Chapter 2-OSI Model

Chapter 2-OSI Model

1. Application Layer

   • Presentation Layer
     • Session Layer
       • Transport Layer
         • Network Layer
           • Data Link Layer
             • Physical Layer
               • The actual "wire". Data called bits
                 • DEVICES: ethernet cable, IR signals, hubs, extenders
             • Media Access Control
               • Gives the physical MAC addresses
             • Logical Link Control
               • ID's network layer protocols and encapsulating
             • DEVICES: Bridges, Switches. Data called frames
           • IP/network addressing. Data called packets
             • DEVICES: Routers
         • Chooses TCP or UDP and responsible for reliable delivery of UDP. Data called Segments
           • Syn, Syn/Ack, Ack
           • Flow Control
           • Windowing
           • Acknowledgements
       • Sets up the conversation between the two hosts. Responsible for keeping different applications' data separate. Data called PDU
     • Prepares data to be properly formatted for presentation. Also, compression and encryption. Data called PDU
   • Evaluates if resources are available and allocates if they are. Data called Protocol Data Unit (PDU)