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.

OSI and DOD networking models
Click here to view details about the Application layer. Click here to veiw information about the Presentation layer. Click here to view information about the Session layer. Click here to view information about the Transport layer. Click here to view information about the Network layer. Click here to view information about the Data Link layer. Click here to view information about the Physical layer.