diff --git a/CHANGES b/CHANGES
index 7e4abc3136457fbad8a76b9777f7425ee6cf0a62..d4d4236c9577e38bc2cc8433e8ac7c3d8d150e4d 100755
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,4 @@
+ -- Add monitor support (Thanks, Mahmut)
  -- Add experimental "trunk" option to IAX2 for high density VoIP
  -- Add experimental "debug channel" command
  -- Add 'C' flag to dial command to reset call detail record (handy for calling cards)
diff --git a/CREDITS b/CREDITS
index e653bc4b1d8f7443b0cf5dbea72eef0a794d33a5..4d3c0783909c102b558109e4cdc50dd202b8ef10 100755
--- a/CREDITS
+++ b/CREDITS
@@ -35,6 +35,8 @@ Steven Critchfield - Seek and Trunc functions for playback and recording
 Jefferson Noxon - app_lookupcidname, app_db, and various other contributions
 Klaus-Peter Junghanns - in-band DTMF on SIP and MGCP
 Ross Finlayson - Dynamic RTP payload support
+Mahmut Fettahlioglu - Audio recording, music-on-hold changes, alaw file
+		format, and various fixes. Can be contacted at mahmut@oa.com.au
 
 === OTHER SOURCE CODE IN ASTERISK ===
 
diff --git a/channel.c b/channel.c
index 684adac62ca3e6709fcf1e740683391c9b40f5b3..f1ea7f780d0163ec7d4a0f9c42bcf8316077a6a2 100755
--- a/channel.c
+++ b/channel.c
@@ -33,6 +33,7 @@
 #include <asterisk/chanvars.h>
 #include <asterisk/linkedlists.h>
 #include <asterisk/indications.h>
+#include <asterisk/monitor.h>
 
 
 static int shutting_down = 0;
@@ -488,6 +489,10 @@ void ast_channel_free(struct ast_channel *chan)
 		ast_log(LOG_WARNING, "Unable to find channel in list\n");
 	if (chan->pvt->pvt)
 		ast_log(LOG_WARNING, "Channel '%s' may not have been hung up properly\n", chan->name);
+	/* Stop monitoring */
+	if (chan->monitor) {
+		chan->monitor->stop( chan, 0 );
+	}
 	/* Free translatosr */
 	if (chan->pvt->readtrans)
 		ast_translator_free_path(chan->pvt->readtrans);
@@ -1027,6 +1032,10 @@ struct ast_frame *ast_read(struct ast_channel *chan)
 		/* Answer the CDR */
 		ast_setstate(chan, AST_STATE_UP);
 		ast_cdr_answer(chan->cdr);
+	} else if( ( f->frametype == AST_FRAME_VOICE ) && chan->monitor && chan->monitor->read_stream ) {
+		if( ast_writestream( chan->monitor->read_stream, f ) < 0 ) {
+			ast_log(LOG_WARNING, "Failed to write data to channel monitor read stream\n");
+		}
 	}
 	pthread_mutex_unlock(&chan->lock);
 
@@ -1225,7 +1234,16 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr)
 			} else
 				f = fr;
 			if (f)	
+			{
 				res = chan->pvt->write(chan, f);
+				if( chan->monitor &&
+						chan->monitor->write_stream &&
+						f && ( f->frametype == AST_FRAME_VOICE ) ) {
+					if( ast_writestream( chan->monitor->write_stream, f ) < 0 ) {
+						ast_log(LOG_WARNING, "Failed to write data to channel monitor write stream\n");
+					}
+				}
+			}
 			else
 				res = 0;
 		}
@@ -1856,7 +1874,7 @@ int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags
 			break;
 		}
 		if (c0->pvt->bridge && 
-			(c0->pvt->bridge == c1->pvt->bridge) && !nativefailed) {
+			(c0->pvt->bridge == c1->pvt->bridge) && !nativefailed && !c0->monitor && !c1->monitor) {
 				/* Looks like they share a bridge code */
 			if (option_verbose > 2) 
 				ast_verbose(VERBOSE_PREFIX_3 "Attempting native bridge of %s and %s\n", c0->name, c1->name);
@@ -2116,3 +2134,5 @@ int ast_tonepair(struct ast_channel *chan, int freq1, int freq2, int duration, i
 	}
 	return 0;
 }
+
+
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index b14d3c92836cc7cc87347d7cb385b6fcc26f0373..6979515da5a9f9a6bf8a264256585875df13bf2c 100755
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -30,6 +30,7 @@ extern "C" {
 #define AST_MAX_EXTENSION 80
 
