diff --git a/src/download.c b/src/download.c
index 2dda9b2..c0f73bf 100644
--- a/src/download.c
+++ b/src/download.c
@@ -111,7 +111,10 @@ char *download_file_task_function(char *task)
 
 int download_file_in_subprocess(const char *file_path, const char *url, const char *username, const char *password)
 {
-	subprocess_start(download_file_task_function);
+	if (CWMP_OK != subprocess_start(download_file_task_function)) {
+		CWMP_LOG(ERROR, "Failed to spawn subprocess to start download");
+		return 500;
+	}
 
 	if (url == NULL) {
 		CWMP_LOG(ERROR, "download %s: url is null");
diff --git a/src/http.c b/src/http.c
index 4618fce..99a9590 100644
--- a/src/http.c
+++ b/src/http.c
@@ -263,14 +263,36 @@ error:
 	return -1;
 }
 
+static void inform_status_check_cb(struct ubus_request *req, int type __attribute__((unused)), struct blob_attr *msg)
+{
+	if (msg == NULL) {
+		CWMP_LOG(ERROR, "inform ubus call resp msg is null");
+		return;
+	}
+
+	int *status = (int *)req->priv;
+	const struct blobmsg_policy p[2] = { { "status", BLOBMSG_TYPE_INT32 }, { "info", BLOBMSG_TYPE_STRING } };
+	struct blob_attr *tb[2] = { NULL, NULL };
+	blobmsg_parse(p, 2, tb, blobmsg_data(msg), blobmsg_len(msg));
+
+	*status = tb[0] ? blobmsg_get_u32(tb[0]) : -1;
+}
+
 static void http_success_cr(void)
 {
 	CWMP_LOG(INFO, "Connection Request triggering ...");
+	int status = -1, retry = 0, rc = -1;
 	struct blob_buf b = { 0 };
 	memset(&b, 0, sizeof(struct blob_buf));
 	blob_buf_init(&b, 0);
-	icwmp_ubus_invoke("tr069", "inform", b.head, NULL, NULL);
+	while ((rc < 0 || status != 1) && retry < 5) {
+		rc = icwmp_ubus_invoke("tr069", "inform", b.head, inform_status_check_cb, &status);
+		retry = retry + 1;
+	}
+
 	blob_buf_free(&b);
+	if (rc < 0 || status != 1)
+		CWMP_LOG(ERROR, "Failed to send Inform message after 5 retry");
 }
 
 static void http_cr_new_client(int client, bool service_available)
@@ -495,8 +517,7 @@ http_end:
 			fclose(fp);
 		}
 		close(client);
-	}
-	else {
+	} else {
 		CWMP_LOG(INFO, "Receive Connection Request: Return 401 Unauthorized");
 		if (fp) {
 			fputs("HTTP/1.1 401 Unauthorized\r\n", fp);
diff --git a/src/session.c b/src/session.c
index 4e005d9..70cc3fd 100644
--- a/src/session.c
+++ b/src/session.c
@@ -316,21 +316,34 @@ void rpc_exit()
 	FREE(cwmp_main->session->rpc_cpe);
 }
 
+static void schedule_session_retry(void)
+{
+	cwmp_main->retry_count_session++;
+	int t = cwmp_get_retry_interval(0);
+	CWMP_LOG(INFO, "Retry session, retry count = %d, retry in %ds", cwmp_main->retry_count_session, t);
+	cwmp_uci_reinit();
+	cwmp_config_load();
+	trigger_periodic_notify_check();
+	cwmp_uci_exit();
+
+	if (!cwmp_main->session->session_status.is_heartbeat) {
+		set_cwmp_session_status(SESSION_FAILURE, t);
+		uloop_timeout_set(&retry_session_timer, 1000 * t);
+	} else {
+		uloop_timeout_cancel(&heartbeat_session_timer);
+		uloop_timeout_set(&heartbeat_session_timer, 1000 * t);
+	}
+}
+
 void start_cwmp_session()
 {
-	int t, error;
+	int error;
 	char *exec_download = NULL;
 
 	uloop_timeout_cancel(&check_notify_timer);
 	if (cwmp_session_init() != CWMP_OK) {
 		CWMP_LOG(ERROR, "Not able to init a CWMP session");
-		t = cwmp_get_retry_interval(0);
-		CWMP_LOG(INFO, "Retry session, retry count = %d, retry in %ds", cwmp_main->retry_count_session, t);
-		cwmp_uci_reinit();
-		set_cwmp_session_status(SESSION_FAILURE, t);
-		cwmp_config_load();
-		trigger_periodic_notify_check();
-		cwmp_uci_exit();
+		schedule_session_retry();
 		return;
 	}
 
@@ -343,6 +356,8 @@ void start_cwmp_session()
 	if (is_ipv6_status_changed()) {
 		if (icwmp_check_http_connection() != CWMP_OK || cwmp_stop) {
 			CWMP_LOG(INFO, "Failed to check http connection");
+			if (!cwmp_stop)
+				schedule_session_retry();
 			return;
 		}
 	}
@@ -397,9 +412,11 @@ void start_cwmp_session()
 	}
 
 	if (cwmp_main->session->error == CWMP_RETRY_SESSION && (!list_empty(&(cwmp_main->session->events)) || (list_empty(&(cwmp_main->session->events)) && cwmp_main->cwmp_cr_event == 0))) { //CWMP Retry session
+		cwmp_uci_reinit();
 		cwmp_config_load();
+		cwmp_uci_exit();
 		cwmp_main->retry_count_session++;
-		t = cwmp_get_retry_interval(0);
+		int t = cwmp_get_retry_interval(0);
 		CWMP_LOG(INFO, "Retry session, retry count = %d, retry in %ds", cwmp_main->retry_count_session, t);
 		if (!cwmp_main->session->session_status.is_heartbeat) {
 			set_cwmp_session_status(SESSION_FAILURE, t);
diff --git a/src/subprocess.c b/src/subprocess.c
index 2db07c1..7c7363e 100644
--- a/src/subprocess.c
+++ b/src/subprocess.c
@@ -94,7 +94,7 @@ int subprocess_start(task_function task_fun)
     		struct blob_buf bbuf;
     		memset(&bbuf, 0, sizeof(struct blob_buf));
     		blob_buf_init(&bbuf, 0);
-    		blobmsg_add_string(&bbuf, "ret", to_child);
+		blobmsg_add_string(&bbuf, "ret", to_child ? to_child : "500");
     		char *to_child_json = blobmsg_format_json(bbuf.head, true);
     		write(pipefd2[1], to_child_json, strlen(to_child_json)+1);
     		FREE(to_child);
diff --git a/src/ubus_utils.c b/src/ubus_utils.c
index 605c6da..7e51b59 100644
--- a/src/ubus_utils.c
+++ b/src/ubus_utils.c
@@ -269,7 +269,7 @@ static int icwmp_inform_event(struct blob_buf *bb, char *event)
 	int event_code = cwmp_get_int_event_code(event);
 	if (event_code != -1) {
 		if (cwmp_main->session->session_status.last_status == SESSION_RUNNING) {
-			blobmsg_add_u32(bb, "status", -1);
+			blobmsg_add_u32(bb, "status", 1);
 			blobmsg_add_string(bb, "info", "Session already running, event will be sent at the end of the session");
 		} else {
 			blobmsg_add_u32(bb, "status", 1);