diff --git a/examples/knx-linux/CMakeLists.txt b/examples/knx-linux/CMakeLists.txt
index 169e23b..abd8ac4 100644
--- a/examples/knx-linux/CMakeLists.txt
+++ b/examples/knx-linux/CMakeLists.txt
@@ -31,7 +31,8 @@ add_executable(knx-linux
 	../../src/knx/cemi_frame.cpp
 	../../src/knx/cemi_frame.h
 	../../src/knx/cemi_server.cpp 
-	../../src/knx/cemi_server_object.cpp 
+        ../../src/knx/cemi_server.h
+        ../../src/knx/cemi_server_object.cpp
         ../../src/knx/cemi_server_object.h
         ../../src/knx/data_link_layer.cpp
 	../../src/knx/data_link_layer.h
@@ -55,14 +56,22 @@ add_executable(knx-linux
 	../../src/knx/ip_parameter_object.cpp 
 	../../src/knx/ip_parameter_object.h
 	../../src/knx/knx_ip_device_information_dib.cpp
-	../../src/knx/knx_ip_dib.cpp
-	../../src/knx/knx_ip_frame.cpp
-	../../src/knx/knx_ip_routing_indication.cpp
-	../../src/knx/knx_ip_search_request.cpp
-	../../src/knx/knx_ip_search_response.cpp
-	../../src/knx/knx_ip_supported_service_dib.cpp
-	../../src/knx/ip_host_protocol_address_information.cpp
-	../../src/knx/knx_value.cpp
+        ../../src/knx/knx_ip_device_information_dib.h
+        ../../src/knx/knx_ip_dib.cpp
+        ../../src/knx/knx_ip_dib.h
+        ../../src/knx/knx_ip_frame.cpp
+        ../../src/knx/knx_ip_frame.h
+        ../../src/knx/knx_ip_routing_indication.cpp
+        ../../src/knx/knx_ip_routing_indication.h
+        ../../src/knx/knx_ip_search_request.cpp
+        ../../src/knx/knx_ip_search_request.h
+        ../../src/knx/knx_ip_search_response.cpp
+        ../../src/knx/knx_ip_search_response.h
+        ../../src/knx/knx_ip_supported_service_dib.cpp
+        ../../src/knx/knx_ip_supported_service_dib.h
+        ../../src/knx/ip_host_protocol_address_information.cpp
+        ../../src/knx/ip_host_protocol_address_information.h
+        ../../src/knx/knx_value.cpp
 	../../src/knx/knx_value.h
 	../../src/knx/memory.cpp 
 	../../src/knx/memory.h
@@ -70,7 +79,7 @@ add_executable(knx-linux
 	../../src/knx/network_layer.h
 	../../src/knx/npdu.cpp 
 	../../src/knx/npdu.h
-    ../../src/knx/platform.cpp
+        ../../src/knx/platform.cpp
 	../../src/knx/platform.h
 	../../src/knx/property.cpp
 	../../src/knx/property.h 
@@ -93,7 +102,8 @@ add_executable(knx-linux
 	../../src/knx/transport_layer.cpp 
 	../../src/knx/transport_layer.h
 	../../src/knx/usb_tunnel_interface.cpp
-	../../src/knx_facade.cpp 
+        ../../src/knx/usb_tunnel_interface.h
+        ../../src/knx_facade.cpp
 	../../src/knx_facade.h
 	../../src/linux_platform.cpp 
 	../../src/linux_platform.h
diff --git a/src/knx/application_layer.cpp b/src/knx/application_layer.cpp
index 247cb56..7899662 100644
--- a/src/knx/application_layer.cpp
+++ b/src/knx/application_layer.cpp
@@ -77,107 +77,157 @@ void ApplicationLayer::dataGroupConfirm(AckType ack, HopCountType hopType, Prior
     }
 }
 
-void ApplicationLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu)
+void ApplicationLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu, SystemBroadcast broadcastType)
 {
     uint8_t* data = apdu.data();
-    switch (apdu.type())
+
+    if (broadcastType == Broadcast)
     {
-        case IndividualAddressWrite:
+        // APCI on Broadcast
+        switch (apdu.type())
         {
-            uint16_t newAddress;
-            popWord(newAddress, data + 1);
-            _bau.individualAddressWriteIndication(hopType, newAddress);
-            break;
+            case IndividualAddressWrite:
+            {
+                uint16_t newAddress;
+                popWord(newAddress, data + 1);
+                _bau.individualAddressWriteIndication(hopType, newAddress);
+                break;
+            }
+            case IndividualAddressRead:
+                _bau.individualAddressReadIndication(hopType);
+                break;
+            case IndividualAddressResponse:
+                _bau.individualAddressReadAppLayerConfirm(hopType, apdu.frame().sourceAddress());
+                break;
+            case IndividualAddressSerialNumberRead:
+            {
+                uint8_t* knxSerialNumber = &data[1];
+                _bau.individualAddressSerialNumberReadIndication(priority, hopType, knxSerialNumber);
+                break;
+            }
+            case IndividualAddressSerialNumberResponse:
+            {
+                uint16_t domainAddress;
+                popWord(domainAddress, data + 7);
+                _bau.individualAddressSerialNumberReadAppLayerConfirm(hopType, data + 1, apdu.frame().sourceAddress(),
+                    domainAddress);
+                break;
+            }
+            case IndividualAddressSerialNumberWrite:
+            {
+                uint8_t* knxSerialNumber = &data[1];
+                uint16_t newIndividualAddress;
+                popWord(newIndividualAddress, &data[7]);
+                _bau.individualAddressSerialNumberWriteIndication(priority, hopType, newIndividualAddress, knxSerialNumber);
+                break;
+            }
+#if !((MEDIUM_TYPE == 5) || (MEDIUM_TYPE == 0))
+            default:
+                print("Broadcast-indication: unhandled APDU-Type: ");
+                println(apdu.type());
+                break;
         }
-        case IndividualAddressRead:
-            _bau.individualAddressReadIndication(hopType);
-            break;
-        case IndividualAddressResponse:
-            _bau.individualAddressReadAppLayerConfirm(hopType, apdu.frame().sourceAddress());
-            break;
-        case IndividualAddressSerialNumberRead:
+    }
+    else if (broadcastType == SysBroadcast)
+    {
+        // APCI on SystemBroadcast
+        switch (apdu.type())
         {
-            uint8_t* knxSerialNumber = &data[1];
-            _bau.individualAddressSerialNumberReadIndication(priority, hopType, knxSerialNumber);
-            break;
-        }
-        case IndividualAddressSerialNumberResponse:
-        {
-            uint16_t domainAddress;
-            popWord(domainAddress, data + 7);
-            _bau.individualAddressSerialNumberReadAppLayerConfirm(hopType, data + 1, apdu.frame().sourceAddress(),
-                domainAddress);
-            break;
-        }
-        case IndividualAddressSerialNumberWrite:
-        {
-            uint8_t* knxSerialNumber = &data[1];
-            uint16_t newIndividualAddress;
-            popWord(newIndividualAddress, &data[7]);
-            _bau.individualAddressSerialNumberWriteIndication(priority, hopType, newIndividualAddress, knxSerialNumber);
-            break;
-        }
-        default:
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-            dataSystemBroadcastIndication(hopType, priority, source, apdu);
-#else
-            print("Broadcast-indication: unhandled APDU-Type: ");
-            println(apdu.type());
 #endif
+            // TODO: testInfo could be of any length
+            case SystemNetworkParameterRead:
+            {
+                uint16_t objectType;
+                uint16_t propertyId;
+                uint8_t testInfo[2];
+                popWord(objectType, data + 1);
+                popWord(propertyId, data + 3);
+                popByte(testInfo[0], data + 4);
+                popByte(testInfo[1], data + 5);
+                propertyId = (propertyId >> 4) & 0x0FFF;;
+                testInfo[0] &= 0x0F;
+                _bau.systemNetworkParameterReadIndication(priority, hopType, objectType, propertyId, testInfo, sizeof(testInfo));
+                break;
+            }
+            case DomainAddressSerialNumberWrite:
+            {
+                const uint8_t* knxSerialNumber = &data[1];
+                const uint8_t* domainAddress = &data[7];
+                _bau.domainAddressSerialNumberWriteIndication(priority, hopType, domainAddress, knxSerialNumber);
+                break;
+            }
+            case DomainAddressSerialNumberRead:
+            {
+                const uint8_t* knxSerialNumber = &data[1];
+                _bau.domainAddressSerialNumberReadIndication(priority, hopType, knxSerialNumber);
+                break;
+            }
+#if !((MEDIUM_TYPE == 5) || (MEDIUM_TYPE == 0))
+            default:
+                if (broadcastType == SysBroadcast)
+                {
+                    print("System");
+                }
+#endif
+                print("Broadcast-indication: unhandled APDU-Type: ");
+                println(apdu.type());
+                break;
+        }
     }
 }
 
