Ethernet is a family of computer networking technologies commonly used in Local Area Networks (LANs) and Metropolitan Area Networks (MANs). It was originally developed at Xerox's Palo Alto Research Center (PARC) in the 1970s, where Robert Metcalfe and David Boggs pioneered the technology. Ethernet has since become the most widely installed network standard, evolving through numerous standards under the IEEE 802.3 committee.
History
- 1973: Robert Metcalfe writes a memo describing the "Alto Aloha Network" which later becomes Ethernet.
- 1976: Xerox files for a patent on Ethernet technology.
- 1980: The Digital Equipment Corporation (DEC), Intel, and Xerox (DIX) publish the first Ethernet standard, known as Ethernet Version 1.0.
- 1982: Ethernet Version 2.0 is released, which becomes the basis for the IEEE 802.3 standard.
- 1983: IEEE releases the first IEEE 802.3 standard, formalizing Ethernet into a globally recognized standard.
- 1990s onwards: Ethernet evolved to support higher speeds, moving from 10 Mbps to 100 Mbps (Fast Ethernet), 1 Gbps (Gigabit Ethernet), 10 Gbps, and beyond with standards like 40 Gbps, 100 Gbps, and 400 Gbps.
Technical Overview
Ethernet operates at the Data Link Layer of the OSI model, providing a means for computers to communicate within a LAN. Here are some key technical aspects:
- Frame Format: Ethernet frames consist of several fields including preamble, start frame delimiter, destination address, source address, length/type, data, and frame check sequence.
- CSMA/CD: Carrier Sense Multiple Access with Collision Detection was the initial method used to manage media access, though modern Ethernet often uses full-duplex communication, eliminating collisions.
- Cabling: Ethernet initially used coaxial cable but has since transitioned to twisted pair (e.g., Cat5, Cat6) and fiber optic cables for higher speed and longer distance communications.
- Speed: Ethernet standards have evolved to support speeds from 10 Mbps up to 400 Gbps with different physical layer specifications.
Standards and Variants
- 10BASE-T: Uses twisted pair wiring with a speed of 10 Mbps.
- 100BASE-TX: Known as Fast Ethernet, uses Category 5 cable with speeds up to 100 Mbps.
- 1000BASE-T: Gigabit Ethernet over twisted pair, utilizing Category 5 or higher cabling.
- 10GBASE-T: 10 Gigabit Ethernet over twisted pair, requiring Category 6 or higher.
- IEEE 802.3an: Standard for 10GBASE-T, supporting 10 Gbps over unshielded twisted pair cables.
Applications and Uses
Ethernet is used in a multitude of environments, from home networks to large data centers:
- Data Centers: High-speed Ethernet is critical for server interconnects and storage networks.
- Enterprise Networks: Provides backbone connectivity within corporate offices and campuses.
- Industrial Control: Ethernet has been adapted for industrial applications with protocols like PROFINET.
- Home Networks: Commonly used for connecting devices in homes, often through Wi-Fi which uses Ethernet as its backbone.
Future Developments
The evolution of Ethernet continues with research into higher speeds, lower latency, and energy efficiency. Standards like 802.3bs (200 Gbps and 400 Gbps) and future 800 Gbps Ethernet are in development to meet the growing bandwidth demands of data centers and cloud computing.
External Resources
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