Ethernet Technologies and Gigabit Ethernet Professor John Gorgone Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 1 Topics • Origins of Ethernet • Ethernet 10 MBS • Fast Ethernet 100 MBS • Gigabit Ethernet 1000 MBS • Comparison Tables • ATM VS Gigabit Ethernet •Ethernet8SummaryCopyright 1998, John T. Gorgone, All Rights Reserved 2 Origins • Original Idea sprang from Abramson’s Aloha Network--University of Hawaii • CSMA/CD Thesis Developed by Robert Metcalfe----(1972) • Experimental Ethernet developed at Xerox Palo Alto Research Center---1973 • Xerox’s Alto Computers -- First Ethernet Ethernet8systemsCopyright 1998, John T. Gorgone, All Rights Reserved 3 DIX STANDARD • Digital, Intel, and Xerox combined to developed the DIX Ethernet Standard • 1980 -- DIX Standard presented to the IEEE • 1980 -- IEEE creates the 802 committee to create acceptable Ethernet Standard Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 4 Ethernet Grows • Open Standard allows Hardware and Software Developers to create numerous products based on Ethernet • Large number of Vendors keeps Prices low and Quality High • Compatibility Problems Rare Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 5 What is Ethernet? • A standard for LANs • The standard covers two layers of the ISO model – Physical layer – Data link layer Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 6 What is Ethernet? • Transmission speed of 10 Mbps • Originally, only baseband • In 1986, broadband was introduced • Half duplex and full duplex technology • Bus topology Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 7 Components of Ethernet • Physical Medium • Medium Access Control • Ethernet Frame Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 8 CableCable DesignationsDesignations 10 BASE T SPEED TRANSMISSION MAX TYPE LENGTH Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 9 Physical Medium • Thick Ethernet (coaxial) 10BASE5 • Thin Ethernet (coaxial) 10BASE2 • UTP (twisted pair) 10BASET – CATEGORY 5 --------------- 100 MBS • Fiber 10BASEF • Broadband (coaxial) 10BROAD36 Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 10 Ethernet Physical Medium 10Base5 - Thick Coaxial • Original Ethernet • Coaxial cable, 0.25 inch in diameter • Segments length up to 500 m Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 11 Ethernet Physical Medium 10Base2 - Thin Coaxial or CheaperNet • Fairly popular; still used in many environment • Coaxial cable, 0.2 inch in diameter • Segments length up to 185 m Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 12 Ethernet Physical Medium 10BaseT - Twisted Pair • Commonly used for telephones; very economical • Twisted pair, unshielded • Segments length up to 150 m Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 13 Ethernet Physical Medium 10BaseF - Fiber Optics • Excellent for electrical isolation • Fiber optics cable • Segments length up to 2,000 m Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 14 Ethernet Physical Medium 10Broad36 - Coaxial Broadband • Covers greater distances at greater cost • Coaxial cable, broadband • Segments length to 3,600 m Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 15 MEDIUM ACCESS • Access to shared Channel achieved by CSMA/CD • CARRIER SENSE • MULTIPLE ACCESS • COLLISION DETECTION Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 16 COLLISIONS • Collisions are a Normal Occurance • Collision Signal is sent to all Nodes • Two Conflicting Stations Wait A Random Delay Period and then Retransmit • Retransmits Frame up to 16 Times before Discarding Frame Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 17 COLLISIONS cont... • Random Delay Time achieved by Truncated Binary Exponential Backoff • Delay Time Calculated by using the Nodes unique Network Address • At 80% Utilization Delays become noticable Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 18 Ethernet CSMA/CD Carrier Sense I’m listening I’m listening I’m listening I’m listening CSMA/CD Normal Operation Channel is free! I’ll transmit!! 1 2 3 4 5 CSMA/CD Normal Operation Is this for me? YES! 1 2 3 4 5 CSMA/CD - Collisions Channel is free! I’ll transmit!! 1 2 3 4 5 CSMA/CD Collisions OOPS!!! There was a collision! 1 2 3 4 5 CSMA/CD Collisions Channel is free! I’ll transmit!! 1 2 3 4 5 CSMA/CD Collisions Channel is free! I’ll transmit! 1 2 3 4 5 CSMA/CD Collisions OOPS!!! There was a collision! 