-void ApplicationLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status)
+void ApplicationLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status, SystemBroadcast broadcastType)
 {
     uint8_t* data = apdu.data();
-    switch (apdu.type())
-    {
-        case IndividualAddressWrite:
-        {
-            uint16_t newAddress;
-            popWord(newAddress, data + 1);
-            _bau.individualAddressWriteLocalConfirm(ack, hopType, newAddress, status);
-            break;
-        }
-        case IndividualAddressRead:
-            _bau.individualAddressReadLocalConfirm(ack, hopType, status);
-            break;
-        case IndividualAddressResponse:
-            _bau.individualAddressReadResponseConfirm(ack, hopType, status);
-            break;
-        case IndividualAddressSerialNumberRead:
-            _bau.individualAddressSerialNumberReadLocalConfirm(ack, hopType, data + 1, status);
-            break;
-        case IndividualAddressSerialNumberResponse:
-        {
-            uint16_t domainAddress;
-            popWord(domainAddress, data + 7);
-            _bau.individualAddressSerialNumberReadResponseConfirm(ack, hopType, data + 1, domainAddress, status);
-            break;
-        }
-        case IndividualAddressSerialNumberWrite:
-        {
-            uint16_t newAddress;
-            popWord(newAddress, data + 7);
-            _bau.individualAddressSerialNumberWriteLocalConfirm(ack, hopType, data + 1, newAddress, status);
-            break;
-        }
-        default:
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-            dataSystemBroadcastConfirm(hopType, priority, apdu, status);
-#else
-            print("Broadcast-confirm: unhandled APDU-Type: ");
-            println(apdu.type());
-#endif
-    }
-}
 
-void ApplicationLayer::dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu)
-{
-    const uint8_t* data = apdu.data();
-    switch (apdu.type())
+    if (broadcastType == Broadcast)
     {
-        // TODO: testInfo could be of any length
+        // APCI on Broadcast
+        switch (apdu.type())
+        {
+            case IndividualAddressWrite:
+            {
+                uint16_t newAddress;
+                popWord(newAddress, data + 1);
+                _bau.individualAddressWriteLocalConfirm(ack, hopType, newAddress, status);
+                break;
+            }
+            case IndividualAddressRead:
+                _bau.individualAddressReadLocalConfirm(ack, hopType, status);
+                break;
+            case IndividualAddressResponse:
+                _bau.individualAddressReadResponseConfirm(ack, hopType, status);
+                break;
+            case IndividualAddressSerialNumberRead:
+                _bau.individualAddressSerialNumberReadLocalConfirm(ack, hopType, data + 1, status);
+                break;
+            case IndividualAddressSerialNumberResponse:
+            {
+                uint16_t domainAddress;
+                popWord(domainAddress, data + 7);
+                _bau.individualAddressSerialNumberReadResponseConfirm(ack, hopType, data + 1, domainAddress, status);
+                break;
+            }
+            case IndividualAddressSerialNumberWrite:
+            {
+                uint16_t newAddress;
+                popWord(newAddress, data + 7);
+                _bau.individualAddressSerialNumberWriteLocalConfirm(ack, hopType, data + 1, newAddress, status);
+                break;
+            }
+#if !((MEDIUM_TYPE == 5) || (MEDIUM_TYPE == 0))
+            default:
+                print("Broadcast-confirm: unhandled APDU-Type: ");
+                println(apdu.type());
+                break;
+        }
+    }
+    else if (broadcastType == SysBroadcast)
+    {
+        // APCI on SystemBroadcast
+        switch (apdu.type())
+        {
+#endif
         case SystemNetworkParameterRead:
         {
             uint16_t objectType;
@@ -189,79 +239,33 @@ void ApplicationLayer::dataSystemBroadcastIndication(HopCountType hopType, Prior
             popByte(testInfo[1], data + 5);
             propertyId = (propertyId >> 4) & 0x0FFF;;
             testInfo[0] &= 0x0F;
-            _bau.systemNetworkParameterReadIndication(priority, hopType, objectType, propertyId, testInfo, sizeof(testInfo));
+            //TODO: _bau.systemNetworkParameterReadLocalConfirm(priority, hopType, objectType, propertyId, testInfo, sizeof(testInfo), status);
             break;
         }
         case DomainAddressSerialNumberWrite:
         {
             const uint8_t* knxSerialNumber = &data[1];
             const uint8_t* domainAddress = &data[7];
-            _bau.domainAddressSerialNumberWriteIndication(priority, hopType, domainAddress, knxSerialNumber);
+            //TODO: _bau.domainAddressSerialNumberWriteLocalConfirm(priority, hopType, domainAddress, knxSerialNumber, status);
             break;
         }
         case DomainAddressSerialNumberRead:
         {
             const uint8_t* knxSerialNumber = &data[1];
-            _bau.domainAddressSerialNumberReadIndication(priority, hopType, knxSerialNumber);
+            //TODO: _bau.domainAddressSerialNumberReadLocalConfirm(priority, hopType, knxSerialNumber, status);
             break;
         }
         default:
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-        // For closed media
-        print("Broadcast-indication: unhandled APDU-Type: ");
-        println(apdu.type());
-#else
-        // For open media (e.g. PL, RF)
-        print("SystemBroadcast-indication: unhandled APDU-Type: ");
-        println(apdu.type());
-#endif
-            break;
-    }
-}
-
-void ApplicationLayer::dataSystemBroadcastConfirm(HopCountType hopType, Priority priority, APDU& apdu, bool status)
-{
-    const uint8_t* data = apdu.data();
-    switch (apdu.type())
-    {
-    case SystemNetworkParameterRead:
-    {
-        uint16_t objectType;
-        uint16_t propertyId;
-        uint8_t testInfo[2];
-        popWord(objectType, data + 1);
-        popWord(propertyId, data + 3);
-        popByte(testInfo[0], data + 4);
-        popByte(testInfo[1], data + 5);
-        propertyId = (propertyId >> 4) & 0x0FFF;;
-        testInfo[0] &= 0x0F;
-        //TODO: _bau.systemNetworkParameterReadLocalConfirm(priority, hopType, objectType, propertyId, testInfo, sizeof(testInfo), status);
-        break;
-    }
-    case DomainAddressSerialNumberWrite:
-    {
-        const uint8_t* knxSerialNumber = &data[1];
-        const uint8_t* domainAddress = &data[7];
-        //TODO: _bau.domainAddressSerialNumberWriteLocalConfirm(priority, hopType, domainAddress, knxSerialNumber, status);
-        break;
-    }
-    case DomainAddressSerialNumberRead:
-    {
-        const uint8_t* knxSerialNumber = &data[1];
-        //TODO: _bau.domainAddressSerialNumberReadLocalConfirm(priority, hopType, knxSerialNumber, status);
-        break;
-    }
-    default:
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-        // For closed media
-        print("Broadcast-confirm: unhandled APDU-Type: ");
-        println(apdu.type());
-#else
-        // For open media (e.g. PL, RF)
-        print("SystemBroadcast-confirm: unhandled APDU-Type: ");
-        println(apdu.type());
+#if !((MEDIUM_TYPE == 5) || (MEDIUM_TYPE == 0))
+                if (broadcastType == SysBroadcast)
+                {
+                    print("System");
+                }
 #endif
+            print("Broadcast-confirm: unhandled APDU-Type: ");
+            println(apdu.type());
             break;
+        }
     }
 }
 
