IEEE 802.3 Ethernet IEEE 802.3u Fast Ethernet IEEE 802.3z Gigabit

Transcription

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
Fast
Ethernet Switch
Broadband Network Technologies
Bridge / Router
WAN
Floor 1
IEEE 802.3 Ethernet
2
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
IEEE 802.3 Ethernet
3
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
IEEE 802.3 Ethernet
4
Part 1: Survey
– Physical Layer
– Medium Access
– Configuration Rules
thick coax
segment
(500m max)
MAU
coax
tap
(MDI)
15-pin AUI
connector
transceiver
AUI cable
(50m max)
Ethernet interface
with external MAU
male "N" connector
50 Ohm terminator
IEEE 802.3 Ethernet
5
IEEE 802.3 Ethernet – Introduction
Applications
Management
CSMA/CD MAC
AUI Interface
10Base5
(Thick Coax)
10Base2
(Thin Coax)
10Base-T
(UTP cat 3,4,5)
10Base-F
(Fibre)
Ethernet Physical Layer (PHY) Options
IEEE 802.3 Ethernet
6
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)
IEEE 802.3 Ethernet
7
Physical Layer (cont.) – Architectural Model
Higher Protocol Layer
Logical Link Control (LLC)
Medium Access Control (MAC)
standardised
in IEEE 802.3
AUI
PMA
MAU
Physical Layer
PLS
MDI
transmission medium
PLS
AUI
PMA
Physical Signalling Sub-layer
Attachment Unit Interface
Physical Medium Attachment
MDI
MAU
Medium Dependent Interface
Medium Attachment Interface
IEEE 802.3 Ethernet
8
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)
IEEE 802.3 Ethernet
9
Medium Access (cont.) – Domains
Bridge /
Switch
Router
Ethernet
Ethernet
Repeater /
Hub
Ethernet
Ethernet
Collision Domain
Broadcast Domain
IEEE 802.3 Ethernet
1
Medium Access (cont.) – IEEE 802.3 Frames
IEEE 802.3 Ethernet MAC frames
PA
SFD
DA
SA
LEN
LLC
7
1
6
6
2
3/4
PA
DA
SA
SFD
preamble
destination address
source address
start frame delimiter
LLC
PAD
FCS
LEN
Data
PAD
variable
FCS
4
logical link control
padding
frame check sequence (CRC-32)
length
IEEE 802.3 Ethernet
1
Configuration Rules
•
Basically two models exist for the configuration of multi-segment
Ethernet networks:
1. A model employing conservative calculations
2. A model employing IEEE standardised configuration aids with two
phase calculation (first the correct round trip signal propagation,
than the amount of Interframe Gap shrinkage)
•
System not built with these guidelines can work, but usually not for a
long time
•
Especially a growing network (by size or traffic load) should not violate
this recommendations (IEEE 802.3)
IEEE 802.3 Ethernet
1
Configuration Rules (cont.) – Model 1
R
10Base-FL link
500m
10Base-5
mixing
10Base-FL link
500m
500m
10Base-5
mixing
R
R
500m
DTE 1
R
DTE 2
10Base-T link
100m
DTE 3
185m
10Base-2 mixing
R
Repeater
IEEE 802.3 Ethernet
1
Configuration Rules (cont.) – Model 2
•
Defines two sets of methods, which have to be performed both
•
First set ensures that the round trip signal propagation is within the limits
•
Second set verifies the amount of Interframe Gap shrinkage
•
A simplified network topology (Generalised Transmission Path Model) is
used to for the path delay calculation
DTE
1
MAU
MAU
Repeater
left segment
MAU
MAU
middle segment
Repeater
MAU
MAU
DTE
2
right segment
IEEE 802.3 Ethernet
1
– Introduction
– 100Base-T Overview
– 100Base-TX
– 100Base-FX
– 100Base-T4
Ethernet / Fast
Ethernet Switch
Ethernet / Fast
Ethernet Switch
Fast Ethernet Hub
IEEE 802.3 Ethernet
1
Fast Ethernet – Technological Overview I
•
Two different technologies exist for 100MBit/s Ethernet
– IEEE 802.3u 100Base-T (100Base-TX, 100Base-FX, 100Base-T4,
100Base-T2)
– IEEE 802.12 100VG-AnyLAN
•
100Base-T
– supports the common Ethernet mechanisms (CSMA/CD)
•
100VG-AnyLAN
– creates an entirely new medium access control mechanism
– is based on hubs that control access to the medium using a demand
priority
– further extended to allow to transport token ring frames
IEEE 802.3 Ethernet
1
Fast Ethernet – Technological Overview II
100 MBit/s Ethernet
100VG-AnyLAN
100Base-T
100Base-T2
100Base-X
100Base-TX
100Base-4
100Base-FX
IEEE 802.3 Ethernet
1
IEEE 802.u Fast Ethernet
•
Aims of the IEEE 802.3u Fast Ethernet working group
– support of CSMA/CD with bit rate of 100 MBit/s
– identical MAC frame format
– support of twisted pair and fibre optics as physical medium
– interoperability between 10Base-T and 100Base-TX components
•
Fast Ethernet Consortium develops technology and is accepted by the
IEEE 802.3u working group
•
The Fast Ethernet Consortium was formed in December of 1993 and is
one of the consortiums at the University of New Hampshire Inter
Operability Lab (IOL). The Consortium was formed through the cooperative agreement of vendors interested in testing Fast Ethernet
products.
