;
-						res =  0;
-						ast_log(LOG_DEBUG, "Got AST_BRIDGE_DTMF_CHANNEL_1 on c1 (%s)\n",c1->name);
-						break;
-					} else
-						goto tackygoto;
+		    (f->frametype == AST_FRAME_DTMF) ||
+		    (f->frametype == AST_FRAME_VIDEO) || 
+		    (f->frametype == AST_FRAME_IMAGE) ||
+		    (f->frametype == AST_FRAME_HTML) ||
+		    (f->frametype == AST_FRAME_TEXT)) {
+			if (f->frametype == AST_FRAME_DTMF) {
+				if (((who == c0) && watch_c0_dtmf) ||
+				    ((who == c1) && watch_c1_dtmf)) {
+					*rc = who;
+					*fo = f;
+					res = AST_BRIDGE_COMPLETE;
+					ast_log(LOG_DEBUG, "Got DTMF on channel (%s)\n", who->name);
+					break;
+				} else {
+					goto tackygoto;
 				}
 			} else {
 #if 0
@@ -2999,12 +2992,7 @@ static int ast_generic_bridge(int *playitagain, int *playit, struct ast_channel
 				last = who;
 #endif
 tackygoto:
-				/* Don't copy packets if there is a generator on either one, since they're
-				   not supposed to be listening anyway */
-				if (who == c0) 
-					ast_write(c1, f);
-				else 
-					ast_write(c0, f);
+				ast_write((who == c0) ? c1 : c0, f);
 			}
 		}
 		ast_frfree(f);
@@ -3018,37 +3006,20 @@ tackygoto:
 }
 
 /*--- ast_channel_bridge: Bridge two channels together */
-int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, struct ast_bridge_config *config, struct ast_frame **fo, struct ast_channel **rc) 
+enum ast_bridge_result ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1,
+					  struct ast_bridge_config *config, struct ast_frame **fo, struct ast_channel **rc) 
 {
-	/* Copy voice back and forth between the two channels.	Give the peer
-	   the ability to transfer calls with '#<extension' syntax. */
-	struct ast_channel *cs[3];
 	struct ast_channel *who = NULL;
-	int res=0;
+	enum ast_bridge_result res = AST_BRIDGE_COMPLETE;
 	int nativefailed=0;
 	int firstpass;
 	int o0nativeformats;
 	int o1nativeformats;
 	long elapsed_ms=0, time_left_ms=0;
 	int playit=0, playitagain=1, first_time=1;
+	char caller_warning = 0;
+	char callee_warning = 0;
 
-	*fo = NULL;
-	firstpass = config->firstpass;
-	config->firstpass = 0;
-
-	/* timestamp */
-	if (! (config->start_time.tv_sec && config->start_time.tv_usec))
-		config->start_time = ast_tvnow();
-	time_left_ms = config->timelimit;
-
-	if ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) && config->start_sound && firstpass)
-		bridge_playfile(c0,c1,config->start_sound,time_left_ms / 1000);
-	if ((ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING)) && config->start_sound && firstpass)
-		bridge_playfile(c1,c0,config->start_sound,time_left_ms / 1000);
-
-	/* Stop if we're a zombie or need a soft hangup */
-	if (ast_test_flag(c0, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c0) || ast_test_flag(c1, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c1)) 
-		return -1;
 	if (c0->_bridge) {
 		ast_log(LOG_WARNING, "%s is already in a bridge with %s\n", 
 			c0->name, c0->_bridge->name);
@@ -3060,49 +3031,68 @@ int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, struct as
 		return -1;
 	}
 	
+	/* Stop if we're a zombie or need a soft hangup */
+	if (ast_test_flag(c0, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c0) ||
+	    ast_test_flag(c1, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c1)) 
+		return -1;
+
+	*fo = NULL;
+	firstpass = config->firstpass;
+	config->firstpass = 0;
+
+	if (ast_tvzero(config->start_time))
+		config->start_time = ast_tvnow();
+	time_left_ms = config->timelimit;
+
+	caller_warning = ast_test_flag(&config->features_caller, AST_FEATURE_PLAY_WARNING);
+	callee_warning = ast_test_flag(&config->features_callee, AST_FEATURE_PLAY_WARNING);
+
+	if (config->start_sound && firstpass) {
+		if (caller_warning)
+			bridge_playfile(c0, c1, config->start_sound, time_left_ms / 1000);
+		if (callee_warning)
+			bridge_playfile(c1, c0, config->start_sound, time_left_ms / 1000);
+	}
+
 	/* Keep track of bridge */
 	c0->_bridge = c1;
 	c1->_bridge = c0;
-	cs[0] = c0;
-	cs[1] = c1;
 	
 	manager_event(EVENT_FLAG_CALL, "Link", 
-			"Channel1: %s\r\n"
-			"Channel2: %s\r\n"
-			"Uniqueid1: %s\r\n"
-			"Uniqueid2: %s\r\n"
-                        "CallerID1: %s\r\n"
-			"CallerID2: %s\r\n",
-			c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
+		      "Channel1: %s\r\n"
+		      "Channel2: %s\r\n"
+		      "Uniqueid1: %s\r\n"
+		      "Uniqueid2: %s\r\n"
+		      "CallerID1: %s\r\n"
+		      "CallerID2: %s\r\n",
+		      c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
                                                                         
-	o1nativeformats = c1->nativeformats;
 	o0nativeformats = c0->nativeformats;
+	o1nativeformats = c1->nativeformats;
+
 	for (/* ever */;;) {
-		/* timestamp */
 		if (config->timelimit) {
 			elapsed_ms = ast_tvdiff_ms(ast_tvnow(), config->start_time);
 			time_left_ms = config->timelimit - elapsed_ms;
 
