diff --git a/include/etl/fsm.h b/include/etl/fsm.h
index 8ba4b972..84bb34c7 100644
--- a/include/etl/fsm.h
+++ b/include/etl/fsm.h
@@ -238,7 +238,7 @@ namespace etl
     /// Starts the FSM.
     /// Can only be called once.
     /// Subsequent calls will do nothing.
-    ///\param call_on_enter_state If will call on_enter_state() for the first state. Default = true.
+    ///\param call_on_enter_state If true will call on_enter_state() for the first state. Default = true.
     //*******************************************
     void start(bool call_on_enter_state = true)
     {
@@ -273,6 +273,17 @@ namespace etl
       receive(nmr, message);
     }
 
+    //*******************************************
+    /// Top level message handler for the FSM.
+    //*******************************************
+    void receive(imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& message)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, message);
+      }
+    }
+
     //*******************************************
     /// Top level message handler for the FSM.
     //*******************************************
@@ -360,6 +371,12 @@ namespace etl
       p_state = nullptr;
     }
 
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
+
   private:
 
     etl::ifsm_state*    p_state;          ///< A pointer to the current state.
@@ -390,7 +407,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -455,7 +472,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -519,7 +536,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -582,7 +599,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -643,7 +660,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -703,7 +720,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -762,7 +779,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -820,7 +837,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -876,7 +893,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -931,7 +948,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -985,7 +1002,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1038,7 +1055,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1089,7 +1106,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1139,7 +1156,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1188,7 +1205,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1236,7 +1253,7 @@ namespace etl
     }
 
   protected:
-      
+
     ~fsm_state()
     {
     }
@@ -1280,9 +1297,9 @@ namespace etl
       : ifsm_state(STATE_ID)
     {
     }
-  
+
   protected:
-      
+
     ~fsm_state()
     {
     }
diff --git a/include/etl/fsm_generator.h b/include/etl/fsm_generator.h
index 176fa60d..4dbe9715 100644
--- a/include/etl/fsm_generator.h
+++ b/include/etl/fsm_generator.h
@@ -285,6 +285,17 @@ namespace etl
       receive(nmr, message);
     }
 
+    //*******************************************
+    /// Top level message handler for the FSM.
+    //*******************************************
+    void receive(imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& message)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, message);
+      }
+    }
+
     //*******************************************
     /// Top level message handler for the FSM.
     //*******************************************
@@ -372,6 +383,12 @@ namespace etl
       p_state = nullptr;
     }
 
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
+
   private:
 
     etl::ifsm_state*    p_state;          ///< A pointer to the current state.
diff --git a/include/etl/message_bus.h b/include/etl/message_bus.h
index 90d9b01f..7e19ccd6 100644
--- a/include/etl/message_bus.h
+++ b/include/etl/message_bus.h
@@ -102,21 +102,12 @@ namespace etl
 
         if (ok)
         {
-          if (router.is_bus())
-          {
-            // Message busses get added to the end.
-            router_list.push_back(&router);
-          }
-          else
-          {
-            // Routers get added in id order.
-            router_list_t::iterator irouter = std::upper_bound(router_list.begin(),
-                                                               router_list.end(),
-                                                               router.get_message_router_id(),
-                                                               compare_router_id());
+          router_list_t::iterator irouter = std::upper_bound(router_list.begin(),
+                                                             router_list.end(),
+                                                             router.get_message_router_id(),
+                                                             compare_router_id());
 
-            router_list.insert(irouter, &router);
-          }
+          router_list.insert(irouter, &router);
         }
       }
 
@@ -203,17 +194,9 @@ namespace etl
           {
             etl::imessage_router& router = **irouter;
 
-            if (router.is_bus())
+            if (router.accepts(message.message_id))
             {
-              // The router is actually a bus.
-              etl::imessage_bus& bus = static_cast<etl::imessage_bus&>(router);
-
-              // So pass it on.
-              bus.receive(source, destination_router_id, message);
-            }
-            else if (router.accepts(message.message_id))
-            {
-              router.receive(source, message);
+              router.receive(source, destination_router_id, message);
             }
 