IEEE 802.3 Ethernet
1
IEEE 802.u Fast Ethernet (cont.) – Overview
Applications
Management
CSMA/CD MAC
MII Interface
100Base-FX
(Fibre)
100Base-TX
(UTP cat 5)
100Base-T4
(UTP cat 3,4,5)
Fast Ethernet Physical Layer (PHY) Options
IEEE 802.3 Ethernet
1
Physical Layer – 100Base-X
Scheme of the 100Base-X standard
LLC
MAC
Reconciliation
100Base-X repeater
MII
PCS
PCS
Physical
Layer
PMA
PMD
MDI
Medium
PCS
PMA
PMA
PMD
PMD
MDI
MDI
Medium
IEEE 802.3 Ethernet
2
Physical Layer (cont.) – 100Base-T4
Scheme of the 100Base-T4 standard
LLC
MAC
Reconciliation
MII
PCS
PMD
MDI
Medium
IEEE 802.3 Ethernet
2
Physical Layer (cont.) – 10/100 MBit Hub
Scheme of a Fast Ethernet hub supporting different media
10Base-T / 100Base-TX repeater
Reconciliation
Reconciliation
MII
MII
PCS
Physical
Layer
PCS
PMA
AUI
PMD
PMA
MDI
AUI
PMA (= MAU)
MDI
Medium
Medium
100 MBit/s
10 MBit/s
PLS
MDI
Medium
10 MBit/s
IEEE 802.3 Ethernet
2
Media System
•
•
•
•
100Base-T is ten times faster than 10Base-T
Common 10Base-T aspects are unchanged
– frame format and the amount of data of a frame
– media access control
Mechanisms for Auto-Negotiation of media speed added
– enables support of dual-speed Ethernet interfaces (10 and 100
MBit/s)
Block diagram of 100Base-T components:
Data Terminal
Equipment
(DTE)
port
Medium Independent
Interface (MII)
40-pin connector
Physical
Layer
Device (PHY)
Medium
Dependent
Interface (MDI)
Physical
Medium
optional
IEEE 802.3 Ethernet
2
100Base-TX – Components I
class II four port
100Base-TX repeater hub
PHY
PHY
PHY
PHY
II
R
eight pin
plugs
twisted pair segment
(100m max of data graded
UTP cat 5 cable)
PHY
eight pin
jack MDI
Ethernet interface
(100Base-TX)
IEEE 802.3 Ethernet
2
100Base-TX (cont.) – Components II
•
•
100Base-TX segments are link segments
A link segment is defined as a point-to-point medium
– connects two and only two MDIs
– smallest network would consist of two computers
•
Typical installation uses multiport repeater hubs or packet switching hubs
– provides a connection between a larger number of link segments
– NIC on one end, hub on the other end of the segment
– hubs can connect as many segments as ports available
– computers all communicate via the hub
•
•
Segment up to 100m
Two 100m segments segments can be connected through a single
Class I or Class II repeater
System with a total diameter of 200 meters between DTEs
•
IEEE 802.3 Ethernet
2
100Base-T (cont.) – Repeater I
Data Circuit Equipment (repeater, hub)
•
Ethernet ports on repeaters do not use an Ethernet interface
– A repeater port connects to the Fast Ethernet media system with the
same PHY and MDI equipment
– moving the signals directly from segment to segment, therefore, do
not contain Ethernet interfaces (since they do not operate at the level
of Ethernet frames)
– a repeater hub may be equipped with an Ethernet interface to
provide a way to communicate with the hub over the network (allows
a vendor to provide a management interface in the hub)
•
Two kinds of repeaters in the 100Base-T system (labelled with the
Roman number "I" or "II" centred within a circle)
– Class I
– Class II
IEEE 802.3 Ethernet
2
100Base-T (cont.) – Repeater II
Class I repeater have larger timing delays
– operates by translating line signals on an incoming port to digital
form
– then retranslating them to line signals when sending them out on the
other ports
– repeats signals between media segments that use different signalling
