Index: pbx.c
===================================================================
RCS file: /usr/cvsroot/asterisk/pbx.c,v
retrieving revision 1.271
diff -u -r1.271 pbx.c
--- pbx.c	2 Sep 2005 18:07:26 -0000	1.271
+++ pbx.c	6 Sep 2005 08:37:59 -0000
@@ -2426,6 +2426,7 @@
 		ast_log(LOG_WARNING, "Asked to start thread on NULL channel?\n");
 		return -1;
 	}
+	ast_clear_flag(c, AST_FLAG_PBX_CALL_LIMIT_EXCEEDED);
 	   
 	/* Start a new thread, and get something handling this channel. */
 	pthread_attr_init(&attr);
@@ -2444,6 +2445,7 @@
 	if (option_maxcalls) {
 		if (countcalls >= option_maxcalls) {
 			ast_log(LOG_NOTICE, "Maximum call limit of %d calls exceeded by '%s'!\n", option_maxcalls, c->name);
+			ast_set_flag(c, AST_FLAG_PBX_CALL_LIMIT_EXCEEDED);
 			res = -1;
 		}
 	}
Index: include/asterisk/channel.h
===================================================================
RCS file: /usr/cvsroot/asterisk/include/asterisk/channel.h,v
retrieving revision 1.99
diff -u -r1.99 channel.h
--- include/asterisk/channel.h	1 Sep 2005 00:10:49 -0000	1.99
+++ include/asterisk/channel.h	6 Sep 2005 08:37:59 -0000
@@ -149,7 +149,7 @@
 	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 */
+	/*! 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);
 
 	/*! Fix up a channel:  If a channel is consumed, this is called.  Basically update any ->owner links */
@@ -372,6 +372,7 @@
 						   so when ->priority is set, it will get incremented before
 						   finding the next priority to run
 						*/
+#define AST_FLAG_PBX_CALL_LIMIT_EXCEEDED	(1 << 10)	/* PBX could not start, call limit exceeded */
 
 #define AST_FEATURE_PLAY_WARNING	(1 << 0)
 #define AST_FEATURE_REDIRECT		(1 << 1)
@@ -461,6 +462,8 @@
 /* Bits 16-32 of state are reserved for flags */
 /*! Do not transmit voice data */
 #define AST_STATE_MUTE		(1 << 16)	
+/*! Call blocked by Maxcalls PBX call limit */
+#define AST_STATE_MAXCALL_LIMIT_HIT	(1 << 17)	
 
 /*! Create a channel structure */
 /*! Returns NULL on failure to allocate. New channels are 
Index: channels/chan_sip.c
===================================================================
RCS file: /usr/cvsroot/asterisk/channels/chan_sip.c,v
retrieving revision 1.836
diff -u -r1.836 chan_sip.c
--- channels/chan_sip.c	2 Sep 2005 19:24:32 -0000	1.836
+++ channels/chan_sip.c	6 Sep 2005 08:38:02 -0000
@@ -9712,17 +9712,31 @@
 			transmit_response(p, "100 Trying", req);
 			ast_setstate(c, AST_STATE_RING);
 			if (strcmp(p->exten, ast_pickup_ext())) {
-				if (ast_pbx_start(c)) {
-					ast_log(LOG_WARNING, "Failed to start PBX :(\n");
+				/* Normal call */
+				int res = ast_pbx_start(c);
+				if (!res)	/* PBX thread started */
+					usleep(10);	/* Wait for pbx thread to settle */
+				if (res || ast_test_flag(c, AST_FLAG_PBX_CALL_LIMIT_EXCEEDED)) {
+					if (!res) {
+						/* Call limit exceeded - se option maxcalls in asterisk.conf */
+						ast_log(LOG_WARNING, "Failed to start PBX - too many concurrent calls :-( (See option maxcalls in asterisk.conf)\n");
+						if (ignore)
+							transmit_response(p, "480 Temporarily Unavailable (PBX Call limit)", req);
+						else
+							transmit_response_reliable(p, "480 Temporarily Unavailable (PBX Call limit)", req, 1);
+					} else {
+						ast_log(LOG_WARNING, "Failed to start PBX  :-(\n");
+						if (ignore)
+							transmit_response(p, "503 Service Unavailable", req);
+						else
+							transmit_response_reliable(p, "503 Service Unavailable", req, 1);
+					}
 					/* Unlock locks so ast_hangup can do its magic */
+					ast_set_flag(p, SIP_ALREADYGONE);	/* Don't send BYE :-) */
 					ast_mutex_unlock(&c->lock);
 					ast_mutex_unlock(&p->lock);
 					ast_hangup(c);
 					ast_mutex_lock(&p->lock);
-					if (ignore)
-						transmit_response(p, "503 Unavailable", req);
-					else
-						transmit_response_reliable(p, "503 Unavailable", req, 1);
 					c = NULL;
 				}
 			} else {
Index: channels/chan_iax2.c
===================================================================
RCS file: /usr/cvsroot/asterisk/channels/chan_iax2.c,v
retrieving revision 1.340
diff -u -r1.340 chan_iax2.c
--- channels/chan_iax2.c	2 Sep 2005 19:17:19 -0000	1.340
+++ channels/chan_iax2.c	6 Sep 2005 08:38:04 -0000
@@ -3319,15 +3319,18 @@
 		usecnt++;
 		ast_mutex_unlock(&usecnt_lock);
 		ast_update_use_count();
+		for (v = i->vars ; v; v = v->next)
+			pbx_builtin_setvar_helper(tmp, v->name, v->value);
 		if (state != AST_STATE_DOWN) {
-			if (ast_pbx_start(tmp)) {
-				ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
+			int res = ast_pbx_start(tmp);
+			if (!res)
+				usleep(10);	/* Wait for PBX thread to start */
+			if (res || ast_test_flag(tmp, AST_FLAG_PBX_CALL_LIMIT_EXCEEDED)) {
+				ast_log(LOG_WARNING, "Unable to start PBX on %s %s\n", tmp->name, res ? "" : "(PBX call limit exceeded)");
 				ast_hangup(tmp);
 				tmp = NULL;
 			}
 		}
-		for (v = i->vars ; v ; v = v->next)
-			pbx_builtin_setvar_helper(tmp,v->name,v->value);
 		
 	}
 	return tmp;