             ++irouter;
@@ -254,11 +237,8 @@ namespace etl
 
           while (irouter != router_list.end())
           {
-            // The router is actually a bus.
-            etl::imessage_bus& bus = static_cast<etl::imessage_bus&>(**irouter);
-
             // So pass it on.
-            bus.receive(source, destination_router_id, message);
+            (*irouter)->receive(source, destination_router_id, message);
 
             ++irouter;
           }
@@ -291,6 +271,12 @@ namespace etl
       return router_list.clear();
     }
 
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
+
   protected:
 
     //*******************************************
diff --git a/include/etl/message_router.h b/include/etl/message_router.h
index 884910b7..26a68b45 100644
--- a/include/etl/message_router.h
+++ b/include/etl/message_router.h
@@ -102,7 +102,9 @@ namespace etl
     virtual ~imessage_router() {}
     virtual void receive(const etl::imessage& message) = 0;
     virtual void receive(imessage_router& source, const etl::imessage& message) = 0;
+    virtual void receive(imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& message) = 0;
     virtual bool accepts(etl::message_id_t id) const = 0;
+    virtual bool is_null_router() const = 0;
 
     //********************************************
     bool accepts(const etl::imessage& msg) const
@@ -116,18 +118,6 @@ namespace etl
       return message_router_id;
     }
 
-    //********************************************
-    bool is_null_router() const
-    {
-      return (message_router_id == NULL_MESSAGE_ROUTER);
-    }
-
-    //********************************************
-    bool is_bus() const
-    {
-      return (message_router_id == MESSAGE_BUS);
-    }
-
     //********************************************
     void set_successor(imessage_router& successor_)
     {
@@ -203,12 +193,23 @@ namespace etl
     {
     }
 
+    //********************************************
+    void receive(imessage_router&, etl::message_router_id_t, const etl::imessage&)
+    {
+    }
+
     //********************************************
     bool accepts(etl::message_id_t) const
     {
       return false;
     }
 
+    //********************************************
+    bool is_null_router() const
+    {
+      return true;
+    }
+
     //********************************************
     static null_message_router& instance()
     {
@@ -369,6 +370,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -421,6 +431,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -554,6 +570,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -605,6 +630,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -736,6 +767,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -786,6 +826,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -915,6 +961,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -964,6 +1019,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1090,6 +1151,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1138,6 +1208,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1262,6 +1338,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1309,6 +1394,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1431,6 +1522,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1477,6 +1577,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1597,6 +1703,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1642,6 +1757,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1759,6 +1880,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1803,6 +1933,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -1918,6 +2054,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -1960,6 +2105,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2073,6 +2224,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2114,6 +2274,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2225,6 +2391,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2265,6 +2440,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2373,6 +2554,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2412,6 +2602,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2518,6 +2714,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2556,6 +2761,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2660,6 +2871,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2697,6 +2917,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 
   //***************************************************************************
@@ -2799,6 +3025,15 @@ namespace etl
       receive(etl::null_message_router::instance(), msg);
     }
 
+    //**********************************************
+    void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)
+    {
+      if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))
+      {
+        receive(source, msg);
+      }
+    }
+
     //**********************************************
     void receive(etl::imessage_router& source, const etl::imessage& msg)
     {
@@ -2835,6 +3070,12 @@ namespace etl
           return false; break;
       }
     }
+
+    //********************************************
+    bool is_null_router() const
+    {
+      return false;
+    }
   };
 }
 
diff --git a/include/etl/message_router_generator.h b/include/etl/message_router_generator.h
index 44c6a44b..8049b5e1 100644
--- a/include/etl/message_router_generator.h
+++ b/include/etl/message_router_generator.h
@@ -114,7 +114,9 @@ namespace etl
     virtual ~imessage_router() {}
     virtual void receive(const etl::imessage& message) = 0;
     virtual void receive(imessage_router& source, const etl::imessage& message) = 0;
+    virtual void receive(imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& message) = 0;
     virtual bool accepts(etl::message_id_t id) const = 0;
+    virtual bool is_null_router() const = 0;
 
