diff --git a/lib/pscom/pscom_con.c b/lib/pscom/pscom_con.c
index 5d12ffeb..17c96900 100644
--- a/lib/pscom/pscom_con.c
+++ b/lib/pscom/pscom_con.c
@@ -387,6 +387,8 @@ pscom_con_t *pscom_con_create(pscom_sock_t *sock)
 	INIT_LIST_HEAD(&con->poll_reader.next);
 	INIT_LIST_HEAD(&con->poll_next_send);
 
+	INIT_LIST_HEAD(&con->shutdown_requested);
+
 	con->con_guard.fd = -1;
 	con->precon = NULL;
 	con->in.req	= 0;
diff --git a/lib/pscom/pscom_migrate.c b/lib/pscom/pscom_migrate.c
index e42e2423..e4a112dd 100644
--- a/lib/pscom/pscom_migrate.c
+++ b/lib/pscom/pscom_migrate.c
@@ -65,7 +65,7 @@ pscom_str_replace(char *search_str, char *replace_str, char *str)
 
 static
 int pscom_suspend_plugins(void)
-{	
+{
 	struct list_head *pos_sock;
 	struct list_head *pos_con;
 	int arch;
@@ -82,17 +82,17 @@ int pscom_suspend_plugins(void)
 		/* suspend listen FD: */
 		pscom_suspend_listen(&sock->pub);
 
-		/* iterate over all connections */
+		/* iterate over all connections and post suspend request */
 		struct list_head *tmp_con;
 		list_for_each_safe(pos_con, tmp_con, &sock->connections) {
 			pscom_con_t *con = list_entry(pos_con,
-			    			      pscom_con_t, 
+			    			      pscom_con_t,
 						      next);
-	
+
 			/* determine corresponding plugin */
 			arch = PSCOM_CON_TYPE2ARCH(con->pub.type);
 		 	plugin = pscom_plugin_by_archid(arch);
-			
+
 			/* suspend all still pending on-demand connections, too */
 			if(con->pub.type == PSCOM_CON_TYPE_ONDEMAND) {
 				con->read_suspend(con);
@@ -104,25 +104,53 @@ int pscom_suspend_plugins(void)
 				continue;
 
 			/* shutdown the connection if not migratable */
-			if (plugin->properties & 
+			if (plugin->properties &
 			    PSCOM_PLUGIN_PROP_NOT_MIGRATABLE) {
-	
-				pscom_con_shutdown(con);	
-
-				/* wait for response */
-				while ( (con->read_is_suspended == 0) || (con->write_is_suspended == 0) ) {
-					con->read_start(con);
-					con->write_start(con);
-					pscom_test_any();
-				}
+
+				DPRINT(3, "%s:%u: send REQ to %s (type: %s)",
+				       __FILE__,
+				       __LINE__,
+				       pscom_con_info_str(&con->pub.remote_con_info),
+				       pscom_con_type_str(con->pub.type));
+				pscom_con_shutdown(con);
+				list_add_tail(&con->shutdown_requested, &sock->shutdown_connections);
+
+			}
+		}
+	}
+
+	/* wait for all connections to be suspended */
+	list_for_each(pos_sock, &pscom.sockets) {
+		pscom_sock_t *sock = list_entry(pos_sock, pscom_sock_t, next);
+
+		/* iterate over all connections and post suspend request */
+		struct list_head *tmp_con;
+		list_for_each_safe(pos_con, tmp_con, &sock->shutdown_connections) {
+			pscom_con_t *con = list_entry(pos_con,
+			    			      pscom_con_t,
+						      shutdown_requested);
+
+			DPRINT(3, "%s:%u: wait for ACK from %s (type: %s)",
+			       __FILE__,
+			       __LINE__,
+			       pscom_con_info_str(&con->pub.remote_con_info),
+			       pscom_con_type_str(con->pub.type));
+
+			while ( (con->read_is_suspended == 0) || (con->write_is_suspended == 0) ) {
+				con->read_start(con);
+				con->write_start(con);
+				pscom_test_any();
 			}
+
+			list_del_init(&con->shutdown_requested);
 		}
+		assert(list_empty(&sock->shutdown_connections));
 	}
 
