Module Ethernet Technology Module Ethernet Technology

Ethernet Technology Rev Page 2 May 1996 u 1973 Development begins u 1976 First paper on Ethernet published u 1977 Ethernet is patented u 1979 DEC, INTEL, and XEROX collaborate on Ethernet Version 1. u 1980 Ethernet V.1 is published u 1980 Xerox ships first Ethernet u 1982 Ethernet version 2 is published u 1983 IEEE approves standard u 1985 Ethernet is produces by more than 200 vendors u 1985 Installed base exceeds Units u Fast Ethernet / 100 Mbps/ Switching Ethernet - the History

Ethernet Technology Rev Page 3 May 1996 Protocols Layer Network Logical Link Media Access Control Physical Link Metro Area Network Logical Link Control Token Passing Bus Media Access Token Passing Ring CSMA/CD 802 Internetworking Access Control Access Control Access Control 802 Network Architecture Management 10BASE-210BASE-510BASE-T10BASE-F IEEE standards

Ethernet Technology Rev Page 4 May 1996 u CSMA/CD Carrier Sense Carrier Sense Listen before trying to transmit - is the cable free? Listen before trying to transmit - is the cable free? Multiple Access Multiple Access Many Stations are allowed to use the same media Collision Detect Collision Detect Be aware of signal collisions - back off when detected 50 ohm Terminator 50 ohm Terminator Computer earth Signal Ethernet Access Method Shared media ( bus ) Collision

Ethernet Technology Rev Page 5 May 1996 Ethernet Frames Preample (62 bits) Sync 11 (2 bits) DA (6 bytes) Type (2 bytes) Data.....(padding) SA (6 bytes) FCS (4 bytes) ( bytes) Ethernet V.II MAC addresses Preample (56 bits) SFD (8 bits) DA (6 bytes) Length (2 bytes) Data.....(padding) SA (6 bytes) FCS (4 bytes) ( bytes) IEEE MAC addresses

Ethernet Technology Rev Page 6 May 1996 u Physical Signalling u Collision Detect u SQE Test u Jabber Function TX Wires RX Wires Collision Power Ethernet Transceiver Drop cable to station (AUI Interface) LAN media Transceiver

Ethernet Technology Rev Page 7 May 1996 u Max. 500 m. Cable Segments u Max. 100 Stations per Cable Segment u 2.5 m. between Transceivers u 50 Ohm terminator at each end 10BASE-5 Yellow Cable 50 ohm Terminator 50 ohm Terminator Computer earth (IEEE802.3 media) 2.5 m. Drop cable Transceiver AUI interface

Ethernet Technology Rev Page 8 May 1996 u Max. 185 m. Cable Segments u Max. 30 Stations per Cable Segment u Min. 0.5 m. Distance between Stations u BNC Connectors used to attach stations u 50 Ohm terminator at each end BNC T Connector Build-in transceiver 50 ohm Terminator 10BASE-2 Cheapernet Cable External transceiver Drop cable AUI interface

Ethernet Technology Rev Page 9 May 1996 u Requires a Cabling Hub u Max. 100 m. from Station to Hub 10BASE-T UTP Cable Star topology Cabling Hub (repeater) 100 m. Cable segments

Ethernet Technology Rev Page 10 May 1996 u Noise Immune u No Ground Loops u Long Distance (up to 2Km.) u Stations connect to a Central Hub u Max. Two Stations per Cable Segment u Typically used for Inter-Hub Connectivity 10BASE-F Fiber Optic Cable

Ethernet Technology Rev Page 11 May 1996 u Increased Flexibility u Improved Availability u Inherent Management Capabilities Intelligent structured wiring systems Cabling HubPatch panel Cabling conducts RJ-45 outlets Network Management - control - monitoring Port status: - active - not active - partitioned

Ethernet Technology Rev Page 12 May BASE-T&F Design Rules Link segments BASE-F Max. 500 m. 10BASE-T Max. 100 m BASE-F Max m. 10BASE-T Max. 100 m.

Ethernet Technology Rev Page 13 May 1996 u Bridges Receive and Buffer the Frames u Each Side of a Bridge is a Separate Collision Domain u Bridges Decide to Discard or Forward Packets u Bridges allow for a more Effective Utilization of the Overall Bandwidth Collision Domain Collision Domain Ethernet Transparent Bridges Bridge Dedicated 10 Mbps Dedicated 10 Mbps

Ethernet Technology Rev Page 14 May 1996 Fast Ethernet 100 Mbps: î 100BASE-T or î 100VG-AnyLAN

Ethernet Technology Rev Page 15 May 1996 Switched Ethernet Ethernet Switch Shared 10Mbps segmentDedicated 10Mbps segments 100BASE-T Full duplex 10Mbps Existing cabling and adapters Replaces the old Hub

Ethernet Technology Rev Page 16 May 1996