CompTIA Network+ Protocol Data Units and OSI Layers Flashcards

Vocabulary flashcards focusing on Protocol Data Units (PDUs), Physical Layer transmission types, Data Link Layer frames, and MAC addresses from the CompTIA Network+ Guide to Networks transcript.

PDU (Protocol Data Unit)

The technical name for a group of bits as it moves from one layer to the next and from one LAN to the next, regardless of the layer.

L7PDU

The technical name for the Layer 7 (Application layer) Protocol Data Unit, which consists of the payload or data.

Layer 1 (Physical Layer)

The OSI model layer responsible for sending bits via a wired or wireless transmission, such as wavelengths in the air (Wi-Fi), voltage on a copper wire (Ethernet on twisted-pair cabling), or light (Ethernet on fiber-optic cabling).

NIC Firmware Layers

Refers to the Data Link Layer and Physical Layer, which are the only layers that must deal with the specific details of wired versus wireless transmissions.

Frame

The entire Data Link Layer message formed when the layer puts control information into a header and attaches control information to the end of a packet in a trailer.

Frame Header

The header attached to a Data Link Layer message that contains the hardware addresses (MAC addresses) of the source and destination NICs.

MAC (Media Access Control) Address

Also called a physical address, hardware address, or data link layer address; a short-range address embedded on every network adapter used only to find nodes on the local network.