Overview Ethernet is defined by the IEEE 802.2 and 802.3 standards. The 802.2 standard defines the logical link layer, the upper sub-layer of the Data Link layer. 802.3 defines the Media Access Control (MAC) sub-layer of the data link layer which defines framing, encoding, and signaling methods for the underlying hardware which will be transmitting and receiving streams of bits to and from the media. Ethernet Frame Structure Types of Ethernet