8023an

IEEE 802.3an, commonly referred to as 802.3an or 802.3an-2006, is an amendment to the IEEE 802.3 Ethernet standard that defines 10 Gigabit Ethernet over copper twisted-pair cabling. It specifies the physical layer and associated technologies required to transmit data at 10 gigabits per second over four pairs of copper, using standard RJ-45 connectors at distances up to about 100 meters on category 6a or better cabling. The amendment was introduced to enable high-speed, cost-effective backbone and inter-switch connections in enterprise networks.

Technically, 802.3an enables full-duplex operation over copper and relies on advanced signaling, error correction, and channel equalization to manage signal integrity and crosstalk on multi-pair copper cabling. It uses existing Ethernet framing and MAC-layer structures, with a dedicated physical coding sublayer and physical medium dependent sublayer for the copper interface. Because of its reliance on four-pair cabling and high-speed signaling, devices implementing 802.3an require 10GBASE-T capable network interface cards and switches, and typically support auto-negotiation with compatible peers.

In deployment, 802.3an found rapid adoption in data centers and enterprise networks as a practical means to extend high bandwidth between switches and servers without replacing fiber infrastructure. The standard is part of the broader IEEE 802.3 family and has influenced subsequent copper-based Ethernet developments. While it remains foundational, many networks now parallel or upgrade to newer standards and higher-speed copper or fiber options as requirements evolve.