@@ -553,7 +557,7 @@ void ApplicationLayer::propertyValueWriteRequest(AckType ack, Priority priority,
 }
 
 void ApplicationLayer::functionPropertyStateResponse(AckType ack, Priority priority, HopCountType hopType, uint16_t asap,
-                                                     uint8_t objectIndex, uint8_t propertyId, uint8_t returnCode, uint8_t* resultData, uint8_t resultLength)
+                                                     uint8_t objectIndex, uint8_t propertyId, uint8_t* resultData, uint8_t resultLength)
 {
     CemiFrame frame(3 + resultLength + 1);
     APDU& apdu = frame.apdu();
@@ -562,9 +566,8 @@ void ApplicationLayer::functionPropertyStateResponse(AckType ack, Priority prior
 
     data[0] = objectIndex;
     data[1] = propertyId;
-    data[2] = returnCode;
     if (resultLength > 0)
-        memcpy(&data[3], resultData, resultLength);
+        memcpy(&data[2], resultData, resultLength);
 
     if (asap == _connectedTsap)
         dataConnectedRequest(asap, priority, apdu);
@@ -1011,11 +1014,11 @@ void ApplicationLayer::dataGroupRequest(AckType ack, HopCountType hopType, Prior
 }
 void ApplicationLayer::dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu)
 {
-    _transportLayer->dataBroadcastRequest(ack, hopType, SystemPriority, apdu);
+    _transportLayer->dataBroadcastRequest(ack, hopType, SystemPriority, apdu, Broadcast);
 }
 void ApplicationLayer::dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu)
 {
-    _transportLayer->dataSystemBroadcastRequest(AckDontCare, hopType, SystemPriority, apdu);
+    _transportLayer->dataBroadcastRequest(ack, hopType, SystemPriority, apdu, SysBroadcast);
 }
 void ApplicationLayer::dataIndividualRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t destination, APDU& apdu)
 {
diff --git a/src/knx/application_layer.h b/src/knx/application_layer.h
index ba35f2c..1b66f72 100644
--- a/src/knx/application_layer.h
+++ b/src/knx/application_layer.h
@@ -65,10 +65,8 @@ class ApplicationLayer
      */
     virtual void dataGroupConfirm(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap,
                           APDU& apdu, bool status);
-    virtual void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu);
-    virtual void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status);
-    virtual void dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu);
-    virtual void dataSystemBroadcastConfirm(HopCountType hopType, Priority priority, APDU& apdu, bool status);
+    virtual void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu, SystemBroadcast broadcastType);
+    virtual void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status, SystemBroadcast broadcastType);
     virtual void dataIndividualIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu);
     virtual void dataIndividualConfirm(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu, bool status);
     virtual void connectIndication(uint16_t tsap);
@@ -106,7 +104,7 @@ class ApplicationLayer
     void propertyValueWriteRequest(AckType ack, Priority priority, HopCountType hopType, uint16_t asap, uint8_t objectIndex,
                                    uint8_t propertyId, uint8_t numberOfElements, uint16_t startIndex, uint8_t* data, uint8_t length);
     void functionPropertyStateResponse(AckType ack, Priority priority, HopCountType hopType, uint16_t asap,
-                                       uint8_t objectIndex, uint8_t propertyId, uint8_t returnCode, uint8_t *data, uint8_t length);
+                                       uint8_t objectIndex, uint8_t propertyId, uint8_t *resultData, uint8_t resultLength);
     void propertyDescriptionReadRequest(AckType ack, Priority priority, HopCountType hopType, uint16_t asap,
                                         uint8_t objectIndex, uint8_t propertyId, uint8_t propertyIndex);
     void propertyDescriptionReadResponse(AckType ack, Priority priority, HopCountType hopType, uint16_t asap,
diff --git a/src/knx/bau07B0.cpp b/src/knx/bau07B0.cpp
index 06c394a..a4551e5 100644
--- a/src/knx/bau07B0.cpp
+++ b/src/knx/bau07B0.cpp
@@ -20,6 +20,9 @@ Bau07B0::Bau07B0(Platform& platform)
     _dlLayer.cemiServer(_cemiServer);
     _memory.addSaveRestore(&_cemiServerObject);
 #endif
+#ifdef USE_DATASECURE
+    _memory.addSaveRestore(&_secIfObj);
+#endif
 
     // Set Mask Version in Device Object depending on the BAU
     _deviceObj.maskVersion(0x07B0);
@@ -33,7 +36,12 @@ Bau07B0::Bau07B0(Platform& platform)
     prop->write(3, OT_ASSOC_TABLE);
     prop->write(4, OT_GRP_OBJ_TABLE);
     prop->write(5, OT_APPLICATION_PROG);
-#ifdef USE_CEMI_SERVER
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+    prop->write(6, OT_SECURITY);
+    prop->write(7, OT_CEMI_SERVER);
+#elif defined(USE_DATASECURE)
+    prop->write(6, OT_SECURITY);
+#elif defined(USE_CEMI_SERVER)
     prop->write(6, OT_CEMI_SERVER);
 #endif
 }
@@ -54,10 +62,18 @@ InterfaceObject* Bau07B0::getInterfaceObject(uint8_t idx)
             return &_appProgram;
         case 5: // would be app_program 2
             return nullptr;
-#ifdef USE_CEMI_SERVER
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+        case 6:
+            return &_secIfObj;
+        case 7:
+            return &_cemiServerObject;
+#elif defined(USE_CEMI_SERVER)
         case 6:
             return &_cemiServerObject;
-#endif                        
+#elif defined(USE_DATASECURE)
+        case 6:
+            return &_secIfObj;
+#endif
         default:
             return nullptr;
     }
@@ -81,6 +97,10 @@ InterfaceObject* Bau07B0::getInterfaceObject(ObjectType objectType, uint8_t obje
             return &_groupObjTable;
         case OT_APPLICATION_PROG:
             return &_appProgram;
+#ifdef USE_DATASECURE
+        case OT_SECURITY:
+            return &_secIfObj;
+#endif
 #ifdef USE_CEMI_SERVER
         case OT_CEMI_SERVER:
             return &_cemiServerObject;
@@ -103,4 +123,4 @@ void Bau07B0::loop()
 #endif    
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/knx/bau27B0.cpp b/src/knx/bau27B0.cpp
index 9ed25da..60f1b16 100644
--- a/src/knx/bau27B0.cpp
+++ b/src/knx/bau27B0.cpp
@@ -20,6 +20,9 @@ Bau27B0::Bau27B0(Platform& platform)
     _dlLayer.cemiServer(_cemiServer);
     _memory.addSaveRestore(&_cemiServerObject);
 #endif
+#ifdef USE_DATASECURE
+    _memory.addSaveRestore(&_secIfObj);
+#endif
 