-			if (playitagain && ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) || (ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING))) && (config->play_warning && time_left_ms <= config->play_warning)) { 
+			if (playitagain && (caller_warning || callee_warning) && (config->play_warning && time_left_ms <= config->play_warning)) { 
 				/* narrowing down to the end */
 				if (config->warning_freq == 0) {
 					playit = 1;
-					first_time=0;
-					playitagain=0;
+					first_time = 0;
+					playitagain = 0;
 				} else if (first_time) {
 					playit = 1;
-					first_time=0;
-				} else {
-					if ((time_left_ms % config->warning_freq) <= 50) {
-						playit = 1;
-					}
+					first_time = 0;
+				} else if ((time_left_ms % config->warning_freq) <= 50) {
+					playit = 1;
 				}
 			}
 			if (time_left_ms <= 0) {
-				if ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) && config->end_sound)
-					bridge_playfile(c0,c1,config->end_sound,0);
-				if ((ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING)) && config->end_sound)
-					bridge_playfile(c1,c0,config->end_sound,0);
+				if (caller_warning && config->end_sound)
+					bridge_playfile(c0, c1, config->end_sound, 0);
+				if (callee_warning && config->end_sound)
+					bridge_playfile(c1, c0, config->end_sound, 0);
 				*fo = NULL;
 				if (who) 
 					*rc = who;
@@ -3110,13 +3100,12 @@ int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, struct as
 				break;
 			}
 			if (time_left_ms >= 5000 && playit) {
-				if ((ast_test_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING)) && config->warning_sound && config->play_warning)
-					bridge_playfile(c0,c1,config->warning_sound,time_left_ms / 1000);
-				if ((ast_test_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING)) && config->warning_sound && config->play_warning)
-					bridge_playfile(c1,c0,config->warning_sound,time_left_ms / 1000);
+				if (caller_warning && config->warning_sound && config->play_warning)
+					bridge_playfile(c0, c1, config->warning_sound, time_left_ms / 1000);
+				if (callee_warning && config->warning_sound && config->play_warning)
+					bridge_playfile(c1, c0, config->warning_sound, time_left_ms / 1000);
 				playit = 0;
 			}
-			
 		}
 
 		if (c0->_softhangup == AST_SOFTHANGUP_UNBRIDGE || c1->_softhangup == AST_SOFTHANGUP_UNBRIDGE) {
@@ -3131,87 +3120,105 @@ int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, struct as
 		}
 		
 		/* Stop if we're a zombie or need a soft hangup */
-		if (ast_test_flag(c0, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c0) || ast_test_flag(c1, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c1)) {
+		if (ast_test_flag(c0, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c0) ||
+		    ast_test_flag(c1, AST_FLAG_ZOMBIE) || ast_check_hangup_locked(c1)) {
 			*fo = NULL;
 			if (who)
 				*rc = who;
 			res = 0;
-			ast_log(LOG_DEBUG, "Bridge stops because we're zombie or need a soft hangup: c0=%s, c1=%s, flags: %s,%s,%s,%s\n",c0->name,c1->name,ast_test_flag(c0, AST_FLAG_ZOMBIE)?"Yes":"No",ast_check_hangup(c0)?"Yes":"No",ast_test_flag(c1, AST_FLAG_ZOMBIE)?"Yes":"No",ast_check_hangup(c1)?"Yes":"No");
+			ast_log(LOG_DEBUG, "Bridge stops because we're zombie or need a soft hangup: c0=%s, c1=%s, flags: %s,%s,%s,%s\n",
+				c0->name, c1->name,
+				ast_test_flag(c0, AST_FLAG_ZOMBIE) ? "Yes" : "No",
+				ast_check_hangup(c0) ? "Yes" : "No",
+				ast_test_flag(c1, AST_FLAG_ZOMBIE) ? "Yes" : "No",
+				ast_check_hangup(c1) ? "Yes" : "No");
 			break;
 		}
-		if (c0->tech->bridge && config->timelimit==0 &&
-			(c0->tech->bridge == c1->tech->bridge) && !nativefailed && !c0->monitor && !c1->monitor && !c0->spiers && !c1->spiers) {
-				/* Looks like they share a bridge code */
+
+		if (c0->tech->bridge &&
+		    (config->timelimit == 0) &&
+		    (c0->tech->bridge == c1->tech->bridge) &&
+		    !nativefailed && !c0->monitor && !c1->monitor && !c0->spiers && !c1->spiers) {
+			/* Looks like they share a bridge method */
 			if (option_verbose > 2) 
 				ast_verbose(VERBOSE_PREFIX_3 "Attempting native bridge of %s and %s\n", c0->name, c1->name);
 			ast_set_flag(c0, AST_FLAG_NBRIDGE);
 			ast_set_flag(c1, AST_FLAG_NBRIDGE);
-			if (!(res = c0->tech->bridge(c0, c1, config->flags, fo, rc))) {
-				c0->_bridge = NULL;
-				c1->_bridge = NULL;
+			if ((res = c0->tech->bridge(c0, c1, config->flags, fo, rc)) == AST_BRIDGE_COMPLETE) {
 				manager_event(EVENT_FLAG_CALL, "Unlink", 
-					"Channel1: %s\r\n"
-					"Channel2: %s\r\n"
-					"Uniqueid1: %s\r\n"
-					"Uniqueid2: %s\r\n"
-                                        "CallerID1: %s\r\n"
-                                        "CallerID2: %s\r\n",
-					c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
-				ast_log(LOG_DEBUG, "Returning from native bridge, channels: %s, %s\n",c0->name ,c1->name);
+					      "Channel1: %s\r\n"
+					      "Channel2: %s\r\n"
+					      "Uniqueid1: %s\r\n"
+					      "Uniqueid2: %s\r\n"
+					      "CallerID1: %s\r\n"
+					      "CallerID2: %s\r\n",
+					      c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
+				ast_log(LOG_DEBUG, "Returning from native bridge, channels: %s, %s\n", c0->name, c1->name);
+
 				ast_clear_flag(c0, AST_FLAG_NBRIDGE);
 				ast_clear_flag(c1, AST_FLAG_NBRIDGE);
-				if (c0->_softhangup == AST_SOFTHANGUP_UNBRIDGE || c1->_softhangup == AST_SOFTHANGUP_UNBRIDGE) {
-					c0->_bridge = c1;
-					c1->_bridge = c0;
+
+				if (c0->_softhangup == AST_SOFTHANGUP_UNBRIDGE || c1->_softhangup == AST_SOFTHANGUP_UNBRIDGE)
 					continue;
-				}
-				else 
-				return 0;
+
+				c0->_bridge = NULL;
+				c1->_bridge = NULL;
+
+				return res;
 			} else {
 				ast_clear_flag(c0, AST_FLAG_NBRIDGE);
 				ast_clear_flag(c1, AST_FLAG_NBRIDGE);
 			}
 			
