IEEE 802.3 Ethernet IEEE 802.3u Fast Ethernet IEEE 802.3z Gigabit Ethernet ANSI X3T9 Fibre ...

72 Pages·2001·1.02 MB·English

IEEE 802.3 Ethernet
IEEE 802.3u Fast Ethernet
IEEE 802.3z Gigabit Ethernet
ANSI X3T9 Fibre Channel
Ethernet – Table of Contents
Part 1: IEEE 802.3 Ethernet
Part 2: IEEE 802.3u Fast Ethernet
Floor 4
Ethernet / Fast
Ethernet Switch
Part 3: IEEE 802.3z Gigabit Ethernet
Floor 3
Hub Stack
Bridge / Router WAN
Fast
Ethernet Switch Floor 1
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Ethernet – History
• Developed by Xerox Palo Alto Research Centre
• First published by Digital Equipment, Intel, and Xerox as DIX (DEC, Intel,
Xerox) standard
• Strongly changed and standardised by IEEE in the IEEE 802.3
• Therefore, two different versions are existing:
– Ethernet version 2 (DIX)
– IEEE 802.3
– differences are mainly in the Media Access frame
• Topology of an Ethernet is logically (mostly physically, too) a bus
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Ethernet – Technological Overview
• A lot of standards exist for different Ethernet versions:
– 1Base5 (Starlan), 10Base5 (Ethernet), 10Base2 (Cheapernet)
– 10BaseT, 10BaseF, 10Broad36
– 100BaseTX, 100BaseFX, 100BaseT2, 100BaseT4
– 1000Base-LX, 1000Base-SX, 1000Base-CX, 1000Base-T
– 100BaseVG, 100VG-AnyLAN
• First number identifies transfer rate (1=1MBit/s, 10=10MBit/s, ...)
• Base = baseband transmission, Broad = broadband transmission
• Last digit, number, or character identifies characteristics of the
transmission medium:
– T = twisted pair, FX/LX/SX = fibre optics, CX = shielded balanced
copper, T4 = 4 pair twisted pair, T2 = 2 pair twisted pair
– length of a segment - 2=185m, 5=500m
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Part 1: Survey
Part 1: IEEE 802.3 Ethernet
– Physical Layer
– Medium Access
– Configuration Rules
Part 2: IEEE 802.3u Fast Ethernet
Part 3: IEEE 802.3z Gigabit Ethernet thick coax
segment
(500m max)
coax
MAU tap
(MDI)
15-pin AUI
connector
transceiver
AUI cable
(50m max)
Ethernet interface male "N" connector
with external MAU
50 Ohm terminator
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IEEE 802.3 Ethernet – Introduction
Applications
Management
CSMA/CD MAC
AUI Interface
10Base5 10Base2 10Base-T 10Base-F
(Thick Coax) (Thin Coax) (UTP cat 3,4,5) (Fibre)
Ethernet Physical Layer (PHY) Options
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Physical Layer
• Tasks of the physical layer defined as:
– send and receive bit streams
– collision detection
– encoding and decoding of signals
– generation of the preamble
– generation of clocks for synchronisation
– testing of the transmission of data from the station up to the Medium
Access Unit (MAU)
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Physical Layer (cont.) – Architectural Model
Higher Protocol Layer
Logical Link Control (LLC)
Medium Access Control (MAC)
PLS
r
e
y standardised
a
I
L U in IEEE 802.3

l A
a
c
i
s
y
h
P
PMA
U
A
M
MDI
transmission medium
PLS Physical Signalling Sub-layer MDI Medium Dependent Interface
AUI Attachment Unit Interface MAU Medium Attachment Interface
PMA Physical Medium Attachment
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Medium Access – CSMA/CD
• Shared medium access is realised with Carrier Sense Multiple Access
with Collision Detection (CSMA/CD)
– each station is listening to the carrier (carrier sense)
– if no transmission takes place, stations can send data to any other
station (multiple access)
– if two or more stations send data at the same time, each station has
to stop further transmission (collision detection)
– after a certain time (random for each station), stations can try to send
data again
• CSMA/CD needs
– multiple stations connected to a segment (multiple access)
– sense of the carrier before data is sent (carrier sense)
– sense of the carrier during data transmission (collision detection)
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Medium Access (cont.) – Domains
Bridge / Repeater /
Router
Switch Hub
Ethernet Ethernet Ethernet Ethernet
Collision Domain
Broadcast Domain
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