Gigabit Ethernet

1
Gigabit Ethernet

• Freeha Khan
• Is 8040
• Data Communication Theory and Practice

2
Ethernet History

• Ethernet has evolved from a 4800bps contention
  based radio channel transmission system to he
  most popular local area networking standard
• The idea of shared data transmission channel
  began in 1960s by Norman Abramson at University
  of Hawaii
• Todays Ethernet started in 1972 by Bob Metcalfe
  at Xerox research center - PARC

3
Ethernet Evolution

• Initially, the most commonly installed Ethernet
  systems were called 10BASE-T, which gave way to
  100BASE-T, also known as fast Ethernet, which
  could (theoretically) transmit at 100 mbps
• Fast Ethernet now giving up its place at the
  backbone to Gigabit Ethernet which can
  (theoretically) provide a bandwidth of a billion
  bits per second

4
Ethernet Evolution

• Evolution and comparison

5
Gigabit Ethernet

• In 1996, twenty eight companies formed the
  Gigabit Ethernet Alliance
• Gigabit Ethernet is an extension of the highly
  successful 10mbps (10base-t) Ethernet and 100mbps
  (100base-t) fast Ethernet standards for network
  connectivity
• Gigabit Ethernet incorporates enhancements that
  enable fast optical fiber connections at the
  physical layer of the network

6
Specifications

• CSMA/ CD MAC engine
• Cabling base standards
• 1000BASE-SX
• 1000BASE-LX
• 1000BASE-CX
• 1000BASE-T

7
Standards
1000 Mbps CSMS/CD MAC
IEEE 802.3ab standard
IEEE 802.3z standard
Two pairs of twinax
Two standards of MMF or SMF fiber
Two standards of MMF
Four pairs of cat 5 UTP or better
8
Gigabit Ethernet MAC

• It uses the official 802.3 frame format
• Operates in both half- and full-duplex mode
• Slot time has increased to 512 bytes
• Burst mode multiple smaller frames can be
  transmitted continuously up to a maximum of 8192
  bytes of data

9
Frame Format
10
Gigabit Ethernet PHYs

• The 802.3z Gigabit Ethernet includes three PHYs
  1000BASE-SX and LX to support fiber optic cable
  and 1000BASE-CX for shielded 150-ohm copper cable
• 802.3ab 1000BASE-T physical layer, which enable
  Gigabit Ethernet over category 5 UTP

11
1000BASE-SX

• Targeted at cost sensitive
• Shorter backbone
• Horizontal connection
• 850nm short-wavelength optical diodes
• Multimode fiber (MMF)
• 220 to 550 meters distance depending on the type
  of fiber cable used

12
1000BASE-LX

• Targeted at longer backbone
• Vertical connections
• It can use either SMF or MMF
• For LX, using MMF
• 550m, full duplex
• For SX, using SMF
• 5000m

13
1000BASE-CX

• Designed for short interconnects of hubs,
  switches, or routers in wiring closet
• 150-? twinax cabling
• Max cable length is 25 meters
• Two types of connectors
• High-Speed Serial Data Connector (HSSDC)
• Nine-pin D-subminiature connector

14
Physical Layer Implementations
15
1000BASE-T

• It uses all four pairs of Cat 5 cabling
• Simultaneous transmission and reception on all
  four pairs Dual Duplex
• High symbol rate of 125MHz

16
Advantages

• 10 times faster than fats Ethernet
• 100 times faster than Ethernet
• Low implementation cost
• Compatible with the most popular networking
  architecture

17
Advantages

• Increased network performance levels
• Increased network scalability
• Full duplex
• Switched
• No inherent distance limitations

18
Advantages

• Relatively simple installation and maintenance
• Fast optical fiber connections at the physical
  layer of the network
• Provides a tenfold increase in MAC (media access
  control) layer data rates to support video
  conferencing, complex imaging and other
  data-intensive applications

19
References

• Business Data Communication, William Stallings,
  Fourth Edition
• Switched, Fast and Gigabit Ethernet, Robert
  Breyer Sean Riley
• http//www.aj.com
• http//www.10gea.org
• http//www.betanet.co.uk/