-			/* If they return non-zero then continue on normally.  Let "-2" mean don't worry about
-			   my not wanting to bridge */
-			if ((res != -2) && (res != -3))
+			switch (res) {
+			case AST_BRIDGE_RETRY:
+				continue;
+			default:
 				ast_log(LOG_WARNING, "Private bridge between %s and %s failed\n", c0->name, c1->name);
-			if (res != -3)
+				/* fallthrough */
+			case AST_BRIDGE_FAILED_NOWARN:
 				nativefailed++;
+				break;
+			}
 		}
 	
-		if (((c0->writeformat != c1->readformat) || (c0->readformat != c1->writeformat) || (c0->nativeformats != o0nativeformats) || (c1->nativeformats != o1nativeformats)) &&
-			!(c0->generator || c1->generator))  {
+		if (((c0->writeformat != c1->readformat) || (c0->readformat != c1->writeformat) ||
+		    (c0->nativeformats != o0nativeformats) || (c1->nativeformats != o1nativeformats)) &&
+		    !(c0->generator || c1->generator)) {
 			if (ast_channel_make_compatible(c0, c1)) {
 				ast_log(LOG_WARNING, "Can't make %s and %s compatible\n", c0->name, c1->name);
                                 manager_event(EVENT_FLAG_CALL, "Unlink",
-                                        "Channel1: %s\r\n"
-                                        "Channel2: %s\r\n"
-                                        "Uniqueid1: %s\r\n"
-                                        "Uniqueid2: %s\r\n"
-                                        "CallerID1: %s\r\n"
-                                        "CallerID2: %s\r\n",
-                                        c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
-				return -1;
+					      "Channel1: %s\r\n"
+					      "Channel2: %s\r\n"
+					      "Uniqueid1: %s\r\n"
+					      "Uniqueid2: %s\r\n"
+					      "CallerID1: %s\r\n"
+					      "CallerID2: %s\r\n",
+					      c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
+				return AST_BRIDGE_FAILED;
 			}
 			o0nativeformats = c0->nativeformats;
 			o1nativeformats = c1->nativeformats;
 		}
+
 		res = ast_generic_bridge(&playitagain, &playit, c0, c1, config, fo, rc);
-		if (res != -3)
+		if (res != AST_BRIDGE_RETRY)
 			break;
 	}
+
 	c0->_bridge = NULL;
 	c1->_bridge = NULL;
+
 	manager_event(EVENT_FLAG_CALL, "Unlink",
-					"Channel1: %s\r\n"
-					"Channel2: %s\r\n"
-					"Uniqueid1: %s\r\n"
-					"Uniqueid2: %s\r\n"
-					"CallerID1: %s\r\n"
-					"CallerID2: %s\r\n",
-					c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
-	ast_log(LOG_DEBUG, "Bridge stops bridging channels %s and %s\n",c0->name,c1->name);
+		      "Channel1: %s\r\n"
+		      "Channel2: %s\r\n"
+		      "Uniqueid1: %s\r\n"
+		      "Uniqueid2: %s\r\n"
+		      "CallerID1: %s\r\n"
+		      "CallerID2: %s\r\n",
+		      c0->name, c1->name, c0->uniqueid, c1->uniqueid, c0->cid.cid_num, c1->cid.cid_num);
+	ast_log(LOG_DEBUG, "Bridge stops bridging channels %s and %s\n", c0->name, c1->name);
+
 	return res;
 }
 
diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index cfa62bb54..9c12b29f5 100755
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -708,7 +708,7 @@ static struct ast_frame *iax2_read(struct ast_channel *c);
 static int iax2_write(struct ast_channel *c, struct ast_frame *f);
 static int iax2_indicate(struct ast_channel *c, int condition);
 static int iax2_setoption(struct ast_channel *c, int option, void *data, int datalen);
-static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
+static enum ast_bridge_result iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
 static int iax2_transfer(struct ast_channel *c, const char *dest);
 static int iax2_fixup(struct ast_channel *oldchannel, struct ast_channel *newchan);
 
@@ -3050,7 +3050,7 @@ static void unlock_both(unsigned short callno0, unsigned short callno1)
 	ast_mutex_unlock(&iaxsl[callno0]);
 }
 