1 2 3 4 5 FRAME TYPES • ETHERNET II -- 1980 -- (DIX Standard) • ETHERNET IEEE 802.3 -- 1985 Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 27 Ethernet II IEEE 802.3 Preamble Preamble 7 Octets 8 Octets Start Frame 1 Octet Destination 6 Octets Destination 6 Octets Source 6 Octets Source Address 6 Octets Type Length 2 Octets 2 Octets Data Unit LLC Data 46-1500 Octets 46-1500 Octets FCS FCS Ethernet84 OctetsCopyright 1998, John T. Gorgone, All Rights4 Reserved Octets 28 OSI MODEL NETWORK 802.2 DATA LINK 802.3 802.5 PHYSICAL Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 29 Bandwidth Demand • 1990’s Desktop Application Software becomes more powerful • Shared 10 Mbs Pipes become Bottleneck • Employ Switching Technology to Alleviate Bandwidth Crunch Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 30 Switched Ethernet • Replaces Existing Hubs • Establishes a Momentary Circuit between 2 Network Nodes • Switched Hubs Allow Each Device on the Network the Ability to Utilize All of the Available Bandwidth Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 31 FAST ETHERNET • Emerged in 1994 (100BASET) • Ability to Transmit Data at 100 Mbps • Utilizes the Same Protocols as Ethernet • Bus Topology • Half and Full Duplex Technology Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 32 Components of Fast Ethernet • Physical medium - different from Ethernet • Frame format - Same as in Ethernet Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 33 Fast Ethernet - Physical Medium 100BaseTX - Twisted Pair • Requires two pairs high quality wires • One pair for transmission and one pair for reception • Can support full duplex Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 34 Fast Ethernet - Physical Medium 100BaseT4 - Twisted Pair Requires four pairs ordinary quality wires • Each pair is bi-directional • Half duplex technology Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 35 Fast Ethernet - Physical Medium 100BaseFX - Fiber Optics • Requires one pair of cable • One cable for transmission and one cable for reception • Can support full duplex Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 36 Fast Ethernet Technology - Meeting the Current Need Ethernet Fast Ethernet Applications No change Applications Management No change Management CSMA/CD MAC No change CSMA/CD MAC Customer Choice Customer Choice Thin Coax Four Pair UTP Thick Coax (100BASE-T4) (Cat 3,4,5) (10BASE 5) (10BASE 2) Fiber TP - (10BASE- Fiber 2 Pair UTP,STP (10BASE-F) T) (100BASE-FX) (100BASE-TX) (Cat 5) (Cat 3,4,5) CSMA/CD -- Fast Ethernet • As the Speed of a Network Increases so does the opportunity for collisions • Shortest Transmission Unit must be 512 Bits • Delay caused by Network must be shorter than time to Transmit 512 Bits Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 38 Propogation Delay • The slowing of an Electronic Signal caused by Network Equipment • Hubs, Cables, and NIC’s all cause Propogation Delay • Without Proper Network Design Propogation Delay can cause Network Failures Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 39 Network Design • Each Network Device has a specified Propogation Delay measured in Bit Times • Sum of Bit Times between the two farthest Nodes must be less than 512----Bit Time Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 40 Gigabit Ethernet • Fast Ethernet has become a Bottleneck at the Backbone and Server Level • Promises to Deliver Data at 1000 Mbps • Compatible with Existing 10/100 Ethernet Standards • Uses the Standard 802.3 Frame Format Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 41 Gigabit Ethernet Goals • Speed of 1,000 Mbps • Keep Ethernet frame format • Keep Ethernet CSMA/CD access rules • Full and half duplex operation • Support fiber media and copper media • Fully compatible with Ethernet and Fast Ethernet Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 42 Highly Anticipated • Scaleabiliy • Low-Cost-of-Ownership • Flexibility to Handle New Applications • Straightforward Migration w/o Disruption to Existing Infrastructure • Rides the tremendous growth of Fast Ethernet and provides a Server and Backbone Solution Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 43 Gigabit Technology- Meeting Tomorrow’s Needs Fast Ethernet Gigabit Ethernet Applications No change Applications Management No change Management CSMA/CD MAC Compatible CSMA/CD MAC Customer Choice Customer Choice Four Pair UTP Twinax Long WL Fiber (100BASE-T4) (Cat 3,4,5) (1000BASE CX) (1000BASE-LX) Fiber 2 Pair UTP,STP Short WL Twisted Pair (100BASE-FX) (100BASE-TX) (Cat 5) Fiber (1000BASE-T) (1000BASE-SX) Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 44 Gigabit : CSMA/CD • Political Suicide not to incorporate CSMA/CD • Carrier Extension used to ensure Collisions can be detected • Packet Bursting allows Nodes to send multiple Frames back to back Ethernet8 Copyright 1998, John T.