 #include <asterisk/cdr.h>
+#include <asterisk/monitor.h>
 
 
 #define AST_CHANNEL_NAME 80
@@ -175,6 +176,9 @@ struct ast_channel {
 	/*! Tone zone */
 	struct tone_zone *zone;
 
+	/* Channel monitoring */
+	struct ast_channel_monitor *monitor;
+
 	/* Frames in/out counters */
 	unsigned int fin;
 	unsigned int fout;
diff --git a/res/Makefile b/res/Makefile
index 686ca9718ddfe7478d9507aef7129fd37c2429bd..deab737232353d279248d6d3181bbb815a773ebe 100755
--- a/res/Makefile
+++ b/res/Makefile
@@ -11,7 +11,7 @@
 # the GNU General Public License
 #
 
-MODS=res_adsi.so res_parking.so res_crypto.so res_musiconhold.so res_indications.so
+MODS=res_adsi.so res_parking.so res_crypto.so res_musiconhold.so res_indications.so res_monitor.so
 
 CRYPTO_LIBS=-lssl -lcrypto
 
diff --git a/res/res_monitor.c b/res/res_monitor.c
new file mode 100755
index 0000000000000000000000000000000000000000..826f0ee3feb30186a5874c28518b757de33f17e0
--- /dev/null
+++ b/res/res_monitor.c
@@ -0,0 +1,443 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include <asterisk/lock.h>
+#include <asterisk/channel.h>
+#include <asterisk/logger.h>
+#include <asterisk/file.h>
+#include <asterisk/pbx.h>
+#include <asterisk/module.h>
+#include <asterisk/manager.h>
+#include <asterisk/cli.h>
+#include <asterisk/monitor.h>
+
+#define AST_MONITOR_DIR	INSTALL_PREFIX "/var/spool/asterisk/monitor"
+
+static pthread_mutex_t monitorlock = AST_MUTEX_INITIALIZER;
+
+static unsigned long seq = 0;
+
+static char *monitor_synopsis = "Monitor a channel";
+
+static char *monitor_descrip = "Monitor\n"
+	"Used to start monitoring a channel. The channel's input and output\n"
+	"voice packets are logged to files until the channel hangs up or\n"
+	"monitoring is stopped by the StopMonitor application.\n"
+	"The option string may contain the following arguments: [file_format|[fname_base]]\n"
+	"	file_format -- optional, if not set, defaults to \"wav\"\n"
+	"	fname_base -- if set, changes the filename used to the one specified.\n";
+
+static char *stopmonitor_synopsis = "Stop monitoring a channel";
+
+static char *stopmonitor_descrip = "StopMonitor\n"
+	"Stops monitoring a channel. Has no effect if the channel is not monitored\n";
+
+static char *changemonitor_synopsis = "Change monitoring filename of a channel";
+
+static char *changemonitor_descrip = "ChangeMonitor\n"
+	"Changes monitoring filename of a channel. Has no effect if the channel is not monitored\n"
+	"The option string may contain the following:\n"
+	"	filename_base -- if set, changes the filename used to the one specified.\n";
+
+/* Start monitoring a channel */
+int ast_monitor_start(	struct ast_channel *chan, const char *format_spec,
+						const char *fname_base, int need_lock )
+{
+	int res = 0;
+
+	if( need_lock ) {
+		if (ast_pthread_mutex_lock(&chan->lock)) {
+			ast_log(LOG_WARNING, "Unable to lock channel\n");
+			return -1;
+		}
+	}
+
+	if( !(chan->monitor) ) {
+		struct ast_channel_monitor *monitor;
+		char *channel_name, *p;
+
+		/* Create monitoring directory if needed */
+		if( mkdir( AST_MONITOR_DIR, 0770 ) < 0 ) {
+			if( errno != EEXIST ) {
+				ast_log(LOG_WARNING, "Unable to create audio monitor directory: %s\n",
+						strerror( errno ) );
+			}
+		}
+
+		monitor = malloc( sizeof( struct ast_channel_monitor ) );