-static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
+static enum ast_bridge_result iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
 {
 	struct ast_channel *cs[3];
 	struct ast_channel *who;
@@ -3089,7 +3089,7 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 				iaxs[callno1]->bridgecallno = 0;
 				ast_mutex_unlock(&iaxsl[callno1]);
 			}
-			return -2;
+			return AST_BRIDGE_FAILED_NOWARN;
 		}
 		if (c0->nativeformats != c1->nativeformats) {
 			if (option_verbose > 2) {
@@ -3104,7 +3104,7 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 			iaxs[callno0]->bridgecallno = 0;
 			iaxs[callno1]->bridgecallno = 0;
 			unlock_both(callno0, callno1);
-			return -2;
+			return AST_BRIDGE_FAILED_NOWARN;
 		}
 		/* check if transfered and if we really want native bridging */
 		if (!transferstarted && !ast_test_flag(iaxs[callno0], IAX_NOTRANSFER) && !ast_test_flag(iaxs[callno1], IAX_NOTRANSFER) && 
@@ -3124,7 +3124,7 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 				c1->_softhangup |= AST_SOFTHANGUP_DEV;
 				*fo = NULL;
 				*rc = c0;
-				res = 0;
+				res = AST_BRIDGE_COMPLETE;
 				break;
 			}
 		}
@@ -3132,7 +3132,7 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 		who = ast_waitfor_n(cs, 2, &to);
 		if (!who) {
 			if (ast_check_hangup(c0) || ast_check_hangup(c1)) {
-				res = -1;
+				res = AST_BRIDGE_FAILED;
 				break;
 			}
 			continue;
@@ -3141,28 +3141,27 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 		if (!f) {
 			*fo = NULL;
 			*rc = who;
-			res = 0;
+			res = AST_BRIDGE_COMPLETE;
 			break;
 		}
 		if ((f->frametype == AST_FRAME_CONTROL) && !(flags & AST_BRIDGE_IGNORE_SIGS)) {
 			*fo = f;
 			*rc = who;
-			res =  0;
+			res =  AST_BRIDGE_COMPLETE;
 			break;
 		}
 		if ((f->frametype == AST_FRAME_VOICE) ||
-			(f->frametype == AST_FRAME_TEXT) ||
-			(f->frametype == AST_FRAME_VIDEO) || 
-			(f->frametype == AST_FRAME_IMAGE) ||
-			(f->frametype == AST_FRAME_DTMF)) {
+		    (f->frametype == AST_FRAME_TEXT) ||
+		    (f->frametype == AST_FRAME_VIDEO) || 
+		    (f->frametype == AST_FRAME_IMAGE) ||
+		    (f->frametype == AST_FRAME_DTMF)) {
 			if ((f->frametype == AST_FRAME_DTMF) && 
-				(flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))) {
+			    (flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))) {
 				if ((who == c0)) {
 					if  ((flags & AST_BRIDGE_DTMF_CHANNEL_0)) {
 						*rc = c0;
 						*fo = f;
-						/* Take out of conference mode */
-						res = 0;
+						res = AST_BRIDGE_COMPLETE;
 						/* Remove from native mode */
 						break;
 					} else 
@@ -3172,8 +3171,7 @@ static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 					if (flags & AST_BRIDGE_DTMF_CHANNEL_1) {
 						*rc = c1;
 						*fo = f;
-						res =  0;
-						/* Remove from native mode */
+						res =  AST_BRIDGE_COMPLETE;
 						break;
 					} else
 						goto tackygoto;
diff --git a/channels/chan_vpb.c b/channels/chan_vpb.c
index 6289629eb..be6004992 100755
--- a/channels/chan_vpb.c
+++ b/channels/chan_vpb.c
@@ -326,7 +326,7 @@ static int vpb_hangup(struct ast_channel *ast);
 static int vpb_answer(struct ast_channel *ast);
 static struct ast_frame *vpb_read(struct ast_channel *ast);
 static int vpb_write(struct ast_channel *ast, struct ast_frame *frame);
-static int vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
+static enum ast_bridge_result vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
 static int vpb_indicate(struct ast_channel *ast, int condition);
 static int vpb_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
 
@@ -396,11 +396,12 @@ static struct ast_channel_tech vpb_tech_indicate = {
 /* #define HALF_DUPLEX_BRIDGE */
 
 /* This is the Native bridge code, which Asterisk will try before using its own bridging code */
-static int vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
+static enum ast_bridge_result vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
 {
 	struct vpb_pvt *p0 = (struct vpb_pvt *)c0->tech_pvt;
 	struct vpb_pvt *p1 = (struct vpb_pvt *)c1->tech_pvt;
-	int i, res;
+	int i;
+	enum ast_bridge_result res;
 
 	struct ast_channel *cs[3];
 	struct ast_channel *who;
@@ -412,10 +413,10 @@ static int vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 
 	#ifdef BAD_V4PCI_BRIDGE
 	if(p0->vpb_model==vpb_model_v4pci)
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 	#endif
 	if ( UseNativeBridge != 1){
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 	}
 
 /*
@@ -444,7 +445,7 @@ static int vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 		ast_log(LOG_WARNING, "%s: vpb_bridge: Failed to bridge %s and %s!\n", p0->dev, c0->name, c1->name);
 		ast_mutex_unlock(&p0->lock);
 		ast_mutex_unlock(&p1->lock);
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 	} else {
 		/* Set bridge pointers. You don't want to take these locks while holding bridge lock.*/
 		ast_mutex_lock(&p0->lock); {
@@ -581,7 +582,7 @@ static int vpb_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 	ast_mutex_unlock(&p0->lock);
 	ast_mutex_unlock(&p1->lock);
 */
-	return (res==VPB_OK)?0:-1;
+	return (res==VPB_OK) ? AST_BRIDGE_COMPLETE : AST_BRIDGE_FAILED;
 }
 
 /* Caller ID can be located in different positions between the rings depending on your Telco
diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index 0874a3118..b352a1fa6 100755
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -323,7 +323,7 @@ static pthread_t monitor_thread = AST_PTHREADT_NULL;
 
 static int restart_monitor(void);
 
-static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
+static enum ast_bridge_result zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
 
 static int zt_sendtext(struct ast_channel *c, const char *text);
 
@@ -664,7 +664,6 @@ static int zt_hangup(struct ast_channel *ast);
 static int zt_answer(struct ast_channel *ast);
 struct ast_frame *zt_read(struct ast_channel *ast);
 static int zt_write(struct ast_channel *ast, struct ast_frame *frame);
-static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
 struct ast_frame *zt_exception(struct ast_channel *ast);
 static int zt_indicate(struct ast_channel *chan, int condition);
 static int zt_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
@@ -2775,29 +2774,59 @@ static void zt_link(struct zt_pvt *slave, struct zt_pvt *master) {
 	ast_log(LOG_DEBUG, "Making %d slave to master %d at %d\n", slave->channel, master->channel, x);
 }
 
