Open Systems Interconnect (OSI) Model
Networking Layers, PDUs, and Protocols By Model
Instructions: Click on a layer name in the OSI column below to view more information about the layer. Pay close attention to the numerical order of the layers, the data format of the PDUs at each layer, and which protocols operate at which layer. Also, you'll need to know the names and stacking order of the two sub-layers of the Data Link layer.