Standard · Standards & Organisations
IEEE 802.3 (IEEE Standard for Ethernet)
The standard family defining Ethernet media access control and physical layers, at speeds from 1 Mb/s to 800 Gb/s over copper, optical fibre and automotive single-pair links.
Amendments are issued as lettered task force projects and folded into periodic base revisions.
- Also known as
- Ethernet
- Type
- Standard
- Domain
- Standards & Organisations, Networking & wireless
Notes
Automotive variants such as 100BASE-T1 and 1000BASE-T1 originated here and are profiled for cars by the OPEN Alliance.
Overview
IEEE 802.3 is the IEEE standard for Ethernet, defining the media access control (MAC) rules and the many physical layers that carry Ethernet frames over copper, optical fibre and backplanes. It is maintained by the IEEE 802.3 Working Group, which adds new speeds and media as lettered amendments and periodically folds them into a revised base standard. Chips for switches, network interface cards, servers, cars and factory equipment are built to its clauses.
How it works
The standard is organised as one common MAC, which frames data and once handled shared-medium access using CSMA/CD, plus speed-specific media-independent interfaces and physical layer devices (PHYs) for each medium. The current base edition, IEEE 802.3-2022, covers speeds from 1 Mb/s to 400 Gb/s over coaxial cable, twisted pair, optical fibre and electrical backplanes, together with power delivery over selected twisted-pair PHYs and PHYs for access and metropolitan networks.
New work is done by task forces, each producing an amendment with a two-letter suffix. Examples include 802.3ab for 1000BASE-T over twisted pair, 802.3bt for higher-power Power over Ethernet, 802.3bw and 802.3bp for automotive single-pair links, 802.3cg for 10 Mb/s single-pair Ethernet, and 802.3df, approved in February 2024, for 400 Gb/s and 800 Gb/s operation. When enough amendments accumulate, they are merged into a new revision of the base standard, as happened with 802.3-2022.
Each PHY, such as 10GBASE-KR for 10 Gb/s backplane links, has its own clauses for coding and electrical or optical limits, and backplane PHYs add a start-up training protocol. Work under way at the time of writing includes 1.6 Tb/s Ethernet and further automotive PHYs.
Examples
- A data centre switch ASIC with 800 Gb/s Ethernet ports based on the 802.3df amendment.
- A server network interface card supporting several 802.3 PHY types over copper cables and optical modules.
- A 10GBASE-KR backplane link in network equipment, which uses the standard's start-up training to tune its equalisers.
- An automotive gateway chip with 100BASE-T1 and 1000BASE-T1 single-pair Ethernet ports for in-vehicle networks.
- A wireless access point powered over its Ethernet cable using 802.3bt Power over Ethernet.
Why it matters
Ethernet MAC, PCS and SerDes designers implement its clauses directly, switch and NIC architects choose which PHY types to support, and verification and validation engineers test against its electrical and protocol requirements. Because data centres, enterprise networks and increasingly vehicles all run on Ethernet, compliance and interoperability with the relevant 802.3 clauses are usually a basic requirement for networking silicon.
Related terms
Part of the Standards & Organisations glossary, with every term in the topic and the lifecycles, tools and standards that use them.
Where it appears on the Hub
Used on 11 pages of the Hub. In each group, the pages that mention it most come first.
Lifecycle stages and gates
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