techniques (e.g. 100Base-TX/FX and 100Base-T4 segments)
– only one Class I repeater can be used in a given collision domain
when maximum cable lengths are used
•
•
Class II repeater is restricted to smaller timing delays
– immediately repeats the incoming signal to all other ports
– connected only to segment types that use the same signalling
technique a maximum of two Class II repeaters can be used within a
given collision domain when maximum cable lengths are used
Segment types with different signalling techniques cannot be mixed
together in a Class II repeater hub
IEEE 802.3 Ethernet
2
100Base-TX (cont.) – Link Integrity Test
•
PHY continually monitors the receive data path for activity
– checks that the link is working correctly (also in idle periods)
– signalling system is based on the ANSI FDDI signalling
•
Twisted-pair transceivers that use 8-pin MDI connectors also send and
receive link pulses
– called Fast Link Pulses (FLP)
– used in the Auto-Negotiation mechanism
– allows a multi-speed hub to detect the speed of operation of an
Ethernet device
– hub can adjust the speed of its ports accordingly
IEEE 802.3 Ethernet
2
100Base-FX – Components
class II 100Base-FX
fibre optic repeater hub
R
II
TX RX TXRX TXRX
FO link
to another
FO station or
repeater hub
TX
RX
Ethernet interface
(100Base-FX)
SC, ST, or
FDDI fibre optic connector
IEEE 802.3 Ethernet
2
100Base-T4 – Components
class II four port
100Base-T4 repeater hub
PHY
PHY
PHY
PHY
II
R
eight pin
plugs
twisted pair segment
(100m max of four pair
UTP cat 3,4,5 cable)
PHY
eight pin
jack MDI
Ethernet interface
(100Base-T4)
IEEE 802.3 Ethernet
3
100Base-T4 - Components
•
•
•
Old „voice-grade“ twisted pair (Cat3) has high attenuation and
electromagnetic radiation
UTP Cat3 is only defined up to 16 Mbit/s
Radiation is limited by the authorities above 30 MHz
•
•
Therefore 4 pairs working in parallel at 25 Mbit/s
Special attention ís paid to signal encoding
IEEE 802.3 Ethernet
3
Migration – From Ethernet to Fast Ethernet
•
Fast Ethernet is compatible with Ethernet
– shared medium, too
– CSMA/CD is the same
– old cabling can be used, if UTP cat 5
– 10Base-T network cards can be connected to 100Base-T equipment
•
Differences
– new network cards needed (dual cards available)
– coax cable no longer supported
– integration can be accomplished with switches rather then routers
– maximum hop count between stations (repeater, hub) is 2 (Ethernet:
4), larger networks have to employ bridges, switches, or routers
– maximum network diameter between two stations in the same
segment is 205 m (twisted pair)
IEEE 802.3 Ethernet
3
Migration (cont.) – Cable Pinout
•
100Base-TX Cable Pinout
Desktop
1
2
3
4
5
6
7
8
•
Hub
Transmit (1&2)
Receive (3&6)
1
2
3
4
5
6
7
8
100 Base-T4 Cable Pinout
Desktop
1
2
3
4
5
6
7
8
Hub
Transmit (1&2)
Receive (3&6)
Bi-directional (4&5)
1
2
3
4
5
6
7
8
Bi-directional (7&8)
IEEE 802.3 Ethernet
3
Migration (cont.) – Switched vs. Fast Ethernet
Fast Ethernet
Switched Ethernet
Existing
Workgroups
Seldom makes sense to the desktop;
use for servers only:
• Most existing PCs cannot take
advantage of 100 MBit/s
• Costs of changing adapters
Obvious upgrade path:
• Low cost; no adapter change
• Leverages existing PCs
• No cable change
• Multimedia capable
New
Workgroups
For power users and peak bandwidth
needs
• 100MBit/s peak bandwidth for
CAD/CAM, graphics, 3D Modelling,
etc.