     // Set Mask Version in Device Object depending on the BAU
     _deviceObj.maskVersion(0x27B0);
@@ -41,7 +44,12 @@ Bau27B0::Bau27B0(Platform& platform)
     prop->write(4, OT_GRP_OBJ_TABLE);
     prop->write(5, OT_APPLICATION_PROG);
     prop->write(6, OT_RF_MEDIUM);
-#ifdef USE_CEMI_SERVER
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+    prop->write(7, OT_SECURITY);
+    prop->write(8, OT_CEMI_SERVER);
+#elif defined(USE_DATASECURE)
+    prop->write(7, OT_SECURITY);
+#elif defined(USE_CEMI_SERVER)
     prop->write(7, OT_CEMI_SERVER);
 #endif
 }
@@ -65,10 +73,18 @@ InterfaceObject* Bau27B0::getInterfaceObject(uint8_t idx)
             return nullptr;
         case 6:
             return &_rfMediumObj;
-#ifdef USE_CEMI_SERVER
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+        case 7:
+            return &_secIfObj;
+        case 8:
+            return &_cemiServerObject;
+#elif defined(USE_CEMI_SERVER)
         case 7:
             return &_cemiServerObject;
-#endif            
+#elif defined(USE_DATASECURE)
+        case 7:
+            return &_secIfObj;
+#endif
         default:
             return nullptr;
     }
@@ -94,6 +110,10 @@ InterfaceObject* Bau27B0::getInterfaceObject(ObjectType objectType, uint8_t obje
             return &_appProgram;
         case OT_RF_MEDIUM:
             return &_rfMediumObj;
+#ifdef USE_DATASECURE
+        case OT_SECURITY:
+            return &_secIfObj;
+#endif
 #ifdef USE_CEMI_SERVER
         case OT_CEMI_SERVER:
             return &_cemiServerObject;
diff --git a/src/knx/bau57B0.cpp b/src/knx/bau57B0.cpp
index 94145c7..60695f0 100644
--- a/src/knx/bau57B0.cpp
+++ b/src/knx/bau57B0.cpp
@@ -22,6 +22,9 @@ Bau57B0::Bau57B0(Platform& platform)
     _cemiServer.dataLinkLayer(_dlLayer);
     _dlLayer.cemiServer(_cemiServer);
     _memory.addSaveRestore(&_cemiServerObject);
+#endif
+#ifdef USE_DATASECURE
+    _memory.addSaveRestore(&_secIfObj);
 #endif
     _memory.addSaveRestore(&_ipParameters);
 
@@ -38,7 +41,12 @@ Bau57B0::Bau57B0(Platform& platform)
     prop->write(4, OT_GRP_OBJ_TABLE);
     prop->write(5, OT_APPLICATION_PROG);
     prop->write(6, OT_IP_PARAMETER);
-#ifdef USE_CEMI_SERVER
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+    prop->write(7, OT_SECURITY);
+    prop->write(8, OT_CEMI_SERVER);
+#elif defined(USE_DATASECURE)
+    prop->write(7, OT_SECURITY);
+#elif defined(USE_CEMI_SERVER)
     prop->write(7, OT_CEMI_SERVER);
 #endif
 }
@@ -61,6 +69,18 @@ InterfaceObject* Bau57B0::getInterfaceObject(uint8_t idx)
             return nullptr;
         case 6:
             return &_ipParameters;
+#if defined(USE_DATASECURE) && defined(USE_CEMI_SERVER)
+        case 7:
+            return &_secIfObj;
+        case 8:
+            return &_cemiServerObject;
+#elif defined(USE_CEMI_SERVER)
+        case 7:
+            return &_cemiServerObject;
+#elif defined(USE_DATASECURE)
+        case 7:
+            return &_secIfObj;
+#endif
         default:
             return nullptr;
     }
@@ -86,6 +106,14 @@ InterfaceObject* Bau57B0::getInterfaceObject(ObjectType objectType, uint8_t obje
             return &_appProgram;
         case OT_IP_PARAMETER:
             return &_ipParameters;
+#ifdef USE_DATASECURE
+        case OT_SECURITY:
+            return &_secIfObj;
+#endif
+#ifdef USE_CEMI_SERVER
+        case OT_CEMI_SERVER:
+            return &_cemiServerObject;
+#endif
         default:
             return nullptr;
     }
@@ -96,4 +124,4 @@ DataLinkLayer& Bau57B0::dataLinkLayer()
     return _dlLayer;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/knx/bau_systemB.cpp b/src/knx/bau_systemB.cpp
index 390c97f..f3cc234 100644
--- a/src/knx/bau_systemB.cpp
+++ b/src/knx/bau_systemB.cpp
@@ -243,29 +243,27 @@ void BauSystemB::propertyValueReadIndication(Priority priority, HopCountType hop
 void BauSystemB::functionPropertyCommandIndication(Priority priority, HopCountType hopType, uint16_t asap, uint8_t objectIndex,
                                                    uint8_t propertyId, uint8_t* data, uint8_t length)
 {
-    uint8_t returnCode = 0xFF;
     uint8_t resultLength = 0;
     uint8_t resultData[32];
 
     InterfaceObject* obj = getInterfaceObject(objectIndex);
     if(obj)
-        returnCode = obj->command((PropertyID)propertyId, data, length, resultData, resultLength);
+        obj->command((PropertyID)propertyId, data, length, resultData, resultLength);
 
-    _appLayer.functionPropertyStateResponse(AckRequested, priority, hopType, asap, objectIndex, propertyId, returnCode, resultData, resultLength);
+    _appLayer.functionPropertyStateResponse(AckRequested, priority, hopType, asap, objectIndex, propertyId, resultData, resultLength);
 }
 
 void BauSystemB::functionPropertyStateIndication(Priority priority, HopCountType hopType, uint16_t asap, uint8_t objectIndex,
                                                  uint8_t propertyId, uint8_t* data, uint8_t length)
 {
-    uint8_t returnCode = 0xFF;
     uint8_t resultLength = 0;
     uint8_t resultData[32];
 
     InterfaceObject* obj = getInterfaceObject(objectIndex);
     if(obj)
-        returnCode = obj->state((PropertyID)propertyId, data, length, resultData, resultLength);
+        obj->state((PropertyID)propertyId, data, length, resultData, resultLength);
 