+
 	/*
 	 * Shutdown non-migratable plugins
 	 */
-
 	DPRINT(1, "%s %u: Find non-migratable plugins ...", __FILE__, __LINE__);
 	struct list_head *pos_plugin;
 	list_for_each(pos_plugin, &pscom_plugins) {
@@ -130,17 +158,17 @@ int pscom_suspend_plugins(void)
 
 		if ((plugin->properties & PSCOM_PLUGIN_PROP_NOT_MIGRATABLE) &&
 		    (plugin->destroy)) {
-			DPRINT(1, 
-			       "%s %u: Destroying '%s' ...", 
-			       __FILE__, 
+			DPRINT(1,
+			       "%s %u: Destroying '%s' ...",
+			       __FILE__,
 			       __LINE__,
 			       plugin->name);
 			if(plugin->destroy) {
 				plugin->destroy();
 			}
-			DPRINT(1, 
-			       "%s %u: Successfully destroyed '%s'!", 
-			       __FILE__, 
+			DPRINT(1,
+			       "%s %u: Successfully destroyed '%s'!",
+			       __FILE__,
 			       __LINE__,
 			       plugin->name);
 		}
@@ -178,10 +206,10 @@ int pscom_resume_plugins(void)
 		/* iterate over all connections */
 		list_for_each(pos_con, &sock->connections) {
 			pscom_con_t *con = list_entry(pos_con,
-			    			      pscom_con_t, 
+			    			      pscom_con_t,
 						      next);
 			/* resume connections */
-			pscom_resume_connection(&con->pub);	
+			pscom_resume_connection(&con->pub);
 		}
 	}
 
@@ -198,8 +226,8 @@ int pscom_resume_non_migratable_plugins(void)
 }
 
 static
-void pscom_message_callback(struct mosquitto *mosquitto_client, 
-    				 void *arg, 
+void pscom_message_callback(struct mosquitto *mosquitto_client,
+    				 void *arg,
 				 const struct mosquitto_message *message)
 {
 	int pid = -1;
@@ -210,11 +238,11 @@ void pscom_message_callback(struct mosquitto *mosquitto_client,
 	if ((char*)message->payload) {
 		strcpy(payload, (char*)message->payload);
 
-		if (!strcmp(payload, "*")) {
+		if (!strcmp(payload, "*") || !strcmp(payload, "resume") || !strcmp(payload, "suspend")) {
 			pid = -2;
 		} else {
 			msg = strtok(payload, " ");
-	
+
 			while (msg) {
 				sscanf(msg, "%d", &pid);
 				if (pid == my_pid)
@@ -225,7 +253,7 @@ void pscom_message_callback(struct mosquitto *mosquitto_client,
 	} else {
 		pid = -2;
 	}
-	
+
 
 	if (pid == my_pid || pid == -2) {
 
@@ -263,10 +291,10 @@ void pscom_message_callback(struct mosquitto *mosquitto_client,
 //			assert(0);
 			break;
 
-		default:	
+		default:
 			DPRINT(1, "%s %d: ERROR: Unknown migration state (%d). "
-				  "Abort!", 
-				  __FILE__, __LINE__, 
+				  "Abort!",
+				  __FILE__, __LINE__,
 				  pscom.migration_state);
 			assert(0);
 		}
@@ -298,7 +326,7 @@ void pscom_report_to_migfra(const char *status)
 		       strerror(errno));
 		exit(-1);
 	}
-	
+
 	/* reset migration state */
 	pscom.migration_state = PSCOM_MIGRATION_INACTIVE;
 }
@@ -348,11 +376,11 @@ void pscom_migration_handle_shutdown_req(void)
 				    false);
 	if (err != MOSQ_ERR_SUCCESS) {
 		fprintf(stderr, "%s %d: ERROR: Could not publish on '%s' - %d"
-		       "(%d [%s])", 
+		       "(%d [%s])",
 		       __FILE__, __LINE__,
 		       PSCOM_MOSQUITTO_RESP_TOPIC,
 		       err,
-		       errno, 
+		       errno,
 		       strerror(errno));
 		exit(-1);
 	}
@@ -362,7 +390,7 @@ void pscom_migration_handle_shutdown_req(void)
 		sched_yield();
 	}
 
