diff --git a/page.html b/page.html
new file mode 100755
index 0000000..4549d3a
--- /dev/null
+++ b/page.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+		<title>Websocket Test</title>
+	</head>
+	<body>
+		<button type="button" onclick="connect()">Connect</button>
+		<script>
+			function connect() {
+				var ws = new WebSocket("ws://" + location.host);
+				ws.onopen = function() {
+					console.log("connect ok");
+					ws.send("Hello WebSocket");
+				};
+				
+				ws.onmessage = function (evt) {
+					console.log("recv:"+evt.data);
+				};
+				
+				ws.onclose = function() {
+					console.log("close");
+				};
+			}
+		</script>
+	</body>
+</html>
\ No newline at end of file
diff --git a/xterminal_broker.c b/xterminal_broker.c
index a6ca5d4..6133a28 100755
--- a/xterminal_broker.c
+++ b/xterminal_broker.c
@@ -5,6 +5,14 @@
 int asprintf(char **strp, const char *fmt, ...);
 void *memmem(const void *haystack, size_t haystacklen, const void *needle, size_t needlelen);
 
+static LIST_HEAD(device_list);
+
+struct device {
+	char mac[13];
+	int alive;
+	struct list_head node;
+};
+
 static char *macaddr;
 static char *myid;
 
@@ -14,6 +22,38 @@ static const char *index_page = "<!DOCTYPE html><html><head>"
 	"<script>function connect(){var ws = new WebSocket(\"ws://\" + location.host);ws.onopen = function() {"
 	"console.log(\"connect ok\");ws.send(\"Hello WebSocket\");};ws.onmessage = function (evt) {"
 	"console.log(\"recv:\"+evt.data);};ws.onclose = function(){console.log(\"close\");};}</script></body></html>";
+
+
+static struct device *find_device_by_mac(struct mg_str *mac)
+{
+	struct device *dev = NULL;
+	
+	list_for_each_entry(dev, &device_list, node) {
+		if (!mg_vcmp(mac, dev->mac))
+			return dev;
+	}
+	
+	return NULL;
+}
+
+static void update_device(struct mg_str *mac)
+{
+	struct device *dev = find_device_by_mac(mac);
+	if (!dev) {
+		dev = calloc(1, sizeof(struct device));
+		if (!dev) {
+			perror("calloc");
+			return;
+		}
+		
+		list_add(&dev->node, &device_list);
+		strncpy(dev->mac, mac->p, mac->len);
+	}
+	
+	dev->alive = 10;
+
+	printf("update_device:%s\n", dev->mac);
+}
 	
 static void ev_handler(struct mg_connection *nc, int ev, void *ev_data)
 {
@@ -27,7 +67,7 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data)
 		
 	} else if (ev == MG_EV_MQTT_CONNACK) {
 		struct mg_mqtt_message *msg = (struct mg_mqtt_message *)ev_data;
-		struct mg_mqtt_topic_expression topic_expr[2];
+		struct mg_mqtt_topic_expression topic_expr[1];
 		
 		if (msg->connack_ret_code != MG_EV_MQTT_CONNACK_ACCEPTED) {
 			printf("Got mqtt connection error: %d\n", msg->connack_ret_code);
@@ -36,15 +76,11 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data)
 		}
 
 		topic_expr[0].qos = MG_MQTT_QOS(0);
-		asprintf((char **)&topic_expr[0].topic, "xterminal/%s/response/data/%s", macaddr, myid);
+		asprintf((char **)&topic_expr[0].topic, "xterminal/heartbeat");
 		
-		topic_expr[1].qos = MG_MQTT_QOS(0);
-		asprintf((char **)&topic_expr[1].topic, "xterminal/%s/response/exit/%s", macaddr, myid);
-		
-		mg_mqtt_subscribe(nc, topic_expr, 2, 0);
+		mg_mqtt_subscribe(nc, topic_expr, 1, 0);
 
 		free((char *)topic_expr[0].topic);
-		free((char *)topic_expr[1].topic);
 		
 	} else if (ev == MG_EV_MQTT_SUBACK) {
 		char topic[128] = "";
@@ -53,19 +89,27 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data)
 		
 	} else if (ev == MG_EV_MQTT_PUBLISH) {
 		struct mg_mqtt_message *msg = (struct mg_mqtt_message *)ev_data;
-		if (memmem(msg->topic.p, msg->topic.len, "data", strlen("data"))) {
-			int ret = write(STDOUT_FILENO, msg->payload.p, msg->payload.len);
-			if (ret < 0)
-				perror("write");
-		} else if (memmem(msg->topic.p, msg->topic.len, "exit", strlen("exit"))) {
-			ev_break(EV_DEFAULT, EVBREAK_ALL);
+		
+		if (!mg_vcmp(&msg->topic, "xterminal/heartbeat")) {
+			update_device(&msg->payload);
 		}
 			