     //********************************************
     bool accepts(const etl::imessage& msg) const
@@ -128,18 +130,6 @@ namespace etl
       return message_router_id;
     }
 
-    //********************************************
-    bool is_null_router() const
-    {
-      return (message_router_id == NULL_MESSAGE_ROUTER);
-    }
-
-    //********************************************
-    bool is_bus() const
-    {
-      return (message_router_id == MESSAGE_BUS);
-    }
-
     //********************************************
     void set_successor(imessage_router& successor_)
     {
@@ -215,12 +205,23 @@ namespace etl
     {
     }
 
+    //********************************************
+    void receive(imessage_router&, etl::message_router_id_t, const etl::imessage&)
+    {
+    }
+
     //********************************************
     bool accepts(etl::message_id_t) const
     {
       return false;
     }
 
+    //********************************************
+    bool is_null_router() const
+    {
+      return true;
+    }
+
     //********************************************
     static null_message_router& instance()
     {
@@ -376,6 +377,15 @@ namespace etl
       cog.outl("  }")
       cog.outl("")
       cog.outl("  //**********************************************")
+      cog.outl("  void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)")
+      cog.outl("  {")
+      cog.outl("    if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))")
+      cog.outl("    {")
+      cog.outl("      receive(source, msg);")
+      cog.outl("    }")
+      cog.outl("  }")
+      cog.outl("")
+      cog.outl("  //**********************************************")
       cog.outl("  void receive(etl::imessage_router& source, const etl::imessage& msg)")
       cog.outl("  {")
       cog.outl("    const etl::message_id_t id = msg.message_id;")
@@ -419,6 +429,12 @@ namespace etl
       cog.outl("        return false; break;")
       cog.outl("    }")
       cog.outl("  }")
+      cog.outl("")
+      cog.outl("  //********************************************")
+      cog.outl("  bool is_null_router() const")
+      cog.outl("  {")
+      cog.outl("    return false;")
+      cog.outl("  }")
       cog.outl("};")
 
       ####################################
@@ -561,6 +577,15 @@ namespace etl
           cog.outl("  }")
           cog.outl("")
           cog.outl("  //**********************************************")
+          cog.outl("  void receive(etl::imessage_router& source, etl::message_router_id_t destination_router_id, const etl::imessage& msg)")
+          cog.outl("  {")
+          cog.outl("    if ((destination_router_id == get_message_router_id()) || (destination_router_id == imessage_router::ALL_MESSAGE_ROUTERS))")
+          cog.outl("    {")
+          cog.outl("      receive(source, msg);")
+          cog.outl("    }")
+          cog.outl("  }")
+          cog.outl("")
+          cog.outl("  //**********************************************")
           cog.outl("  void receive(etl::imessage_router& source, const etl::imessage& msg)")
           cog.outl("  {")
           cog.outl("    const size_t id = msg.message_id;")
@@ -605,6 +630,12 @@ namespace etl
           cog.outl("        return false; break;")
           cog.outl("    }")
           cog.outl("  }")
+          cog.outl("")
+          cog.outl("  //********************************************")
+          cog.outl("  bool is_null_router() const")
+          cog.outl("  {")
+          cog.outl("    return false;")
+          cog.outl("  }")
           cog.outl("};")
   ]]]*/
   /*[[[end]]]*/
diff --git a/include/etl/message_timer.h b/include/etl/message_timer.h
index 1da2f363..4e554121 100644
--- a/include/etl/message_timer.h
+++ b/include/etl/message_timer.h
@@ -63,7 +63,7 @@ SOFTWARE.
   #if !defined(ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS) || !defined(ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS)
     #error ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS and/or ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS not defined
   #endif
-  
+
   #define ETL_DISABLE_TIMER_UPDATES (ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS)
   #define ETL_ENABLE_TIMER_UPDATES  (ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS)
   #define ETL_TIMER_UPDATES_ENABLED true
@@ -95,24 +95,17 @@ namespace etl
                        etl::imessage_router&    irouter_,
                        uint32_t                 period_,
                        bool                     repeating_,
-                       etl::message_router_id_t destination_router_id_)
+                       etl::message_router_id_t destination_router_id_ = etl::imessage_bus::ALL_MESSAGE_ROUTERS)
       : p_message(&message_),
         p_router(&irouter_),
         period(period_),
         delta(etl::timer::state::INACTIVE),
+        destination_router_id(destination_router_id_),
         id(id_),
         previous(etl::timer::id::NO_TIMER),
         next(etl::timer::id::NO_TIMER),
         repeating(repeating_)
     {
-      if (irouter_.is_bus())
-      {
-        destination_router_id = destination_router_id_;
-      }
-      else
-      {
-        destination_router_id = etl::imessage_bus::ALL_MESSAGE_ROUTERS;
-      }
     }
 