-static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
+static void disable_dtmf_detect(struct zt_pvt *p)
 {
-	struct ast_channel *who = NULL, *cs[3];
+	int val;
+
+	p->ignoredtmf = 1;
+
+#ifdef ZT_TONEDETECT
+	val = 0;
+	ioctl(p->subs[SUB_REAL].zfd, ZT_TONEDETECT, &val);
+#endif		
+	
+}
+
+static void enable_dtmf_detect(struct zt_pvt *p)
+{
+	int val;
+
+	p->ignoredtmf = 0;
+
+#ifdef ZT_TONEDETECT
+	val = ZT_TONEDETECT_ON | ZT_TONEDETECT_MUTE;
+	ioctl(p->subs[SUB_REAL].zfd, ZT_TONEDETECT, &val);
+#endif		
+}
+
+static enum ast_bridge_result zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
+{
+	struct ast_channel *who;
 	struct zt_pvt *p0, *p1, *op0, *op1;
-	struct zt_pvt *master=NULL, *slave=NULL;
+	struct zt_pvt *master = NULL, *slave = NULL;
 	struct ast_frame *f;
 	int to;
 	int inconf = 0;
-	int nothingok = 0;
-	int ofd1, ofd2;
-	int oi1, oi2, i1 = -1, i2 = -1, t1, t2;
-	int os1 = -1, os2 = -1;
-	struct ast_channel *oc1, *oc2;
+	int nothingok = 1;
+	int ofd0, ofd1;
+	int oi0, oi1, i0 = -1, i1 = -1, t0, t1;
+	int os0 = -1, os1 = -1;
+	struct ast_channel *oc0, *oc1;
+	enum ast_bridge_result res;
+
 #ifdef PRI_2BCT
 	int triedtopribridge = 0;
 	q931_call *q931c0 = NULL, *q931c1 = NULL;
 #endif
 
+	/* For now, don't attempt to native bridge if either channel needs DTMF detection.
+	   There is code below to handle it properly until DTMF is actually seen,
+	   but due to currently unresolved issues it's ignored...
+	*/
 
-	/* if need DTMF, cant native bridge */
 	if (flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))
-		return -2;
-		
+		return AST_BRIDGE_FAILED_NOWARN;
+
 	ast_mutex_lock(&c0->lock);
 	ast_mutex_lock(&c1->lock);
 
@@ -2807,24 +2836,23 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 	if (!p0 || (!p0->sig) || !p1 || (!p1->sig)) {
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 	}
 
-	op0 = p0 = c0->tech_pvt;
-	op1 = p1 = c1->tech_pvt;
-	ofd1 = c0->fds[0];
-	ofd2 = c1->fds[0];
-	oi1 = zt_get_index(c0, p0, 0);
-	oi2 = zt_get_index(c1, p1, 0);
-	oc1 = p0->owner;
-	oc2 = p1->owner;
-	if ((oi1 < 0) || (oi2 < 0)) {
+	oi0 = zt_get_index(c0, p0, 0);
+	oi1 = zt_get_index(c1, p1, 0);
+	if ((oi0 < 0) || (oi1 < 0)) {
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		return -1;
+		return AST_BRIDGE_FAILED;
 	}
 
-
+	op0 = p0 = c0->tech_pvt;
+	op1 = p1 = c1->tech_pvt;
+	ofd0 = c0->fds[0];
+	ofd1 = c1->fds[0];
+	oc0 = p0->owner;
+	oc1 = p1->owner;
 
