I've gotten confused when reading about encapsulation and the OSI and TCP/IP models. I first read about message formatting and encapsulation and the diagram I read showed:
Destination | Source
and these are the frame addressing
and this is followed by the encapsulated message which involves:
Start message indicator| Receiver | Sender | Encapsulated bits
and then ends with the CRC.
I understand that but then I read about OSI and TCP/IP model. But where does all of what I said above (message formatting encapsulation) come into? I know there are different layers but these are different to the format I just mentioned, they apply each header as they pass the PDU down the stack. I'm just confused at when the format I explained above is used.