Ethernet and IEEE802.3 for legacy Ethernet:

Ethernet is a baseband LAN standard invented by Xerox. It uses Carrier Supervisory Multiple Access Protocol with Conflict Detection (CSMA/CD) at a rate of 10 Mbps, and the transmission medium is coaxial cable. Ethernet was developed in the 1970s to address sporadic and occasional congestion in networks, and the IEEE 802.3 standard was developed in 1980 based on the original Ethernet technology. The term Ethernet is now used generically to refer to all local area networks that utilize the CSMA/CD protocol. Ethernet version 2.0 was jointly developed by Digital Equipment Corporation, Intel Corporation and Xerox Corporation, and it is compatible with IEEE802.3.

Ethernet and IEEE802.3 are usually implemented by an interface card (NIC) or circuitry on the main circuit board. The Ethernet cable protocol specifies a transceiver to connect the cable to the physical devices of the network. The transceiver performs most of the functions of the physical layer, including conflict detection and transceiver cables to connect the transceiver to the workstation.

IEEE802.3 provides several cable specifications, including 10Base5, which is the closest to Ethernet. In this specification, the connecting cable is called an attachment unit interface (AUI), and the network-connecting device is called a media access unit (MAU) and is no longer a transceiver. In broadcast-based Ethernet, all workstations can receive an information frame sent to the network. Each workstation verifies that the frame is not addressed to it, and once it has confirmed that it is addressed to it, it sends it to a higher protocol layer.

In Ethernet with CSMA/CD transport media access, any CSMA/CDLAN workstation can access the network at any given moment. Before sending data, the workstation listens for network congestion and can only send data if it detects that the network is idle.

In contention-based Ethernet, either workstation can send data as long as the network is free. A conflict occurs when two workstations find the network free and send data at the same time. At this point, both transmission operations are corrupted, and the workstations must retransmit after a certain period of time, when the retransmission is determined by a delay algorithm. Although there are many similarities between Ethernet and the IEEE802.3 standard, there are some differences. The services provided by Ethernet correspond to layers 1 and 2 of the OSI reference model, while the services provided by IEEE802.3 correspond to the channel access portion (i.e., a portion of layer 2) of layers 1 and 2 of the OSI reference model.IEEE802.3 does not define a logical link control protocol, but does define several different physical layers, while Ethernet defines only one.

Each of the IEEE802.3 physical layer protocols can be characterized in three ways: the speed of the LAN, the method of signaling, and the type of physical media.