 	ast_mutex_lock(&p0->lock);
 	if (ast_mutex_trylock(&p1->lock)) {
@@ -2833,13 +2861,11 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
 		ast_log(LOG_NOTICE, "Avoiding deadlock...\n");
-		return -3;
+		return AST_BRIDGE_RETRY;
 	}
-	if ((oi1 == SUB_REAL) && (oi2 == SUB_REAL)) {
-		if (!p0->owner || !p1->owner) {
-			/* Currently unowned -- Do nothing.  */
-			nothingok = 1;
-		} else {
+
+	if ((oi0 == SUB_REAL) && (oi1 == SUB_REAL)) {
+		if (p0->owner && p1->owner) {
 			/* If we don't have a call-wait in a 3-way, and we aren't in a 3-way, we can be master */
 			if (!p0->subs[SUB_CALLWAIT].inthreeway && !p1->subs[SUB_REAL].inthreeway) {
 				master = p0;
@@ -2851,40 +2877,41 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 				inconf = 1;
 			} else {
 				ast_log(LOG_WARNING, "Huh?  Both calls are callwaits or 3-ways?  That's clever...?\n");
-				ast_log(LOG_WARNING, "p0: chan %d/%d/CW%d/3W%d, p1: chan %d/%d/CW%d/3W%d\n", p0->channel, oi1, (p0->subs[SUB_CALLWAIT].zfd > -1) ? 1 : 0, p0->subs[SUB_REAL].inthreeway,
-						p0->channel, oi1, (p1->subs[SUB_CALLWAIT].zfd > -1) ? 1 : 0, p1->subs[SUB_REAL].inthreeway);
+				ast_log(LOG_WARNING, "p0: chan %d/%d/CW%d/3W%d, p1: chan %d/%d/CW%d/3W%d\n",
+					p0->channel,
+					oi0, (p0->subs[SUB_CALLWAIT].zfd > -1) ? 1 : 0,
+					p0->subs[SUB_REAL].inthreeway, p0->channel,
+					oi0, (p1->subs[SUB_CALLWAIT].zfd > -1) ? 1 : 0,
+					p1->subs[SUB_REAL].inthreeway);
 			}
+			nothingok = 0;
 		}
-	} else if ((oi1 == SUB_REAL) && (oi2 == SUB_THREEWAY)) {
+	} else if ((oi0 == SUB_REAL) && (oi1 == SUB_THREEWAY)) {
 		if (p1->subs[SUB_THREEWAY].inthreeway) {
 			master = p1;
 			slave = p0;
-		} else {
-			nothingok = 1;
+			nothingok = 0;
 		}
-	} else if ((oi1 == SUB_THREEWAY) && (oi2 == SUB_REAL)) {
+	} else if ((oi0 == SUB_THREEWAY) && (oi1 == SUB_REAL)) {
 		if (p0->subs[SUB_THREEWAY].inthreeway) {
 			master = p0;
 			slave = p1;
-		} else {
-			nothingok  = 1;
+			nothingok = 0;
 		}
-	} else if ((oi1 == SUB_REAL) && (oi2 == SUB_CALLWAIT)) {
+	} else if ((oi0 == SUB_REAL) && (oi1 == SUB_CALLWAIT)) {
 		/* We have a real and a call wait.  If we're in a three way call, put us in it, otherwise, 
 		   don't put us in anything */
 		if (p1->subs[SUB_CALLWAIT].inthreeway) {
 			master = p1;
 			slave = p0;
-		} else {
-			nothingok = 1;
+			nothingok = 0;
 		}
-	} else if ((oi1 == SUB_CALLWAIT) && (oi2 == SUB_REAL)) {
+	} else if ((oi0 == SUB_CALLWAIT) && (oi1 == SUB_REAL)) {
 		/* Same as previous */
 		if (p0->subs[SUB_CALLWAIT].inthreeway) {
 			master = p0;
 			slave = p1;
-		} else {
-			nothingok = 1;
+			nothingok = 0;
 		}
 	}
 	ast_log(LOG_DEBUG, "master: %d, slave: %d, nothingok: %d\n",
@@ -2893,31 +2920,31 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 		/* Stop any tones, or play ringtone as appropriate.  If they're bridged
 		   in an active threeway call with a channel that is ringing, we should
 		   indicate ringing. */
-		if ((oi2 == SUB_THREEWAY) && 
-			p1->subs[SUB_THREEWAY].inthreeway && 
-			p1->subs[SUB_REAL].owner && 
-			p1->subs[SUB_REAL].inthreeway && 
-			(p1->subs[SUB_REAL].owner->_state == AST_STATE_RINGING)) {
-				ast_log(LOG_DEBUG, "Playing ringback on %s since %s is in a ringing three-way\n", c0->name, c1->name);
-				tone_zone_play_tone(p0->subs[oi1].zfd, ZT_TONE_RINGTONE);
-				os2 = p1->subs[SUB_REAL].owner->_state;
-		} else {
-				ast_log(LOG_DEBUG, "Stoping tones on %d/%d talking to %d/%d\n", p0->channel, oi1, p1->channel, oi2);
-				tone_zone_play_tone(p0->subs[oi1].zfd, -1);
-		}
 		if ((oi1 == SUB_THREEWAY) && 
-			p0->subs[SUB_THREEWAY].inthreeway && 
-			p0->subs[SUB_REAL].owner && 
-			p0->subs[SUB_REAL].inthreeway && 
-			(p0->subs[SUB_REAL].owner->_state == AST_STATE_RINGING)) {
-				ast_log(LOG_DEBUG, "Playing ringback on %s since %s is in a ringing three-way\n", c1->name, c0->name);
-				tone_zone_play_tone(p1->subs[oi2].zfd, ZT_TONE_RINGTONE);
-				os1 = p0->subs[SUB_REAL].owner->_state;
+		    p1->subs[SUB_THREEWAY].inthreeway && 
+		    p1->subs[SUB_REAL].owner && 
+		    p1->subs[SUB_REAL].inthreeway && 
+		    (p1->subs[SUB_REAL].owner->_state == AST_STATE_RINGING)) {
+			ast_log(LOG_DEBUG, "Playing ringback on %s since %s is in a ringing three-way\n", c0->name, c1->name);
+			tone_zone_play_tone(p0->subs[oi0].zfd, ZT_TONE_RINGTONE);
+			os1 = p1->subs[SUB_REAL].owner->_state;
+		} else {
+			ast_log(LOG_DEBUG, "Stopping tones on %d/%d talking to %d/%d\n", p0->channel, oi0, p1->channel, oi1);
+			tone_zone_play_tone(p0->subs[oi0].zfd, -1);
+		}
+		if ((oi0 == SUB_THREEWAY) && 
+		    p0->subs[SUB_THREEWAY].inthreeway && 
+		    p0->subs[SUB_REAL].owner && 
+		    p0->subs[SUB_REAL].inthreeway && 
+		    (p0->subs[SUB_REAL].owner->_state == AST_STATE_RINGING)) {
+			ast_log(LOG_DEBUG, "Playing ringback on %s since %s is in a ringing three-way\n", c1->name, c0->name);
+			tone_zone_play_tone(p1->subs[oi1].zfd, ZT_TONE_RINGTONE);
+			os0 = p0->subs[SUB_REAL].owner->_state;
 		} else {
-				ast_log(LOG_DEBUG, "Stoping tones on %d/%d talking to %d/%d\n", p1->channel, oi2, p0->channel, oi1);
-				tone_zone_play_tone(p1->subs[oi1].zfd, -1);
+			ast_log(LOG_DEBUG, "Stopping tones on %d/%d talking to %d/%d\n", p1->channel, oi1, p0->channel, oi0);
+			tone_zone_play_tone(p1->subs[oi0].zfd, -1);
 		}
-		if ((oi1 == SUB_REAL) && (oi2 == SUB_REAL)) {
+		if ((oi0 == SUB_REAL) && (oi1 == SUB_REAL)) {
 			if (!p0->echocanbridged || !p1->echocanbridged) {
 				/* Disable echo cancellation if appropriate */
 				zt_disable_ec(p0);
@@ -2927,12 +2954,12 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 		zt_link(slave, master);
 		master->inconference = inconf;
 	} else if (!nothingok)
-		ast_log(LOG_WARNING, "Can't link %d/%s with %d/%s\n", p0->channel, subnames[oi1], p1->channel, subnames[oi2]);
+		ast_log(LOG_WARNING, "Can't link %d/%s with %d/%s\n", p0->channel, subnames[oi0], p1->channel, subnames[oi1]);
 