-    _appLayer.functionPropertyStateResponse(AckRequested, priority, hopType, asap, objectIndex, propertyId, returnCode, resultData, resultLength);
+    _appLayer.functionPropertyStateResponse(AckRequested, priority, hopType, asap, objectIndex, propertyId, resultData, resultLength);
 }
 
 void BauSystemB::individualAddressReadIndication(HopCountType hopType)
diff --git a/src/knx/bau_systemB.h b/src/knx/bau_systemB.h
index a984088..69c91de 100644
--- a/src/knx/bau_systemB.h
+++ b/src/knx/bau_systemB.h
@@ -6,6 +6,7 @@
 #include "address_table_object.h"
 #include "association_table_object.h"
 #include "group_object_table_object.h"
+#include "security_interface_object.h"
 #include "application_program_object.h"
 #include "application_layer.h"
 #include "secure_application_layer.h"
@@ -98,6 +99,7 @@ class BauSystemB : protected BusAccessUnit
     Platform& _platform;
 #ifdef USE_DATASECURE
     SecureApplicationLayer _appLayer;
+    SecurityInterfaceObject _secIfObj;
 #else
     ApplicationLayer _appLayer;
 #endif
diff --git a/src/knx/data_link_layer.cpp b/src/knx/data_link_layer.cpp
index 4130f51..fb371a6 100644
--- a/src/knx/data_link_layer.cpp
+++ b/src/knx/data_link_layer.cpp
@@ -41,14 +41,15 @@ void DataLinkLayer::dataRequest(AckType ack, AddressType addrType, uint16_t dest
     sendTelegram(npdu, ack, destinationAddr, addrType, format, priority, Broadcast);
 }
 
-void DataLinkLayer::systemBroadcastRequest(AckType ack, FrameFormat format, Priority priority, NPDU& npdu)
+void DataLinkLayer::broadcastRequest(AckType ack, FrameFormat format, Priority priority, NPDU& npdu, SystemBroadcast broadcastType)
 {
     // System Broadcast requests will always be transmitted as broadcast with KNX serial number for open media (e.g. RF medium) 
     // See 3.2.5 p.22
 #if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
+    (void)broadcastType; // not used on TP/IP, always normal broadcast
     sendTelegram(npdu, ack, 0, GroupAddress, format, priority, Broadcast);
 #else
-    sendTelegram(npdu, ack, 0, GroupAddress, format, priority, SysBroadcast);
+    sendTelegram(npdu, ack, 0, GroupAddress, format, priority, broadcastType);
 #endif
 }
 
@@ -64,7 +65,7 @@ void DataLinkLayer::dataConReceived(CemiFrame& frame, bool success)
     FrameFormat type = frame.frameType();
     Priority priority = frame.priority();
     NPDU& npdu = frame.npdu();
-    SystemBroadcast systemBroadcast = frame.systemBroadcast();
+    SystemBroadcast broadcastType = frame.systemBroadcast();
 
 #ifdef USE_CEMI_SERVER
     // if the confirmation was caused by a tunnel request then
@@ -78,15 +79,11 @@ void DataLinkLayer::dataConReceived(CemiFrame& frame, bool success)
 
     if (addrType == GroupAddress && destination == 0)
     {
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-        (void) systemBroadcast; // not used
-        _networkLayer.broadcastConfirm(ack, type, priority, source, npdu, success);
-#else
-        if (systemBroadcast == SysBroadcast)
-            _networkLayer.systemBroadcastConfirm(ack, type, priority, source, npdu, success);
-        else
-            _networkLayer.broadcastConfirm(ack, type, priority, source, npdu, success);
-#endif
+        _networkLayer.broadcastConfirm(ack, type, priority, source, npdu, success, broadcastType);
+    }
+    else if (addrType == InduvidualAddress && destination == 0)
+    {
+        _networkLayer.broadcastConfirm(ack, type, priority, source, npdu, success, broadcastType);
     }
     else
         _networkLayer.dataConfirm(ack, addrType, destination, type, priority, source, npdu, success);
@@ -104,7 +101,7 @@ void DataLinkLayer::frameRecieved(CemiFrame& frame)
     Priority priority = frame.priority();
     NPDU& npdu = frame.npdu();
     uint16_t ownAddr = _deviceObject.induvidualAddress();
-    SystemBroadcast systemBroadcast = frame.systemBroadcast();
+    SystemBroadcast broadcastType = frame.systemBroadcast();
 
 #ifdef USE_CEMI_SERVER
     // Do not send our own message back to the tunnel
@@ -119,15 +116,11 @@ void DataLinkLayer::frameRecieved(CemiFrame& frame)
 
     if (addrType == GroupAddress && destination == 0)
     {
-#if (MEDIUM_TYPE == 5)||(MEDIUM_TYPE == 0)
-        (void) systemBroadcast; // not used
-        _networkLayer.broadcastIndication(ack, type, npdu, priority, source);
-#else
-        if (systemBroadcast == SysBroadcast)
-            _networkLayer.systemBroadcastIndication(ack, type, npdu, priority, source);
-        else
-            _networkLayer.broadcastIndication(ack, type, npdu, priority, source);
-#endif
+        _networkLayer.broadcastIndication(ack, type, npdu, priority, source, broadcastType);
+    }
+    else if (addrType == InduvidualAddress && destination == 0)
+    {
+        _networkLayer.broadcastIndication(ack, type, npdu, priority, source, broadcastType);
     }
     else
     {
@@ -147,7 +140,7 @@ void DataLinkLayer::frameRecieved(CemiFrame& frame)
     }
 }
 
-bool DataLinkLayer::sendTelegram(NPDU & npdu, AckType ack, uint16_t destinationAddr, AddressType addrType, FrameFormat format, Priority priority, SystemBroadcast systemBroadcast)
+bool DataLinkLayer::sendTelegram(NPDU & npdu, AckType ack, uint16_t destinationAddr, AddressType addrType, FrameFormat format, Priority priority, SystemBroadcast broadcastType)
 {
     CemiFrame& frame = npdu.frame();
     frame.messageCode(L_data_ind);
@@ -156,7 +149,7 @@ bool DataLinkLayer::sendTelegram(NPDU & npdu, AckType ack, uint16_t destinationA
     frame.addressType(addrType);
     frame.priority(priority);
     frame.repetition(RepititionAllowed);
-    frame.systemBroadcast(systemBroadcast);
+    frame.systemBroadcast(broadcastType);
 