+		memset( monitor, 0, sizeof( struct ast_channel_monitor ) );
+
+		/* Determine file names */
+		if( fname_base && strlen( fname_base ) ) {
+			snprintf(	monitor->read_filename, FILENAME_MAX, "%s/%s-in",
+						AST_MONITOR_DIR, fname_base );
+			snprintf(	monitor->write_filename, FILENAME_MAX, "%s/%s-out",
+						AST_MONITOR_DIR, fname_base );
+			*monitor->filename_base = 0;
+		} else {
+			ast_pthread_mutex_lock( &monitorlock );
+			snprintf(	monitor->read_filename, FILENAME_MAX, "%s/audio-in-%ld",
+						AST_MONITOR_DIR, seq );
+			snprintf(	monitor->write_filename, FILENAME_MAX, "%s/audio-out-%ld",
+						AST_MONITOR_DIR, seq );
+			seq++;
+			ast_pthread_mutex_unlock( &monitorlock );
+
+			channel_name = strdup( chan->name );
+			while( ( p = strchr( channel_name, '/' ) ) ) {
+				*p = '-';
+			}
+			snprintf(	monitor->filename_base, FILENAME_MAX, "%s/%s",
+						AST_MONITOR_DIR, channel_name );
+			free( channel_name );
+		}
+
+		monitor->stop = ast_monitor_stop;
+
+		// Determine file format
+		if( format_spec && strlen( format_spec ) ) {
+			monitor->format = strdup( format_spec );
+		} else {
+			monitor->format = strdup( "wav" );
+		}
+		
+		// open files
+		if( ast_fileexists( monitor->read_filename, NULL, NULL ) > 0 ) {
+			ast_filedelete( monitor->read_filename, NULL );
+		}
+		if( !(monitor->read_stream = ast_writefile(	monitor->read_filename,
+						monitor->format, NULL,
+						O_CREAT|O_TRUNC|O_WRONLY, 0, 0644 ) ) ) {
+			ast_log(	LOG_WARNING, "Could not create file %s\n",
+						monitor->read_filename );
+			free( monitor );
+			ast_pthread_mutex_unlock(&chan->lock);
+			return -1;
+		}
+		if( ast_fileexists( monitor->write_filename, NULL, NULL ) > 0 ) {
+			ast_filedelete( monitor->write_filename, NULL );
+		}
+		if( !(monitor->write_stream = ast_writefile( monitor->write_filename,
+						monitor->format, NULL,
+						O_CREAT|O_TRUNC|O_WRONLY, 0, 0644 ) ) ) {
+			ast_log(	LOG_WARNING, "Could not create file %s\n",
+						monitor->write_filename );
+			ast_closestream( monitor->read_stream );
+			free( monitor );
+			ast_pthread_mutex_unlock(&chan->lock);
+			return -1;
+		}
+		chan->monitor = monitor;
+	} else {
+		ast_log(	LOG_DEBUG,"Cannot start monitoring %s, already monitored\n",
+					chan->name );
+		res = -1;
+	}
+
+	if( need_lock ) {
+		ast_pthread_mutex_unlock(&chan->lock);
+	}
+	return res;
+}
+
+/* Stop monitoring a channel */
+int ast_monitor_stop( struct ast_channel *chan, int need_lock )
+{
+	if(need_lock) {
+		if(ast_pthread_mutex_lock(&chan->lock)) {
+			ast_log(LOG_WARNING, "Unable to lock channel\n");
+			return -1;
+		}
+	}
+
+	if(chan->monitor) {
+		char filename[ FILENAME_MAX ];
+
+		if(chan->monitor->read_stream) {
+			ast_closestream( chan->monitor->read_stream );
+		}
+		if(chan->monitor->write_stream) {
+			ast_closestream( chan->monitor->write_stream );
+		}
+
+		if(chan->monitor->filename_base&&strlen(chan->monitor->filename_base)) {
+			if( ast_fileexists(chan->monitor->read_filename,NULL,NULL) > 0 ) {
+				snprintf(	filename, FILENAME_MAX, "%s-in",
+							chan->monitor->filename_base );
+				if(ast_fileexists( filename, NULL, NULL ) > 0) {
+					ast_filedelete( filename, NULL );
+				}
+				ast_filerename(	chan->monitor->read_filename, filename,
+								chan->monitor->format );
+			} else {
