IEEE 802.3 is the official Ethernet standard maintained by the Institute of Electrical and Electronics Engineers (IEEE). It defines the Physical Layer and Data Link Layer specifications for wired Ethernet networks, including signaling methods, frame formats, cabling requirements, speed classifications, and media types.
What IEEE 802.3 Defines:
- Physical media (copper, fiber, coax)
- Speed standards (10 Mbps → 100 Gbps+)
- Encoding schemes (Manchester, 4B/5B, 8B/10B, PAM‑5, PAM‑16)
- MAC addressing and CSMA/CD behavior
- Frame structure (preamble, header, payload, FCS)
- Auto‑negotiation and link training
Why It Matters:
IEEE 802.3 ensures interoperability between vendors and guarantees that Ethernet devices follow the same electrical and logical rules. Every Ethernet cable, NIC, switch, and transceiver is built to comply with this standard.