     if (npdu.octetCount() <= 15)
         frame.frameType(StandardFrame);
diff --git a/src/knx/data_link_layer.h b/src/knx/data_link_layer.h
index 28ba679..769c267 100644
--- a/src/knx/data_link_layer.h
+++ b/src/knx/data_link_layer.h
@@ -24,7 +24,7 @@ class DataLinkLayer
     // from network layer
     void dataRequest(AckType ack, AddressType addrType, uint16_t destinationAddr, FrameFormat format,
                      Priority priority, NPDU& npdu);
-    void systemBroadcastRequest(AckType ack, FrameFormat format, Priority priority, NPDU& npdu);
+    void broadcastRequest(AckType ack, FrameFormat format, Priority priority, NPDU& npdu, SystemBroadcast broadcastType);
     virtual void loop() = 0;
     virtual void enabled(bool value) = 0;
     virtual bool enabled() const = 0;
@@ -32,7 +32,7 @@ class DataLinkLayer
   protected:
     void frameRecieved(CemiFrame& frame);
     void dataConReceived(CemiFrame& frame, bool success);
-    bool sendTelegram(NPDU& npdu, AckType ack, uint16_t destinationAddr, AddressType addrType, FrameFormat format, Priority priority, SystemBroadcast systemBroadcast);
+    bool sendTelegram(NPDU& npdu, AckType ack, uint16_t destinationAddr, AddressType addrType, FrameFormat format, Priority priority, SystemBroadcast broadcastType);
     virtual bool sendFrame(CemiFrame& frame) = 0;
     uint8_t* frameData(CemiFrame& frame);
     DeviceObject& _deviceObject;
diff --git a/src/knx/function_property.h b/src/knx/function_property.h
index 97be948..b43df9f 100644
--- a/src/knx/function_property.h
+++ b/src/knx/function_property.h
@@ -8,8 +8,8 @@ template <class T> class FunctionProperty : public Property
 {
   public:
     FunctionProperty(T* io, PropertyID id, uint8_t access,
-                     uint8_t (*commandCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&),
-                     uint8_t (*stateCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&))
+                     void (*commandCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&),
+                     void (*stateCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&))
         : Property(id, false, PDT_FUNCTION, 1, access), _interfaceObject(io), _commandCallback(commandCallback), _stateCallback(stateCallback)
         /* max_elements is set to 1, see 3.3.7 Application Layer p.68 */
     {}
@@ -24,24 +24,28 @@ template <class T> class FunctionProperty : public Property
         return 0;
     }
 
-    virtual uint8_t command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) override
+    virtual void command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) override
     {
         if (length == 0 || _commandCallback == nullptr )
-            return 0xFF;
-
-        return _commandCallback(_interfaceObject, data, length, resultData, resultLength);
+        {
+            resultLength = 0;
+            return;
+        }
+        _commandCallback(_interfaceObject, data, length, resultData, resultLength);
     }
 
-    virtual uint8_t state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) override
+    virtual void state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) override
     {
         if (length == 0 || _stateCallback == nullptr )
-            return 0xFF;
-
-        return _stateCallback(_interfaceObject, data, length, resultData, resultLength);
+        {
+            resultLength = 0;
+            return;
+        }
+        _stateCallback(_interfaceObject, data, length, resultData, resultLength);
     }
 
   private:
     T* _interfaceObject = nullptr;
-    uint8_t (*_commandCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&) = nullptr;
-    uint8_t (*_stateCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&) = nullptr;
+    void (*_commandCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&) = nullptr;
+    void (*_stateCallback)(T*, uint8_t*, uint8_t, uint8_t*, uint8_t&) = nullptr;
 };
diff --git a/src/knx/interface_object.cpp b/src/knx/interface_object.cpp
index 1eaaf16..19396ac 100644
--- a/src/knx/interface_object.cpp
+++ b/src/knx/interface_object.cpp
@@ -137,26 +137,28 @@ uint8_t InterfaceObject::propertySize(PropertyID id)
     return prop->ElementSize();
 }
 
-uint8_t InterfaceObject::command(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength)
+void InterfaceObject::command(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength)
 {
     Property* prop = property(id);
     if (prop == nullptr)
     {
-        return 0xFF;
+        resultLength = 0;
+        return;;
     }
 
-    return prop->command(data, length, resultData, resultLength);
+    prop->command(data, length, resultData, resultLength);
 }
 
-uint8_t InterfaceObject::state(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t resultLength)
+void InterfaceObject::state(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t resultLength)
 {
     Property* prop = property(id);
     if (prop == nullptr)
     {
-        return 0xFF;
+        resultLength = 0;
+        return;;
     }
 
-    return prop->state(data, length, resultData, resultLength);
+    prop->state(data, length, resultData, resultLength);
 }
 
 uint8_t InterfaceObject::propertyDescriptionCount()
diff --git a/src/knx/interface_object.h b/src/knx/interface_object.h
index fedac54..9e8abac 100644
--- a/src/knx/interface_object.h
+++ b/src/knx/interface_object.h
@@ -114,7 +114,7 @@ class InterfaceObject : public SaveRestore
      *
      * @param[out] resultData The result data for the function
      */
-    virtual uint8_t command(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t &resultLength);
+    virtual void command(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t &resultLength);
     /**
      * Get state of a function property of the interface object. Property type must be PDT_FUNCTION
      *
@@ -128,7 +128,7 @@ class InterfaceObject : public SaveRestore
      *
      * @param[out] resultData The result data for the function
      */
-    virtual uint8_t state(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t resultLength);
+    virtual void state(PropertyID id, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t resultLength);
     /**
      * Read the Description of a property of the interface object. The output parameters are only valid if nuberOfElements is not zero.
      * 
diff --git a/src/knx/network_layer.cpp b/src/knx/network_layer.cpp
index ffea9d3..df53a17 100644
--- a/src/knx/network_layer.cpp
+++ b/src/knx/network_layer.cpp
@@ -43,9 +43,10 @@ void NetworkLayer::dataIndication(AckType ack, AddressType addrType, uint16_t de
         _transportLayer.dataGroupIndication(destination, hopType, priority, source, npdu.tpdu());
         return;
     }
-    // destination == 0
-    _transportLayer.dataBroadcastIndication(hopType, priority, source, npdu.tpdu());
 
+    // assert: programming error
+    // should never be reached!
+    // destination == 0 && (addrType == InduvidualAddress || ddrType == GroupAddress)
 }
 
 void NetworkLayer::dataConfirm(AckType ack, AddressType addressType, uint16_t destination, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status)
@@ -62,32 +63,22 @@ void NetworkLayer::dataConfirm(AckType ack, AddressType addressType, uint16_t de
         _transportLayer.dataGroupConfirm(ack, source, destination, hopType, priority, npdu.tpdu(), status);
         return;
     }
-    // destination == 0
-    _transportLayer.dataBroadcastConfirm(ack, hopType, priority, npdu.tpdu(), status);
+
+    // assert: programming error
+    // should never be reached!
+    // destination == 0 && (addrType == InduvidualAddress || ddrType == GroupAddress)
 }
 
-void NetworkLayer::broadcastIndication(AckType ack, FrameFormat format, NPDU& npdu, Priority priority, uint16_t source)
+void NetworkLayer::broadcastIndication(AckType ack, FrameFormat format, NPDU& npdu, Priority priority, uint16_t source, SystemBroadcast broadcastType)
 {
     HopCountType hopType = npdu.hopCount() == 7 ? UnlimitedRouting : NetworkLayerParameter;
-    _transportLayer.dataBroadcastIndication(hopType, priority, source, npdu.tpdu());
+    _transportLayer.dataBroadcastIndication(hopType, priority, source, npdu.tpdu(), broadcastType);
 }
 
-void NetworkLayer::broadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status)
+void NetworkLayer::broadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status, SystemBroadcast broadcastType)
 {
     HopCountType hopType = npdu.hopCount() == 7 ? UnlimitedRouting : NetworkLayerParameter;
-    _transportLayer.dataBroadcastConfirm(ack, hopType, priority, npdu.tpdu(), status);
-}
-
-void NetworkLayer::systemBroadcastIndication(AckType ack, FrameFormat format, NPDU& npdu, Priority priority, uint16_t source)
-{
-    HopCountType hopType = npdu.hopCount() == 7 ? UnlimitedRouting : NetworkLayerParameter;
-    _transportLayer.dataSystemBroadcastIndication(hopType, priority, source, npdu.tpdu());
-}
-
-void NetworkLayer::systemBroadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status)
-{
-    HopCountType hopType = npdu.hopCount() == 7 ? UnlimitedRouting : NetworkLayerParameter;
-    _transportLayer.dataSystemBroadcastConfirm(ack, hopType, npdu.tpdu(), priority, status);
+    _transportLayer.dataBroadcastConfirm(ack, hopType, priority, npdu.tpdu(), status, broadcastType);
 }
 
 void NetworkLayer::dataIndividualRequest(AckType ack, uint16_t destination, HopCountType hopType, Priority priority, TPDU& tpdu)
@@ -119,12 +110,7 @@ void NetworkLayer::dataGroupRequest(AckType ack, uint16_t destination, HopCountT
     sendDataRequest(tpdu, hopType, ack, destination, priority, GroupAddress);
 }
 