+				ast_log(	LOG_WARNING, "File %s not found\n",
+							chan->monitor->read_filename );
+			}
+
+			if(ast_fileexists(chan->monitor->write_filename,NULL,NULL) > 0) {
+				snprintf(	filename, FILENAME_MAX, "%s-out",
+							chan->monitor->filename_base );
+				if( ast_fileexists( filename, NULL, NULL ) > 0 ) {
+					ast_filedelete( filename, NULL );
+				}
+				ast_filerename(	chan->monitor->write_filename, filename,
+								chan->monitor->format );
+			} else {
+				ast_log(	LOG_WARNING, "File %s not found\n",
+							chan->monitor->write_filename );
+			}
+		}
+
+		free( chan->monitor->format );
+		free( chan->monitor );
+		chan->monitor = NULL;
+	}
+
+	if( need_lock ) {
+		ast_pthread_mutex_unlock(&chan->lock);
+	}
+	return 0;
+}
+
+/* Change monitoring filename of a channel */
+int ast_monitor_change_fname(	struct ast_channel *chan,
+								const char *fname_base, int need_lock )
+{
+	if( (!fname_base) || (!strlen(fname_base)) ) {
+		ast_log(	LOG_WARNING,
+					"Cannot change monitor filename of channel %s to null",
+					chan->name );
+		return -1;
+	}
+	
+	if( need_lock ) {
+		if (ast_pthread_mutex_lock(&chan->lock)) {
+			ast_log(LOG_WARNING, "Unable to lock channel\n");
+			return -1;
+		}
+	}
+
+	if( chan->monitor ) {
+		snprintf(	chan->monitor->filename_base, FILENAME_MAX, "%s/%s",
+					AST_MONITOR_DIR, fname_base );
+	} else {
+		ast_log(	LOG_WARNING,
+					"Cannot change monitor filename of channel %s to %s, monitoring not started",
+					chan->name, fname_base );
+				
+	}
+
+	if( need_lock ) {
+		ast_pthread_mutex_unlock(&chan->lock);
+	}
+	return 0;
+}
+
+static int start_monitor_exec(struct ast_channel *chan, void *data)
+{
+	char *arg = NULL;
+	char *format = NULL;
+	char *fname_base = NULL;
+	int res;
+	
+	/* Parse arguments. */
+	if( data && strlen((char*)data) ) {
+		arg = strdup( (char*)data );
+		format = arg;
+		fname_base = strchr( arg, '|' );
+		if( fname_base ) {
+			*fname_base = 0;
+			fname_base++;
+		}
+	}
+
+	res = ast_monitor_start( chan, format, fname_base, 1 );
+	if( res < 0 ) {
+		res = ast_monitor_change_fname( chan, fname_base, 1 );
+	}
+
+	if( arg ) {
+		free( arg );
+	}
+
+	return res;
+}
+
+static int stop_monitor_exec(struct ast_channel *chan, void *data)
+{
+	return ast_monitor_stop( chan, 1 );
+}
+
+static int change_monitor_exec(struct ast_channel *chan, void *data)
+{
+	return ast_monitor_change_fname( chan, (const char*)data, 1 );
+}
+
+static char *get_header(struct message *m, char *var)
+{
+	char cmp[80];
+	int x;
+	snprintf(cmp, sizeof(cmp), "%s: ", var);
+	for (x=0;x<m->hdrcount;x++)
+		if (!strncasecmp(cmp, m->headers[x], strlen(cmp)))
+			return m->headers[x] + strlen(cmp);
+	return NULL;
+}
+
+static void send_error(struct mansession *s, char *error)
+{
+	ast_pthread_mutex_lock(&s->lock);
+	ast_cli(s->fd, "Response: Error\r\n");
+	ast_cli(s->fd, "Message: %s\r\n\r\n", error);
+	ast_pthread_mutex_unlock(&s->lock);
+}
+
+static void send_response(struct mansession *s, char *resp, char *msg)
+{
+	ast_pthread_mutex_lock(&s->lock);
+	ast_cli(s->fd, "Response: %s\r\n", resp);
+	if (msg)
+		ast_cli(s->fd, "Message: %s\r\n\r\n", msg);
+	else
+		ast_cli(s->fd, "\r\n");
+	ast_pthread_mutex_unlock(&s->lock);
+}
+
+static void send_ack(struct mansession *s, char *msg)
+{