-	/* resume the connections now */	
+	/* resume the connections now */
 	pscom_migration_handle_resume_req();
 }
 
@@ -373,7 +401,7 @@ int pscom_migration_init(void)
 	/* leave if feature should be disabled */
 	if (pscom.env.suspend_resume == 0)
 		return 0;
-	
+
 	/* initialize libmosquitto */
 	if (mosquitto_lib_init() != MOSQ_ERR_SUCCESS) {
 		DPRINT(1, "%s %d: ERROR: Could not init libmosquitto ",
@@ -381,24 +409,24 @@ int pscom_migration_init(void)
 		return PSCOM_ERR_STDERROR;
 	}
 
-	/* create a new mosquitto client */	
+	/* create a new mosquitto client */
 	char client_name[PSCOM_MOSQUITTO_CLIENT_NAME_LENGTH];
 	char my_pid[10];
 	sprintf(my_pid, "_%d", getpid());
 	gethostname(client_name, PSCOM_MOSQUITTO_CLIENT_NAME_LENGTH);
 	strcat(client_name, my_pid);
-	pscom_mosquitto_client = mosquitto_new(client_name, 
+	pscom_mosquitto_client = mosquitto_new(client_name,
 	    				       true,
 					       NULL);
 	if (pscom_mosquitto_client == NULL) {
 		DPRINT(1, "%s %d: ERROR: Could create new mosquitto client "
-		       "instance (%d [%s])", 
+		       "instance (%d [%s])",
 		       __FILE__, __LINE__,
-		       errno, 
+		       errno,
 		       strerror(errno));
 		return PSCOM_ERR_STDERROR;
 	}
-	
+
 	/* connect to mosquitto broker in BLOCKING manner */
 	int err;
 	err = mosquitto_connect(pscom_mosquitto_client,
@@ -407,10 +435,10 @@ int pscom_migration_init(void)
 			      	PSCOM_KEEP_ALIVE_INT);
 	if ( err != MOSQ_ERR_SUCCESS) {
 		DPRINT(1, "%s %d: ERROR: Could connect to the broker - %d"
-		       "(%d [%s])", 
+		       "(%d [%s])",
 		       __FILE__, __LINE__,
 		       err,
-		       errno, 
+		       errno,
 		       strerror(errno));
 		return PSCOM_ERR_STDERROR;
 	} else {
@@ -436,11 +464,11 @@ int pscom_migration_init(void)
 				  0);
 	if (err != MOSQ_ERR_SUCCESS) {
 		DPRINT(1, "%s %d: ERROR: Could not subscribe to '%s' - %d"
-		       "(%d [%s])", 
+		       "(%d [%s])",
 		       __FILE__, __LINE__,
 		       pscom_mosquitto_req_topic,
 		       err,
-		       errno, 
+		       errno,
 		       strerror(errno));
 		return PSCOM_ERR_STDERROR;
 	}
@@ -451,7 +479,7 @@ int pscom_migration_init(void)
 	/* set the subscription callback */
 	mosquitto_message_callback_set(pscom_mosquitto_client,
 				       &pscom_message_callback);
-	
+
 	/* start the communication loop */
 	err = mosquitto_loop_start(pscom_mosquitto_client);
 	if ( err != MOSQ_ERR_SUCCESS) {
@@ -470,17 +498,17 @@ int pscom_migration_cleanup(void)
 {
 	int err;
 
