Gigabit Ethernet

Home , 10BASE2, 10BROAD36, Gigabit Ethernet

Ethernet Technologies and Gigabit Ethernet

Professor John Gorgone

• Origins of Ethernet • Ethernet 10 MBS • Fast Ethernet 100 MBS • Gigabit Ethernet 1000 MBS • Comparison Tables • ATM VS Gigabit Ethernet

• 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

• 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

• 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

• A standard for LANs • The standard covers two layers of the ISO model – Physical layer – Data link layer

• Transmission speed of 10 Mbps • Originally, only baseband • In 1986, broadband was introduced • Half duplex and full duplex technology • Bus topology

• Physical Medium

• Medium Access Control

• Ethernet Frame

10 BASE T

SPEED TRANSMISSION MAX TYPE LENGTH

• Thick Ethernet (coaxial) 10BASE5 • Thin Ethernet (coaxial) 10BASE2 • UTP (twisted pair) 10BASET

– CATEGORY 5 ------100 MBS • Fiber 10BASEF • Broadband (coaxial) 10BROAD36

10Base5 - Thick Coaxial

• Original Ethernet • Coaxial cable, 0.25 inch in diameter • Segments length up to 500 m

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

10BaseT - Twisted Pair

• Commonly used for telephones; very economical • Twisted pair, unshielded • Segments length up to 150 m

10BaseF - Fiber Optics

• Excellent for electrical isolation • Fiber optics cable • Segments length up to 2,000 m

10Broad36 - Coaxial Broadband

• Covers greater distances at greater cost • Coaxial cable, broadband • Segments length to 3,600 m

• Access to shared Channel achieved by CSMA/CD

• CARRIER SENSE

• MULTIPLE ACCESS

• COLLISION DETECTION

• 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

• 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

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

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

• 1990’s Desktop Application Software becomes more powerful

• Shared 10 Mbs Pipes become Bottleneck

• Employ Switching Technology to Alleviate Bandwidth Crunch

• 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

• Emerged in 1994 (100BASET)

• Ability to Transmit Data at 100 Mbps

• Utilizes the Same Protocols as Ethernet

• Bus Topology

• Physical medium - different from Ethernet

• Frame format - Same as in Ethernet

100BaseTX - Twisted Pair

• Requires two pairs high quality wires • One pair for transmission and one pair for reception • Can support full duplex

100BaseT4 - Twisted Pair

Requires four pairs ordinary quality wires • Each pair is bi-directional • Half duplex technology

100BaseFX - Fiber Optics

• Requires one pair of cable • One cable for transmission and one cable for reception • Can support full duplex

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

• 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

• 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

• 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

• 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

• 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)

• 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

• Created to Develop the Gigabit Draft Standard------March 98

• Initial Standard focuses on Single and Multi-mode Fiber along with Short Haul Copper

• Faced with the Challenge of bringing Gigabit Speeds to UTP CAT 5

• CAT 5 presently used in 70% of all Network Installs

• Must Deal with the Problems of Attenuation and Crosstalk

1000 Mbps MAC (Media Access Control) 802.3z CSMA/CD Ethernet

GMII (AUI Equivalent)

1000Base-CX 1000Base-T 1000Base-SX 1000Base-LX STP Cat 5 UTP Multimode Singlemode (150ohm) Fiber Fiber

25m 100m 500m 3km

Note: Distances are IEEE 802.3z and IEEE 802.3ab goals

• PAM-5 coding used to increase the amount of Information sent on each Symbol

• 4D 8-state Trellis Forward Error Correction to offset the impact of Noise and Crosstalk

• Pulse Shaping used to maximize the Signal to Noise Ratio

• Differential Mode Delay ( Multi-Mode ) – Single Laser Light Creates a False Pulse in another Light Pathway – The 2nd Pulse will cause Errors in Transmission • Conditioned Launch – Spreads Light Evenly throughout Modes

• Speed – Servers Become the New Bottleneck • Flow Control – 802.3X – Wandering Congestion • Quality of Service – 802.1p------Working on Priority Queuing

