diff --git a/src/knx/data_link_layer.h b/src/knx/data_link_layer.h
index 22920d9..abcd5d8 100644
--- a/src/knx/data_link_layer.h
+++ b/src/knx/data_link_layer.h
@@ -29,6 +29,7 @@ class DataLinkLayer
     virtual void loop() = 0;
     virtual void enabled(bool value) = 0;
     virtual bool enabled() const = 0;
+    virtual bool isOpenMedium() const = 0;
 
   protected:
     void frameRecieved(CemiFrame& frame);
diff --git a/src/knx/ip_data_link_layer.cpp b/src/knx/ip_data_link_layer.cpp
index 2409901..06f0b6d 100644
--- a/src/knx/ip_data_link_layer.cpp
+++ b/src/knx/ip_data_link_layer.cpp
@@ -99,6 +99,10 @@ bool IpDataLinkLayer::enabled() const
     return _enabled;
 }
 
+bool IpDataLinkLayer::isOpenMedium() const
+{
+    return false;
+}
 
 bool IpDataLinkLayer::sendBytes(uint8_t* bytes, uint16_t length)
 {
diff --git a/src/knx/ip_data_link_layer.h b/src/knx/ip_data_link_layer.h
index ee0cde8..46fee6d 100644
--- a/src/knx/ip_data_link_layer.h
+++ b/src/knx/ip_data_link_layer.h
@@ -17,6 +17,7 @@ class IpDataLinkLayer : public DataLinkLayer
     void loop();
     void enabled(bool value);
     bool enabled() const;
+    virtual bool isOpenMedium() const override;
 
   private:
     bool _enabled = false;
diff --git a/src/knx/network_layer.cpp b/src/knx/network_layer.cpp
index 8bd856a..a09c3b2 100644
--- a/src/knx/network_layer.cpp
+++ b/src/knx/network_layer.cpp
@@ -1,5 +1,6 @@
 #include "network_layer.h"
 #include "device_object.h"
+#include "data_link_layer.h"
 #include "tpdu.h"
 #include "cemi_frame.h"
 #include "bits.h"
@@ -108,8 +109,10 @@ void NetworkLayer::broadcastIndication(AckType ack, FrameFormat format, NPDU& np
 {
     HopCountType hopType = npdu.hopCount() == 7 ? UnlimitedRouting : NetworkLayerParameter;
 
+    DataLinkLayer& dlLayer = getEntity(npdu.frame().sourceInterface()).dataLinkLayer();
+
     // for closed media like TP1 and IP
-    if (isApciSystemBroadcast(npdu.tpdu().apdu()))
+    if (!dlLayer.isOpenMedium() && isApciSystemBroadcast(npdu.tpdu().apdu()))
     {
         npdu.frame().systemBroadcast(SysBroadcast);
         _transportLayer.dataSystemBroadcastIndication(hopType, priority, source, npdu.tpdu());
diff --git a/src/knx/network_layer_entity.cpp b/src/knx/network_layer_entity.cpp
index c812cc8..0fca763 100644
--- a/src/knx/network_layer_entity.cpp
+++ b/src/knx/network_layer_entity.cpp
@@ -14,6 +14,11 @@ void NetworkLayerEntity::dataLinkLayer(DataLinkLayer& layer)
     _dataLinkLayer = &layer;
 }
 
+DataLinkLayer& NetworkLayerEntity::dataLinkLayer()
+{
+    return *_dataLinkLayer;
+}
+
 void NetworkLayerEntity::dataIndication(AckType ack, AddressType addrType, uint16_t destination, FrameFormat format, NPDU& npdu, Priority priority, uint16_t source)
 {
     npdu.frame().sourceInterface(_entityIndex);
diff --git a/src/knx/network_layer_entity.h b/src/knx/network_layer_entity.h
index f111365..4071612 100644
--- a/src/knx/network_layer_entity.h
+++ b/src/knx/network_layer_entity.h
@@ -16,6 +16,7 @@ class NetworkLayerEntity
     NetworkLayerEntity(NetworkLayer &netLayer, uint8_t entityIndex);
 
     void dataLinkLayer(DataLinkLayer& layer);
+    DataLinkLayer& dataLinkLayer();
 
     // from data link layer
     void dataIndication(AckType ack, AddressType addType, uint16_t destination, FrameFormat format, NPDU& npdu,
diff --git a/src/knx/rf_data_link_layer.cpp b/src/knx/rf_data_link_layer.cpp
index d65be76..b8f4930 100644
--- a/src/knx/rf_data_link_layer.cpp
+++ b/src/knx/rf_data_link_layer.cpp
@@ -269,6 +269,11 @@ bool RfDataLinkLayer::enabled() const
     return _enabled;
 }
 
+bool RfDataLinkLayer::isOpenMedium() const
+{
+    return true;
+}
+
 void RfDataLinkLayer::fillRfFrame(CemiFrame& frame, uint8_t* data)
 {
     uint16_t crc;
diff --git a/src/knx/rf_data_link_layer.h b/src/knx/rf_data_link_layer.h
index f944317..71902e7 100644
--- a/src/knx/rf_data_link_layer.h
+++ b/src/knx/rf_data_link_layer.h
@@ -25,6 +25,7 @@ class RfDataLinkLayer : public DataLinkLayer
     void loop();
     void enabled(bool value);
     bool enabled() const;
+    virtual bool isOpenMedium() const override;
 
   private:
     bool _enabled = false;
diff --git a/src/knx/tpuart_data_link_layer.cpp b/src/knx/tpuart_data_link_layer.cpp
index 4b00aee..df6de5b 100644
--- a/src/knx/tpuart_data_link_layer.cpp
+++ b/src/knx/tpuart_data_link_layer.cpp
@@ -505,6 +505,11 @@ bool TpUartDataLinkLayer::enabled() const
     return _enabled;
 }
 
+bool TpUartDataLinkLayer::isOpenMedium() const
+{
+    return false;
+}
+
 bool TpUartDataLinkLayer::sendSingleFrameByte()
 {
     uint8_t cmd[2];
diff --git a/src/knx/tpuart_data_link_layer.h b/src/knx/tpuart_data_link_layer.h
index d49a783..3d06492 100644
--- a/src/knx/tpuart_data_link_layer.h
+++ b/src/knx/tpuart_data_link_layer.h
@@ -24,6 +24,7 @@ class TpUartDataLinkLayer : public DataLinkLayer
     void loop();
     void enabled(bool value);
     bool enabled() const;
+    virtual bool isOpenMedium() const override;
 
   private:
     bool _enabled = false;