diff --git a/MQTTSNGateway/src/MQTTSNGWBrokerRecvTask.cpp b/MQTTSNGateway/src/MQTTSNGWBrokerRecvTask.cpp
index 3b57408..7701af8 100644
--- a/MQTTSNGateway/src/MQTTSNGWBrokerRecvTask.cpp
+++ b/MQTTSNGateway/src/MQTTSNGWBrokerRecvTask.cpp
@@ -131,11 +131,19 @@ void BrokerRecvTask::run(void)
 							}
 							else
 							{
-								if ( rc == 0 )
+								if ( rc == 0 )  // Disconnected
 								{
 									client->getNetwork()->close();
 									delete packet;
-									goto nextClient;
+
+									/* delete client when the client is not authorized on & session is clean */
+									_gateway->getClientList()->erase(client);
+
+									if ( client )
+									{
+										client = client->getNextClient();
+									}
+									continue;
 								}
 								else if (rc == -1)
 								{
diff --git a/MQTTSNGateway/src/MQTTSNGWClient.cpp b/MQTTSNGateway/src/MQTTSNGWClient.cpp
index 136c51b..965e90e 100644
--- a/MQTTSNGateway/src/MQTTSNGWClient.cpp
+++ b/MQTTSNGateway/src/MQTTSNGWClient.cpp
@@ -125,30 +125,34 @@ bool ClientList::authorize(const char* fileName)
 
 void ClientList::erase(Client* client)
 {
-	_mutex.lock();
-	Client* prev = client->_prevClient;
-	Client* next = client->_nextClient;
+	if ( !_authorize && client->erasable())
+	{
+		_mutex.lock();
+		Client* prev = client->_prevClient;
+		Client* next = client->_nextClient;
 
-	if (prev)
-	{
-		prev->_nextClient = next;
-	}
-	else
-	{
-		_firstClient = next;
+		if (prev)
+		{
+			prev->_nextClient = next;
+		}
+		else
+		{
+			_firstClient = next;
 
+		}
+		if (next)
+		{
+			next->_prevClient = prev;
+		}
+		else
+		{
+			_endClient = prev;
+		}
+		_clientCnt--;
+		delete client;
+		client = 0;
+		_mutex.unlock();
 	}
-	if (next)
-	{
-		next->_prevClient = prev;
-	}
-	else
-	{
-		_endClient = prev;
-	}
-	_clientCnt--;
-	_authorize = false;
-	_mutex.unlock();
 }
 
 Client* ClientList::getClient(SensorNetAddress* addr)
@@ -280,6 +284,8 @@ Client::Client(bool secure)
 	_sensorNetype = true;
 	_connAck = 0;
 	_waitWillMsgFlg = false;
+	_sessionStatus = false;
+	_otaClient = 0;
 	_prevClient = 0;
 	_nextClient = 0;
 }
@@ -389,6 +395,16 @@ void Client::setKeepAlive(MQTTSNPacket* packet)
 	}
 }
 
+void Client::setSessionStatus(bool status)
+{
+	_sessionStatus = status;
+}
+
+bool Client::erasable(void)
+{
+	return _sessionStatus;
+}
+
 void Client::updateStatus(MQTTSNPacket* packet)
 {
 	if (((_status == Cstat_Disconnected) || (_status == Cstat_Lost)) && packet->getType() == MQTTSN_CONNECT)
diff --git a/MQTTSNGateway/src/MQTTSNGWClient.h b/MQTTSNGateway/src/MQTTSNGWClient.h
index 396ff43..c4012c7 100644
--- a/MQTTSNGateway/src/MQTTSNGWClient.h
+++ b/MQTTSNGateway/src/MQTTSNGWClient.h
@@ -271,6 +271,8 @@ public:
 	char* getWillMsg(void);
 	const char* getStatus(void);
 	void setWaitWillMsgFlg(bool);
+	void setSessionStatus(bool);  // true: clean session
+	bool erasable(void);
 
 	bool isDisconnect(void);
 	bool isActive(void);
@@ -312,6 +314,8 @@ private:
 	bool _sensorNetype;     // false: unstable network like a G3
 	SensorNetAddress _sensorNetAddr;
 
+	bool _sessionStatus;
+
 	Client* _nextClient;
 	Client* _prevClient;
 	Client* _otaClient;
diff --git a/MQTTSNGateway/src/MQTTSNGWConnectionHandler.cpp b/MQTTSNGateway/src/MQTTSNGWConnectionHandler.cpp
index 5ef17b1..3998e46 100644
--- a/MQTTSNGateway/src/MQTTSNGWConnectionHandler.cpp
+++ b/MQTTSNGateway/src/MQTTSNGWConnectionHandler.cpp
@@ -55,14 +55,14 @@ void MQTTSNConnectionHandler::handleSearchgw(MQTTSNPacket* packet)
 {
 	if (packet->getType() == MQTTSN_SEARCHGW)
 	{
-		if (_gateway->getClientList()->getClientCount() < MAX_CLIENTS)
-		{
+		//if (_gateway->getClientList()->getClientCount() < MAX_CLIENTS)
+		//{
 			MQTTSNPacket* gwinfo = new MQTTSNPacket();
 			gwinfo->setGWINFO(_gateway->getGWParams()->gatewayId);
 			Event* ev1 = new Event();
 			ev1->setBrodcastEvent(gwinfo);
 			_gateway->getClientSendQue()->post(ev1);
-		}
+		//}
 	}
 }
 
@@ -94,6 +94,7 @@ void MQTTSNConnectionHandler::handleConnect(Client* client, MQTTSNPacket* packet
 		connectData->flags.bits.username = 1;
 	}
 
+	client->setSessionStatus(false);
 	if (data.cleansession)
 	{
 		connectData->flags.bits.cleanstart = 1;
@@ -108,6 +109,7 @@ void MQTTSNConnectionHandler::handleConnect(Client* client, MQTTSNPacket* packet
 		}
 		topics = new Topics();
 		client->setTopics(topics);
+		client->setSessionStatus(true);
 	}
 
 	if (data.willFlag)