 	update_conf(p0);
 	update_conf(p1);
-	t1 = p0->subs[SUB_REAL].inthreeway;
-	t2 = p1->subs[SUB_REAL].inthreeway;
+	t0 = p0->subs[SUB_REAL].inthreeway;
+	t1 = p1->subs[SUB_REAL].inthreeway;
 
 	ast_mutex_unlock(&p0->lock);
 	ast_mutex_unlock(&p1->lock);
@@ -2942,17 +2969,22 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 
 	/* Native bridge failed */
 	if ((!master || !slave) && !nothingok) {
-		if (op0 == p0)
-			zt_enable_ec(p0);
-		if (op1 == p1)
-			zt_enable_ec(p1);
-		return -1;
+		zt_enable_ec(p0);
+		zt_enable_ec(p1);
+		return AST_BRIDGE_FAILED;
 	}
 	
-	cs[0] = c0;
-	cs[1] = c1;
-	cs[2] = NULL;
+	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_0))
+		disable_dtmf_detect(op0);
+
+	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_1))
+		disable_dtmf_detect(op1);
+
 	for (;;) {
+		struct ast_channel *c0_priority[2] = {c0, c1};
+		struct ast_channel *c1_priority[2] = {c1, c0};
+		int priority = 0;
+
 		/* Here's our main loop...  Start by locking things, looking for private parts, 
 		   and then balking if anything is wrong */
 		ast_mutex_lock(&c0->lock);
@@ -2964,94 +2996,84 @@ static int zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags,
 		q931c0 = p0->call;
 		q931c1 = p1->call;
 		if (p0->transfer && p1->transfer 
-				&& q931c0 && q931c1 
-				&& !triedtopribridge) {
-
+		    && q931c0 && q931c1 
+		    && !triedtopribridge) {
 			pri_channel_bridge(q931c0, q931c1);
 			triedtopribridge = 1;
 		}
 #endif
+
 		if (op0 == p0)
-			i1 = zt_get_index(c0, p0, 1);
+			i0 = zt_get_index(c0, p0, 1);
 		if (op1 == p1)
-			i2 = zt_get_index(c1, p1, 1);
+			i1 = zt_get_index(c1, p1, 1);
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		if ((op0 != p0) || (op1 != p1) || 
-		    (ofd1 != c0->fds[0]) || 
-			(ofd2 != c1->fds[0]) ||
-		    (p0->subs[SUB_REAL].owner && (os1 > -1) && (os1 != p0->subs[SUB_REAL].owner->_state)) || 
-		    (p1->subs[SUB_REAL].owner && (os2 > -1) && (os2 != p1->subs[SUB_REAL].owner->_state)) || 
-		    (oc1 != p0->owner) || 
-			(oc2 != p1->owner) ||
-			(t1 != p0->subs[SUB_REAL].inthreeway) ||
-			(t2 != p1->subs[SUB_REAL].inthreeway) ||
-			(oi1 != i1) ||
-			(oi2 != i2)) {
-			if (slave && master)
-				zt_unlink(slave, master, 1);
+
+		if ((op0 != p0) ||
+		    (op1 != p1) || 
+		    (ofd0 != c0->fds[0]) || 
+		    (ofd1 != c1->fds[0]) ||
+		    (p0->subs[SUB_REAL].owner && (os0 > -1) && (os0 != p0->subs[SUB_REAL].owner->_state)) || 
+		    (p1->subs[SUB_REAL].owner && (os1 > -1) && (os1 != p1->subs[SUB_REAL].owner->_state)) || 
+		    (oc0 != p0->owner) || 
+		    (oc1 != p1->owner) ||
+		    (t0 != p0->subs[SUB_REAL].inthreeway) ||
+		    (t1 != p1->subs[SUB_REAL].inthreeway) ||
+		    (oi0 != i0) ||
+		    (oi1 != i0)) {
 			ast_log(LOG_DEBUG, "Something changed out on %d/%d to %d/%d, returning -3 to restart\n",
-									op0->channel, oi1, op1->channel, oi2);
-			if (op0 == p0)
-				zt_enable_ec(p0);
-			if (op1 == p1)
-				zt_enable_ec(p1);
-			return -3;
+				op0->channel, oi0, op1->channel, oi1);
+			res = AST_BRIDGE_RETRY;
+			goto return_from_bridge;
 		}
 		to = -1;
-		who = ast_waitfor_n(cs, 2, &to);
+		who = ast_waitfor_n(priority ? c0_priority : c1_priority, 2, &to);
 		if (!who) {
 			ast_log(LOG_DEBUG, "Ooh, empty read...\n");
 			continue;
 		}
-		if (who->tech_pvt == op0) 
-			op0->ignoredtmf = 1;
-		else if (who->tech_pvt == op1)
-			op1->ignoredtmf = 1;
 		f = ast_read(who);
-		if (who->tech_pvt == op0) 
-			op0->ignoredtmf = 0;
-		else if (who->tech_pvt == op1)
-			op1->ignoredtmf = 0;
-		if (!f) {
-			*fo = NULL;
-			*rc = who;
-			if (slave && master)
-				zt_unlink(slave, master, 1);
-			if (op0 == p0)
-				zt_enable_ec(p0);
-			if (op1 == p1)
-				zt_enable_ec(p1);
-			return 0;
-		}
-		if (f->frametype == AST_FRAME_CONTROL) {
+		if (!f || (f->frametype == AST_FRAME_CONTROL)) {
 			*fo = f;
 			*rc = who;
-			if (slave && master)
-				zt_unlink(slave, master, 1);
-			return 0;
+			res = AST_BRIDGE_COMPLETE;
+			goto return_from_bridge;
 		}
 		if (f->frametype == AST_FRAME_DTMF) {
-			if (((who == c0) && (flags & AST_BRIDGE_DTMF_CHANNEL_0)) || 
-			    ((who == c1) && (flags & AST_BRIDGE_DTMF_CHANNEL_1))) {
-				*fo = f;
-				*rc = who;
-				if (slave && master)
-					zt_unlink(slave, master, 1);
-				return 0;
-			} else if ((who == c0) && p0->pulsedial) {
+			if ((who == c0) && p0->pulsedial) {
 				ast_write(c1, f);
-			} else if ((who == c1) && p1->pulsedial) {
+			} else if (p1->pulsedial) {
 				ast_write(c0, f);
+			} else {
+				*fo = f;
+				*rc = who;
+				res = AST_BRIDGE_COMPLETE;
+				goto return_from_bridge;
 			}
 		}
 		ast_frfree(f);
-
+		
 		/* Swap who gets priority */
-		cs[2] = cs[0];
-		cs[0] = cs[1];
-		cs[1] = cs[2];
+		priority = !priority;
 	}
+
+return_from_bridge:
+	if (op0 == p0)
+		zt_enable_ec(p0);
+
+	if (op1 == p1)
+		zt_enable_ec(p1);
+
+	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_0))
+		enable_dtmf_detect(op0);
+
+	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_1))
+		enable_dtmf_detect(op1);
+
+	zt_unlink(slave, master, 1);
+
+	return res;
 }
 
