Ethernet The Most Popular LAN Technology Carries perhaps

Ethernet • The Most Popular LAN Technology – Carries perhaps 80% of all LAN traffic • Created at the Xerox Palo Alto Research Center (PARC) • Initially standardized by Digital Equipment Corporation, Intel, and Xerox – Ethernet Version 2 (Ethernet II) was the final standard of this partnership – Still used on some LANs

LAN Standards • Now, most LAN Standards are Developed by the IEEE – Institute for Electrical and Electronics Engineers – Not just Ethernet LAN standards

LAN Standards • Now, most LAN Standards are Developed by the IEEE – Developed through the IEEE’s 802 LAN MAN Standards Committee • MAN is a metropolitan area network (for a city and its suburbs) – IEEE LAN standards are submitted to ISO for ratification as OSI standards

LAN Standards • 802 Committee has Working Groups – Working groups develop individual standards – Submit to whole 802 committee – 802. 1 develops priority standards and other general standards – 802. 3 has taken over the development of new Ethernet standards – 802. 5 develops Token-Ring Network standards – 802. 11 develops wireless LAN standards

LANs are Subnet Standards • Only Physical and Data Link Layer standards • Of course, clients and servers must be compatible at other layers as well Application Transport Internet LAN Subnet (NIC)

LANs are Subnet Standards • Implemented by the NICs – NICs on the two machines must talk to one another • Hubs and Switches Merely Relay Transmissions – Hubs implement Physical layer only (no Data Link layer needed) – Switches implement the Physical and Data Link layers • Wiring Implements Physical Layer