-	/* unsubscribe from the migration command topic */	
+	/* unsubscribe from the migration command topic */
 	err = mosquitto_unsubscribe(pscom_mosquitto_client,
 				    NULL,
 				    PSCOM_MOSQUITTO_REQ_TOPIC);
 	if (err != MOSQ_ERR_SUCCESS) {
 		DPRINT(1, "%s %d: ERROR: Could not unsubscribe from '%s' - %d"
-		       "(%d [%s])", 
+		       "(%d [%s])",
 		       __FILE__, __LINE__,
 		       PSCOM_MOSQUITTO_REQ_TOPIC,
 		       err,
-		       errno, 
+		       errno,
 		       strerror(errno));
 		return PSCOM_ERR_STDERROR;
 	}
@@ -506,7 +534,7 @@ int pscom_migration_cleanup(void)
 		return PSCOM_ERR_STDERROR;
 	}
 
-	/* destroy the mosquitto client */	
+	/* destroy the mosquitto client */
 	mosquitto_destroy(pscom_mosquitto_client);
 
 	/* cleanup libmosquitto */
diff --git a/lib/pscom/pscom_migrate.h b/lib/pscom/pscom_migrate.h
index 84205883..7ca4216c 100644
--- a/lib/pscom/pscom_migrate.h
+++ b/lib/pscom/pscom_migrate.h
@@ -24,7 +24,7 @@
 #define PSCOM_MOSQUITTO_TOPIC_LENGTH 		50
 #define PSCOM_MOSQUITTO_REQ_TOPIC 		"fast/pscom/<hostname>/<pid>/request"
 #define PSCOM_MOSQUITTO_RESP_TOPIC 		"fast/pscom/<hostname>/<pid>/response"
-#define PSCOM_BROKER_HOST 			"devon"
+#define PSCOM_BROKER_HOST 			"zerberus"
 #define PSCOM_BROKER_PORT 			1883
 #define PSCOM_KEEP_ALIVE_INT 			60
 
diff --git a/lib/pscom/pscom_priv.h b/lib/pscom/pscom_priv.h
index 87768b48..980e32f3 100644
--- a/lib/pscom/pscom_priv.h
+++ b/lib/pscom/pscom_priv.h
@@ -291,6 +291,8 @@ struct PSCOM_con
 	pscom_poll_reader_t	poll_reader;
 	struct list_head	poll_next_send; // used by pscom.poll_sender
 
+	struct list_head	shutdown_requested; // user by S/R protocol
+
 	struct con_guard	con_guard; // connection guard
 
 	struct {
@@ -346,6 +348,8 @@ struct PSCOM_sock
 	struct list_head	groups;		// List of pscom_group_t.next
 	struct list_head	group_req_unknown; // List of pscom_req_t.next (requests with unknown group id)
 
+	struct list_head	shutdown_connections;	// List of pscom_con_t.shutdown_requested
+
 	struct pscom_listener {
 		ufd_info_t	ufd_info;	// TCP listen for new connections
 		unsigned	usercnt;	// Count the users of the listening fd. (keep fd open, if > 0)
diff --git a/lib/pscom/pscom_sock.c b/lib/pscom/pscom_sock.c
index c05dd983..56e6ef62 100644
--- a/lib/pscom/pscom_sock.c
+++ b/lib/pscom/pscom_sock.c
@@ -154,6 +154,7 @@ pscom_sock_t *pscom_sock_create(unsigned int userdata_size)
 	INIT_LIST_HEAD(&sock->group_req_unknown);
 	INIT_LIST_HEAD(&sock->pendingioq);
 	INIT_LIST_HEAD(&sock->sendq_suspending);
+	INIT_LIST_HEAD(&sock->shutdown_connections);
 
 	sock->recv_req_cnt_any = 0;