-void NetworkLayer::dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu)
-{
-    sendDataRequest(tpdu, hopType, ack, 0, priority, GroupAddress);
-}
-
-void NetworkLayer::dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu)
+void NetworkLayer::dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, SystemBroadcast broadcastType)
 {
     NPDU& npdu = tpdu.frame().npdu();
 
@@ -135,5 +121,5 @@ void NetworkLayer::dataSystemBroadcastRequest(AckType ack, HopCountType hopType,
 
     FrameFormat frameFormat = npdu.octetCount() > 15 ? ExtendedFrame : StandardFrame;
 
-    _dataLinkLayer->systemBroadcastRequest(ack, frameFormat, priority, npdu);
+    _dataLinkLayer->broadcastRequest(ack, frameFormat, priority, npdu, broadcastType);
 }
diff --git a/src/knx/network_layer.h b/src/knx/network_layer.h
index 0b1f88e..17441dd 100644
--- a/src/knx/network_layer.h
+++ b/src/knx/network_layer.h
@@ -21,17 +21,14 @@ class NetworkLayer
     void dataConfirm(AckType ack, AddressType addressType, uint16_t destination, FrameFormat format, Priority priority,
                      uint16_t source, NPDU& npdu, bool status);
     void broadcastIndication(AckType ack, FrameFormat format, NPDU& npdu,
-                             Priority priority, uint16_t source);
-    void broadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status);
-    void systemBroadcastIndication(AckType ack, FrameFormat format, NPDU& npdu,
-                                   Priority priority, uint16_t source);
-    void systemBroadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status);
+                             Priority priority, uint16_t source, SystemBroadcast broadcastType);
+    void broadcastConfirm(AckType ack, FrameFormat format, Priority priority, uint16_t source, NPDU& npdu, bool status,
+                          SystemBroadcast broadcastType);
 
     // from transport layer
     void dataIndividualRequest(AckType ack, uint16_t destination, HopCountType hopType, Priority priority, TPDU& tpdu);
     void dataGroupRequest(AckType ack, uint16_t destination, HopCountType hopType, Priority priority, TPDU& tpdu);
-    void dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu);
-    void dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu);
+    void dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, SystemBroadcast broadcastType);
 
   private:
     void sendDataRequest(TPDU& tpdu, HopCountType hopType, AckType ack, uint16_t destination, Priority priority, AddressType addrType);
diff --git a/src/knx/property.cpp b/src/knx/property.cpp
index 3bdcb1d..a42989f 100644
--- a/src/knx/property.cpp
+++ b/src/knx/property.cpp
@@ -204,22 +204,18 @@ uint8_t Property::write(uint16_t position, uint16_t value)
     return write(position, 1, data);
 }
 
-uint8_t Property::command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength)
+void Property::command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength)
 {
     (void)data;
     (void)length;
     (void)resultData;
     resultLength = 0;
-
-    return 0xFF;
 }
 
-uint8_t Property::state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t &resultLength)
+void Property::state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t &resultLength)
 {
     (void)data;
     (void)length;
     (void)resultData;
     resultLength = 0;
-
-    return 0xFF;
 }
diff --git a/src/knx/property.h b/src/knx/property.h
index 0afe4b8..20bce5c 100644
--- a/src/knx/property.h
+++ b/src/knx/property.h
@@ -251,8 +251,8 @@ class Property : public SaveRestore
     uint8_t ElementSize() const;
     virtual uint8_t read(uint16_t start, uint8_t count, uint8_t* data) const = 0;
     virtual uint8_t write(uint16_t start, uint8_t count, const uint8_t* data) = 0;
-    virtual uint8_t command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength);
-    virtual uint8_t state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength);
+    virtual void command(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength);
+    virtual void state(uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength);
     uint8_t read(uint8_t& value) const;
     uint8_t read(uint16_t& value) const;
     uint8_t read(uint32_t& value) const;
diff --git a/src/knx/secure_application_layer.cpp b/src/knx/secure_application_layer.cpp
index 14e587c..9370958 100644
--- a/src/knx/secure_application_layer.cpp
+++ b/src/knx/secure_application_layer.cpp
@@ -55,7 +55,7 @@ void SecureApplicationLayer::dataGroupConfirm(AckType ack, HopCountType hopType,
     }
 }
 
-void SecureApplicationLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu)
+void SecureApplicationLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu, SystemBroadcast broadcastType)
 {
     if (apdu.type() == SecureService)
     {
@@ -64,31 +64,13 @@ void SecureApplicationLayer::dataBroadcastIndication(HopCountType hopType, Prior
     }
     else
     {
-        ApplicationLayer::dataBroadcastIndication(hopType, priority, source, apdu);
+        ApplicationLayer::dataBroadcastIndication(hopType, priority, source, apdu, broadcastType);
     }
 }
 
-void SecureApplicationLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status)
+void SecureApplicationLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status, SystemBroadcast broadcastType)
 {
-    ApplicationLayer::dataBroadcastConfirm(ack, hopType, priority, apdu, status);
-}
-
-void SecureApplicationLayer::dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu)
-{
-    if (apdu.type() == SecureService)
-    {
-        // Secure APDU is not allowed in Broadcast
-        println("Secure APDU in SystemBroadcast not allowed!");
-    }
-    else
-    {
-        ApplicationLayer::dataSystemBroadcastIndication(hopType, priority, source, apdu);
-    }
-}
-
-void SecureApplicationLayer::dataSystemBroadcastConfirm(HopCountType hopType, Priority priority, APDU& apdu, bool status)
-{
-    ApplicationLayer::dataSystemBroadcastConfirm(hopType, priority, apdu, status);
+    ApplicationLayer::dataBroadcastConfirm(ack, hopType, priority, apdu, status, broadcastType);
 }
 
 void SecureApplicationLayer::dataIndividualIndication(HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu)
@@ -198,7 +180,7 @@ void SecureApplicationLayer::dataBroadcastRequest(AckType ack, HopCountType hopT
 
 void SecureApplicationLayer::dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu)
 {
-    ApplicationLayer::dataSystemBroadcastRequest(AckDontCare, hopType, SystemPriority, apdu);
+    ApplicationLayer::dataSystemBroadcastRequest(ack, hopType, SystemPriority, apdu);
 }
 