 	} else if (ev == MG_EV_HTTP_REQUEST) {
-		mg_printf(nc, "HTTP/1.1 200 OK\r\n"
-							  "Content-Length: %d\r\n\r\n"
-							  "%s", (int)strlen(index_page), index_page);
-		
+		struct http_message *hm = (struct http_message *)ev_data;
+		if (!mg_vcmp(&hm->uri, "/list")) {
+			struct device *dev;
+			
+			mg_send_head(nc, 200, -1, NULL);
+			
+			list_for_each_entry(dev, &device_list, node) {
+				mg_printf_http_chunk(nc, "%s|", dev->mac);
+			}
+			
+			mg_send_http_chunk(nc, "", 0);
+		} else {
+			mg_send_head(nc, 200, strlen(index_page), NULL);
+			mg_printf(nc, "%s", index_page);
+		}
 	} else if (ev == MG_EV_WEBSOCKET_HANDSHAKE_DONE) {
 		char buf[] = "Hello Websocket Client";
 		printf("New websocket connection:%p\n", nc);
@@ -80,23 +124,24 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data)
 	}
 }
 
+static void device_alive_cb(struct ev_loop *loop, ev_timer *w, int revents)
+{
+	struct device *dev, *tmp;
+	
+	list_for_each_entry_safe(dev, tmp, &device_list, node) {
+		if (dev->alive-- == 0) {
+			printf("del device:%s\n", dev->mac);
+			list_del(&dev->node);
+			free(dev);
+		}
+	}
+}
+
 static void signal_cb(struct ev_loop *loop, ev_signal *w, int revents)
 {
 	printf("Got signal: %d\n", w->signum);
 	ev_break(loop, EVBREAK_ALL);
 }
-		
-static void usage(const char *name)
-{
-	fprintf(stderr,
-		"Usage: %s [OPTION]\n"
-		"	-m macaddr\n"
-		"	-i id\n"
-		"\n", name
-	);
-	
-	exit(0);
-}
 
 int main(int argc, char *argv[])
 {
@@ -106,30 +151,14 @@ int main(int argc, char *argv[])
 	struct mg_connection *nc;
 	const char *s_address = "localhost:1883";
 	const char *s_http_port = "8000";
-	int ch;
-
-	while ((ch = getopt(argc, argv, "m:i:")) != -1) {
-		switch (ch) {
-		case 'm':
-			macaddr = optarg;
-			break;
-
-		case 'i':
-			myid = optarg;
-			break;
-			
-		default:
-			usage(argv[0]);
-		}
-	}
-	
-	if ((optind < argc) || !macaddr || !myid) {
-		usage(argv[0]);
-	}
+	ev_timer device_timer;
 	
 	ev_signal_init(&sig_watcher, signal_cb, SIGINT);
 	ev_signal_start(loop, &sig_watcher);
 	
+	ev_timer_init(&device_timer, device_alive_cb, 0.1, 2.0);
+	ev_timer_start(loop, &device_timer);
+	
 	mg_mgr_init(&mgr, NULL);
 
 	nc = mg_connect(&mgr, s_address, ev_handler);
diff --git a/xterminal_client.c b/xterminal_client.c
index 45f816d..4b25fc7 100755
--- a/xterminal_client.c
+++ b/xterminal_client.c
@@ -18,7 +18,6 @@ void *memmem(const void *haystack, size_t haystacklen, const void *needle, size_
 LIST_HEAD(clients);
 
 static char *devid;
-static const char *s_address = "localhost:1883";
 
 static void pty_read_cb(struct ev_loop *loop, ev_io *w, int revents)
 {
@@ -141,6 +140,14 @@ static void signal_cb(struct ev_loop *loop, ev_signal *w, int revents)
 	}
 }
 
+static void heartbeat_cb(struct ev_loop *loop, ev_timer *w, int revents)
+{
+	struct mg_connection *nc = (struct mg_connection *)w->data;
+	
+	mg_mqtt_publish(nc, "xterminal/heartbeat", 0, MG_MQTT_QOS(0), devid, strlen(devid));
+	printf("send heartbeat:%s\n", devid);
+}
+
 static int get_iface_mac(const char *ifname, char mac[6])
 {
     int r, s;
@@ -174,9 +181,11 @@ int main(int argc, char *argv[])
 	struct ev_loop *loop = EV_DEFAULT;
 	ev_signal sigint_watcher;
 	ev_signal sigchld_watcher;
+	ev_timer heartbeat_timer;
 	struct mg_mgr mgr;
 	struct mg_connection *nc;
 	char mac[6] = "";
+	const char *s_address = "localhost:1883";
 	
 	mg_mgr_init(&mgr, NULL);
 
@@ -193,6 +202,10 @@ int main(int argc, char *argv[])
 	ev_signal_init(&sigchld_watcher, signal_cb, SIGCHLD);
 	sigchld_watcher.data = nc;
 	ev_signal_start(loop, &sigchld_watcher);
+	
+	ev_timer_init(&heartbeat_timer, heartbeat_cb, 0.1, 2.0);
+	heartbeat_timer.data = nc;
+	ev_timer_start(loop, &heartbeat_timer);
 
 	get_iface_mac("enp3s0", mac);