+	send_response(s, "Success", msg);
+}
+
+static int start_monitor_action(struct mansession *s, struct message *m)
+{
+	struct ast_channel *c = NULL;
+	char *name = get_header(m, "Channel");
+	char *fname = get_header(m, "File");
+	char *format = get_header(m, "Format");
+	if((!name)||(!strlen(name))) {
+		send_error(s, "No channel specified");
+		return 0;
+	}
+	c = ast_channel_walk(NULL);
+	while(c) {
+		if (!strcasecmp(c->name, name)) {
+			break;
+		}
+		c = ast_channel_walk(c);
+	}
+	if (!c) {
+		send_error(s, "No such channel");
+		return 0;
+	}
+	if( ast_monitor_start( c, format, fname, 1 ) ) {
+		if( ast_monitor_change_fname( c, fname, 1 ) ) {
+			send_error(s, "Could not start monitoring channel");
+			return 0;
+		}
+	}
+	send_ack(s, "Started monitoring channel");
+	return 0;
+}
+
+static int stop_monitor_action(struct mansession *s, struct message *m)
+{
+	struct ast_channel *c = NULL;
+	char *name = get_header(m, "Channel");
+	if((!name)||(!strlen(name))) {
+		send_error(s, "No channel specified");
+		return 0;
+	}
+	c = ast_channel_walk(NULL);
+	while(c) {
+		if (!strcasecmp(c->name, name)) {
+			break;
+		}
+		c = ast_channel_walk(c);
+	}
+	if (!c) {
+		send_error(s, "No such channel");
+		return 0;
+	}
+	if( ast_monitor_stop( c, 1 ) ) {
+		send_error(s, "Could not stop monitoring channel");
+		return 0;
+	}
+	send_ack(s, "Stopped monitoring channel");
+	return 0;
+}
+
+static int change_monitor_action(struct mansession *s, struct message *m)
+{
+	struct ast_channel *c = NULL;
+	char *name = get_header(m, "Channel");
+	char *fname = get_header(m, "File");
+	if((!name) || (!strlen(name))) {
+		send_error(s, "No channel specified");
+		return 0;
+	}
+	if ((!fname)||(!strlen(fname))) {
+		send_error(s, "No filename specified");
+		return 0;
+	}
+	c = ast_channel_walk(NULL);
+	while(c) {
+		if (!strcasecmp(c->name, name)) {
+			break;
+		}
+		c = ast_channel_walk(c);
+	}
+	if (!c) {
+		send_error(s, "No such channel");
+		return 0;
+	}
+	if( ast_monitor_change_fname( c, fname, 1 ) ) {
+		send_error(s, "Could not change monitored filename of channel");
+		return 0;
+	}
+	send_ack(s, "Stopped monitoring channel");
+	return 0;
+}
+
+int load_module(void)
+{
+	ast_register_application( "Monitor", start_monitor_exec, monitor_synopsis, monitor_descrip );
+	ast_register_application( "StopMonitor", stop_monitor_exec, stopmonitor_synopsis, stopmonitor_descrip );
+	ast_register_application( "ChangeMonitor", change_monitor_exec, changemonitor_synopsis, changemonitor_descrip );
+	ast_manager_register( "Monitor", EVENT_FLAG_CALL, start_monitor_action, monitor_synopsis );
+	ast_manager_register( "StopMonitor", EVENT_FLAG_CALL, stop_monitor_action, stopmonitor_synopsis );
+	ast_manager_register( "ChangeMonitor", EVENT_FLAG_CALL, change_monitor_action, changemonitor_synopsis );
+
+	return 0;
+}
+
+int unload_module(void)
+{
+	ast_unregister_application( "Monitor" );
+	ast_unregister_application( "StopMonitor" );
+	return 0;
+}
+
+char *description(void)
+{
+	return "Call Monitoring Resource";
+}
+
+int usecount(void)
+{
+	/* Never allow monitor to be unloaded because it will
+	   unresolve needed symbols in the channel */
+#if 0
+	int res;
+	STANDARD_USECOUNT(res);
+	return res;
+#else
+	return 1;
+#endif
+}
+
+char *key()
+{
+	return ASTERISK_GPL_KEY;
+}