 void SecureApplicationLayer::dataIndividualRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t destination, APDU& apdu)
diff --git a/src/knx/secure_application_layer.h b/src/knx/secure_application_layer.h
index 22e04f7..374189b 100644
--- a/src/knx/secure_application_layer.h
+++ b/src/knx/secure_application_layer.h
@@ -28,10 +28,8 @@ class SecureApplicationLayer :  public ApplicationLayer
     virtual void dataGroupIndication(HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu) override;
     virtual void dataGroupConfirm(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap,
                                   APDU& apdu, bool status) override;
-    virtual void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu) override;
-    virtual void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status) override;
-    virtual void dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu) override;
-    virtual void dataSystemBroadcastConfirm(HopCountType hopType, Priority priority, APDU& apdu, bool status) override;
+    virtual void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu, SystemBroadcast broadcastType) override;
+    virtual void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, bool status, SystemBroadcast broadcastType) override;
     virtual void dataIndividualIndication(HopCountType hopType, Priority priority, uint16_t source, APDU& apdu) override;
     virtual void dataIndividualConfirm(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu, bool status) override;
     virtual void connectIndication(uint16_t tsap) override;
diff --git a/src/knx/security_interface_object.cpp b/src/knx/security_interface_object.cpp
index a1641cd..5f414d4 100644
--- a/src/knx/security_interface_object.cpp
+++ b/src/knx/security_interface_object.cpp
@@ -31,28 +31,24 @@ SecurityInterfaceObject::SecurityInterfaceObject()
             }),
         new FunctionProperty<SecurityInterfaceObject>(this, PID_SECURITY_MODE, ReadLv3 | WriteLv0,
             // Command Callback of PID_SECURITY_MODE
-            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> uint8_t {
+            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> void {
                 // TODO
-                return 0;
             },
             // State Callback of PID_SECURITY_MODE
-            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> uint8_t {
+            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> void {
                 // TODO
-                return 0;
             }),
         new DataProperty( PID_P2P_KEY_TABLE, true, PDT_GENERIC_20, 1, ReadLv3 | WriteLv0, (uint16_t)0 ), // TODO: value
         new DataProperty( PID_GRP_KEY_TABLE, true, PDT_GENERIC_18, 1, ReadLv3 | WriteLv0, (uint16_t)0 ), // TODO: value
         new DataProperty( PID_SECURITY_INDIVIDUAL_ADDRESS_TABLE, true, PDT_GENERIC_08, 1, ReadLv3 | WriteLv0, (uint16_t)0 ), // TODO: value
         new FunctionProperty<SecurityInterfaceObject>(this, PID_SECURITY_FAILURES_LOG, ReadLv3 | WriteLv0,
             // Command Callback of PID_SECURITY_FAILURES_LOG
-            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> uint8_t {
+            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> void {
                 // TODO
-                return 0;
             },
             // State Callback of PID_SECURITY_FAILURES_LOG
-            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> uint8_t {
+            [](SecurityInterfaceObject* obj, uint8_t* data, uint8_t length, uint8_t* resultData, uint8_t& resultLength) -> void {
                 // TODO
-                return 0;
             }),
         new DataProperty( PID_TOOL_KEY, true, PDT_GENERIC_16, 1, ReadLv3 | WriteLv0, (uint16_t)0 ), // TODO: value (default is FDSK)
         new DataProperty( PID_SECURITY_REPORT, true, PDT_BITSET8, 1, ReadLv3 | WriteLv0, (uint16_t)0 ), // TODO: value
diff --git a/src/knx/transport_layer.cpp b/src/knx/transport_layer.cpp
index 91cafc9..aab3550 100644
--- a/src/knx/transport_layer.cpp
+++ b/src/knx/transport_layer.cpp
@@ -373,24 +373,14 @@ void TransportLayer::dataGroupConfirm(AckType ack, uint16_t source, uint16_t des
     _applicationLayer.dataGroupConfirm(ack, hopType, priority, destination, tpdu.apdu(), status);
 }
 
-void TransportLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu)
+void TransportLayer::dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu, SystemBroadcast broadcastType)
 {
-    _applicationLayer.dataBroadcastIndication(hopType, priority, source, tpdu.apdu());
+    _applicationLayer.dataBroadcastIndication(hopType, priority, source, tpdu.apdu(), broadcastType);
 }
 
-void TransportLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, bool status)
+void TransportLayer::dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, bool status, SystemBroadcast broadcastType)
 {
-    _applicationLayer.dataBroadcastConfirm(ack, hopType, priority, tpdu.apdu(), status);
-}
-
-void TransportLayer::dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu)
-{
-    _applicationLayer.dataSystemBroadcastIndication(hopType, priority, source, tpdu.apdu());
-}
-
-void TransportLayer::dataSystemBroadcastConfirm(AckType ack, HopCountType hopType, TPDU& tpdu, Priority priority, bool status)
-{
-    _applicationLayer.dataSystemBroadcastConfirm(hopType, priority, tpdu.apdu(), status);
+    _applicationLayer.dataBroadcastConfirm(ack, hopType, priority, tpdu.apdu(), status, broadcastType);
 }
 
 void TransportLayer::dataGroupRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu)
@@ -400,16 +390,10 @@ void TransportLayer::dataGroupRequest(AckType ack, HopCountType hopType, Priorit
     _networkLayer->dataGroupRequest(ack, groupAdress, hopType, priority, tpdu);
 }
 
-void TransportLayer::dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu)
+void TransportLayer::dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, SystemBroadcast broadcastType)
 {
     TPDU& tpdu = apdu.frame().tpdu();
-    _networkLayer->dataBroadcastRequest(ack, hopType, priority, tpdu);
-}
-
-void TransportLayer::dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu)
-{
-    TPDU& tpdu = apdu.frame().tpdu();
-    return _networkLayer->dataSystemBroadcastRequest(ack, hopType, priority, tpdu);
+    _networkLayer->dataBroadcastRequest(ack, hopType, priority, tpdu, broadcastType);
 }
 
 void TransportLayer::dataIndividualRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t destination, APDU& apdu)
diff --git a/src/knx/transport_layer.h b/src/knx/transport_layer.h
index f2d6c5e..00b11a9 100644
--- a/src/knx/transport_layer.h
+++ b/src/knx/transport_layer.h
@@ -24,10 +24,8 @@ public:
     void dataIndividualConfirm(AckType ack, uint16_t destination, HopCountType hopType, Priority priority, TPDU& tpdu, bool status);
     void dataGroupIndication(uint16_t destination, HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu);
     void dataGroupConfirm(AckType ack, uint16_t source, uint16_t destination, HopCountType hopType, Priority priority, TPDU& tpdu, bool status);
-    void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu);
-    void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, bool status);
-    void dataSystemBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu);
-    void dataSystemBroadcastConfirm(AckType ack, HopCountType hopType, TPDU& tpdu, Priority priority, bool status);
+    void dataBroadcastIndication(HopCountType hopType, Priority priority, uint16_t source, TPDU& tpdu, SystemBroadcast broadcastType);
+    void dataBroadcastConfirm(AckType ack, HopCountType hopType, Priority priority, TPDU& tpdu, bool status, SystemBroadcast broadcastType);
 #pragma endregion
     
 #pragma region from application layer
@@ -48,8 +46,7 @@ public:
      * @param ack Did we want a DataLinkLayer acknowledgement? See ::AckType.
      */
     void dataGroupRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t tsap, APDU& apdu);
-    void dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu);
-    void dataSystemBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu);
+    void dataBroadcastRequest(AckType ack, HopCountType hopType, Priority priority, APDU& apdu, SystemBroadcast broadcastType);
     void dataIndividualRequest(AckType ack, HopCountType hopType, Priority priority, uint16_t destination, APDU& apdu);
     
     void connectRequest(uint16_t destination, Priority priority);