Fast Ethernet Gigabit Ethernet Ethernet Design Goals

Data Rate 10Mbps 100 Mbps 1000 Mbps

Cat 5 UTP 100 m (min) 100 m 100 m

STP/Coax 500 m 100 m 25 m

Multimode Fiber 412 m (hd) 2 km 2 km (fd) 200-550 m Single Mode 25 km 20 km 3 km

Switch Existing or Network Router

Full-Duplex 500 m Multimode Fiber 3 km Singlemode Fiber Switch Switch Copper Full Duplex Multimode Fiber 25 m 25 m 25 m 500 m 500 m 500 m

NIC NIC NIC 100BT 100BT 100BT Switc Switc Switc 100 m h h h

NIC NIC NIC NIC NIC NIC NIC NIC NIC

• Building Backbone 10 Mb/s • Gbps uplinks with fiber to the 10/100 Mb/s wiring closets 1 Gb/s

10/100 Mb/s • Gbps switching with copper or short distance fiber in the building data center WA Switch N • Routing and ATM to the wide area network ATM

Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 54 Campus Applications • Campus Backbone • Gbps links with fiber Switch Switch Switch between buildings • Gbps switching with Campus 1 Gb/s Center copper or short distance fiber in the campus data Switch Switch center • Routing and ATM to the Central Switch wide area network AT M

Switch Switch Switch WAN

1400

1200

1000

800 Shared Hubs LAN Switches 600 Routers 400

200

0 1997 1998 1999 2000

2500

2000

1500 Shared Hubs LAN Switches 1000 Routers

500

0 1997 1998 1999 2000

Ethernet Fast Ethernet Gigabit Ethernet

First Shipment 1982 1994 1997

Speed 10 Mbps 100 Mbps 1,000 Mbps

Physical Medium 10Base5 100BaseTX Will support fiber 10Base2 100BaseT4 media and, if 10BaseT 100BaseFX possible, copper 10BaseF media 10Broad36

Access Control CSMA/CD CSMA/CD CSMA/CD

Frame Format destin: 6 bytes Same as Will probably source: 6 bytes Ethernet change length: 2 bytes data: 46 to 1500 bytes error check: 4 bytes

Ethernet Fast Ethernet Gigabit Ethernet

Applications File sharing, Workgroup, Large image files, printer sharing client / server, multimedia, database access intranet access, data warehouse access

Network Mgmt tools, Full compatible Full compatible management mgmt apps, mgmt platform

Network Operating System, Full compatible Full compatible infrastructure protocols

Hardware Ethernet hubs, Changes in hubs, Changes in hubs, switches, switches, switches, cards (NIC) cards (NIC) cards (NIC)

• Designed to Transfer Voice,Video, Audio and Data • Employs Cell Switching Technology – 53 Byte Cells – 48 Byte Payload and 5 Byte Header – Top Speed of 622 Mbps • Switch Connectivity – Dedicated Bandwidth per Connection – Switching is much Faster than shared Bus

• Adaption Layer-----AAL – Inserts and Extracts Info into 48 Byte Payload • ATM Layer – Adds and Removes 5 Byte Header to Payload • Physical Layer – Converts data to appropriate electrical or optical format Ethernet8 Copyright 1998, John T. Gorgone, All Rights Reserved 61 ATM VS Gigabit

• Gigabit Advantages • Seamless Migration w/o extensive training • Simplicity, Massive Bandwidth, and Compelling Price---ATM Switch-13,738 vs Gigabit Switch--3,125 • Provides Twice the Bandwidth at 1/4 the Price

• Proven Technology that is Available Today

• Far Superior Quality of Service

• Ability to Choose Different Classes of Service

• Internet 2 is being Designed around ATM

• Gigabit Ethernet’s ability to work with Existing Ethernet Legacy Systems • Simplify Network Management – 10Mbps Desktop, 100Mbps Complex Applications, and 1Gbps at the Backbone • Price

• Gigabit Ethernet will be an excellent solution if you pushing Large Amounts of Data However…

• ATM is far superior if you are in the Image and Sound business