     //*******************************************
@@ -471,17 +464,8 @@ namespace etl
 
               if (timer.p_router != nullptr)
               {
-                if (timer.p_router->is_bus())
-                {
-                  // Send to a message bus.
-                  etl::imessage_bus& bus = static_cast<etl::imessage_bus&>(*(timer.p_router));
-                  bus.receive(timer.destination_router_id, *(timer.p_message));
-                }
-                else
-                {
-                  // Send to a router.
-                  timer.p_router->receive(*(timer.p_message));
-                }
+                static etl::null_message_router nmr;
+                timer.p_router->receive(nmr, timer.destination_router_id, *(timer.p_message));
               }
 
               has_active = !active_list.empty();
@@ -576,7 +560,7 @@ namespace etl
         timer_array[id_].period = period_;
         return true;
       }
-      
+
       return false;
     }
 
@@ -627,7 +611,7 @@ namespace etl
     private_message_timer::list active_list;
 
     volatile bool enabled;
-    
+
 #if defined(ETL_MESSAGE_TIMER_USE_ATOMIC_LOCK)
     volatile etl::timer_semaphore_t process_semaphore;
 #endif
diff --git a/include/etl/version.h b/include/etl/version.h
index 970ebd80..269c6153 100644
--- a/include/etl/version.h
+++ b/include/etl/version.h
@@ -38,7 +38,7 @@ SOFTWARE.
 ///\ingroup utilities
 
 #define ETL_VERSION_MAJOR 14
-#define ETL_VERSION_MINOR 25
+#define ETL_VERSION_MINOR 26
 #define ETL_VERSION_PATCH  0
 
 #define ETL_VERSION       ETL_STRINGIFY(ETL_VERSION_MAJOR) ETL_STRINGIFY(ETL_VERSION_MINOR) ETL_STRINGIFY(ETL_VERSION_PATCH)
diff --git a/support/Release notes.txt b/support/Release notes.txt
index 0d23f4a8..5ac382ca 100644
--- a/support/Release notes.txt	
+++ b/support/Release notes.txt	
@@ -1,3 +1,9 @@
+===============================================================================
+14.26.0
+Simplified message framework internal code.
+Additional receive() virtual function overload taking destination id.
+Removed is_bus() member function.
+
 ===============================================================================
 14.25.0
 Added variadic template versions of etl::largest, etl::largest_type,
diff --git a/test/test_message_bus.cpp b/test/test_message_bus.cpp
index 483a914e..db4dfba6 100644
--- a/test/test_message_bus.cpp
+++ b/test/test_message_bus.cpp
@@ -255,10 +255,10 @@ namespace
       RouterA router3(ROUTER3);
       RouterA router4(ROUTER4);
 
-      bus1.subscribe(router1);
-      bus1.subscribe(router2);
       bus1.subscribe(bus2);
+      bus1.subscribe(router1);
       bus1.subscribe(bus3);
+      bus1.subscribe(router2);
 
       bus2.subscribe(router3);
       bus3.subscribe(router4);