+-----------------------------------+
                         | Department of Defense (DOD) Model |
                         +-----------------------------------+



           -------+------ Applicazione (Programma che gira nel sistema operativo)
                  |
                  |
+-----------------+-------------------+
|    Utility and Services Layer       |\
|- - - - - - - - - - - - - - - - - - -| >--- Application Layer
|   Network Application APIs Layer    |/
+-------------------------------------+
|         Transport Layer             |
+-------------------------------------+
|         Internet  Layer             |
+-------------------------------------+ 
|      Network Interface Layer        |
+-----------------+-------------------+
                  |
                  |
           -------+------ Livello fisico (Cavo di Rete)