 static int zt_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index de2099288..cd45cb1a3 100755
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -53,6 +53,13 @@ extern "C" {
 
 #define AST_MAX_FDS		8
 
+enum ast_bridge_result {
+	AST_BRIDGE_COMPLETE = 0,
+	AST_BRIDGE_FAILED = -1,
+	AST_BRIDGE_FAILED_NOWARN = -2,
+	AST_BRIDGE_RETRY = -3,
+};
+
 typedef unsigned long long ast_group_t;
 
 struct ast_generator {
@@ -130,8 +137,8 @@ struct ast_channel_tech {
 	struct ast_frame * (* const exception)(struct ast_channel *chan);
 
 	/*! Bridge two channels of the same type together */
-	int (* const bridge)(struct ast_channel *c0, struct ast_channel *c1, int flags,
-			     struct ast_frame **fo, struct ast_channel **rc);
+	enum ast_bridge_result (* const bridge)(struct ast_channel *c0, struct ast_channel *c1, int flags,
+						struct ast_frame **fo, struct ast_channel **rc);
 
 	/*! Indicate a particular condition (e.g. AST_CONTROL_BUSY or AST_CONTROL_RINGING or AST_CONTROL_CONGESTION */
 	int (* const indicate)(struct ast_channel *c, int condition);
diff --git a/rtp.c b/rtp.c
index 31f98a5cd..642a821ad 100755
--- a/rtp.c
+++ b/rtp.c
@@ -1425,7 +1425,7 @@ static struct ast_rtp_protocol *get_proto(struct ast_channel *chan)
 /* ast_rtp_bridge: Bridge calls. If possible and allowed, initiate
 	re-invite so the peers exchange media directly outside 
 	of Asterisk. */
-int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
+enum ast_bridge_result ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
 {
 	struct ast_frame *f;
 	struct ast_channel *who, *cs[3];
@@ -1449,7 +1449,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 
 	/* if need DTMF, cant native bridge */
 	if (flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 
 	/* Lock channels */
 	ast_mutex_lock(&c0->lock);
@@ -1466,13 +1466,13 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 		ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c0->name);
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		return -1;
+		return AST_BRIDGE_FAILED;
 	}
 	if (!pr1) {
 		ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c1->name);
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		return -1;
+		return AST_BRIDGE_FAILED;
 	}
 
 	/* Get channel specific interface structures */
@@ -1496,7 +1496,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 		/* Somebody doesn't want to play... */
 		ast_mutex_unlock(&c0->lock);
 		ast_mutex_unlock(&c1->lock);
-		return -2;
+		return AST_BRIDGE_FAILED_NOWARN;
 	}
 	/* Get codecs from both sides */
 	if (pr0->get_codec)
@@ -1514,7 +1514,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 				ast_log(LOG_DEBUG, "Channel codec0 = %d is not codec1 = %d, cannot native bridge in RTP.\n", codec0, codec1);
 			ast_mutex_unlock(&c0->lock);
 			ast_mutex_unlock(&c1->lock);
-			return -2;
+			return AST_BRIDGE_FAILED_NOWARN;
 		}
 	}
 
@@ -1559,8 +1559,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 					if (pr1->set_rtp_peer(c1, NULL, NULL, 0)) 
 						ast_log(LOG_WARNING, "Channel '%s' failed to break RTP bridge\n", c1->name);
 				}
-				/* Tell it to try again later */
-				return -3;
+				return AST_BRIDGE_RETRY;
 		}
 		to = -1;
 		/* Now check if they have changed address */
@@ -1629,8 +1628,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 				if (pr1->set_rtp_peer(c1, NULL, NULL, 0)) 
 					ast_log(LOG_WARNING, "Channel '%s' failed to break RTP bridge\n", c1->name);
 			}
-			/* That's all we needed */
-			return 0;
+			return AST_BRIDGE_COMPLETE;
 		} else {
 			if ((f->frametype == AST_FRAME_DTMF) || 
 				(f->frametype == AST_FRAME_VOICE) || 
@@ -1650,7 +1648,7 @@ int ast_rtp_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, st
 		cs[1] = cs[2];
 		
 	}
-	return -1;
+	return AST_BRIDGE_FAILED;
 }
 
 static int rtp_do_debug_ip(int fd, int argc, char *argv[])