• Only slightly higher costs than
switched 10MBit/S
• Ideal for PCs and PCI PCs and UNIX
workstations
Or standard business applications
and aggregate bandwidth needs
• Lower costs
• Standard Ethernet cabling
• Ideal for ISA, PC-Card (PCMCIA)
PCs
Summary
Peak performance – new
Continuous network use – ISA PCs
PCs/workstations with large file transfers and installed base
IEEE 802.3 Ethernet
3
Migration (cont.) – Small Fast Ethernet Collapsed Backbone
Ethernet Hub
shared 10MBit/s
switched 10MBit/s
switched 100MBit/s
Ethernet Hub
Ethernet / Fast
Ethernet Switch
shared 100 MBit/s
Fast Ethernet Hub
IEEE 802.3 Ethernet
3
Migration (cont.) – Switched Ethernet with Fast Ethernet
Ethernet / Fast
Ethernet Switch
Ethernet / Fast
Ethernet Switch
switched 10MBit/s
switched 100MBit/s
shared 100 MBit/s
Fast Ethernet Hub
IEEE 802.3 Ethernet
3
Migration (cont.) – High Performance Workgroups
Floor 4
Ethernet / Fast
Ethernet Switch
Floor 3
Hub Stack
switched 10MBit/s
switched 100MBit/s
shared 100 MBit/s
Floor 2
Hub Stack
FDDI
Fast
Ethernet Switch
Bridge / Router
Floor 1
WAN
IEEE 802.3 Ethernet
3
Migration (cont.) – Comprehensive Fast Ethernet Integration
Floor 4
Ethernet / Fast
Ethernet Switch
Floor 3
shared 10MBit/s
Ethernet Hub
switched 10MBit/s
switched 100MBit/s
shared 100 MBit/s
Floor 2
Fast
Ethernet Switch
Fast
Ethernet Switch
LAN Switch
FDDI
Bridge / Router
WAN
Floor 1
IEEE 802.3 Ethernet
3
Migration (cont.) – Scale Fast Ethernet and an FDDI Backbone
Floor 2
Floor 2
Hub with 100 MBit/s
downlink
Hub with 100 MBit/s
downlink
Floor 1
Floor 1
Hub Stack
Hub Stack
Fast
Ethernet Switch
Fast
Ethernet Switch
LAN Switch with
support for bridging,
FDDI concentration,
and IP routing
FDDI
backbone
Bridge / Router
switched 10MBit/s
switched 100MBit/s
shared 100 MBit/s
IEEE 802.3 Ethernet
3
Topology Rules
•
Maximum Network Diameter
Repeater
Class
I
II
II
•
Qty. Twisted Pair
Fibre
Twisted Pair /Fibre
TX/T4
100Base-FX
TX/FX
T4/FX
1
200 m
272 m
260.8 m
231 m
656 ft.
892.2 ft.
855.4 ft.
57.7 ft.
1
200 m
320 m
308.8 m
304 m
656 ft.
1,049.6 ft.
1,012.9 ft. 997.1 ft.
2
205 m
228 m
216.2 m
236.3 m
672.4 ft.
747.8 ft.
709.1 ft. 775.1 ft.
Maximum Cable Distances
Cable Type
Connecting
Length
Twisted Pair
Any two devices
100m
328 ft.
Fibre
Switch to Switch,
Server or PC
Half
Duplex
142 m
1,351.4 ft.
Full
Duplex
2 km
1.24 m i.
IEEE 802.3 Ethernet
4
Topology Rules (cont.)
MAC - MAC
412m fibre
Floor 100
100Base-T
Switch or Bridge
one repeater: 261m
(161m fibre + 100m UTP)
Floor 50
100Base-T
Class I hub
two repeaters: 205m
(typically 100m + 5m + 100m)
100m UTP
Floor 25
100m UTP
100Base-T
Class II hub
5m UTP
100m UTP
100Base-T
Class II hub
switched 100MBit/s
Bridge / Router
Switch
shared 100 MBit/s
IEEE 802.3 Ethernet
4
T
T
HYBRID
HYBRID
R
R
T
T
HYBRID
HYBRID
R
R
T
T
HYBRID
HYBRID
– The need for speed
– Functional Elements
– Architectural Model
– 1000Base-T
– Migration
R
R
T
T
HYBRID
HYBRID
R
R
IEEE 802.3 Ethernet
4
Gigabit Ethernet – The Need for Speed
Not-compressed
1.4 MBit/s
Compressed
192 kBit/s
Jitter
100 ms
Speech
64 kBit/s
4 – 32 kBit/s
400 ms
Video – HDTV
2 GBit/s
25 – 34 MBit/s
(MPEG-2)
3 – 6 MBit/s
(MPEG-2)
2 – 4 MBit/s
(MPEG-2)
112 kBit/s
(H.261)
50 ms
Audio (CD quality)
Video – studio quality
166 MBit/s
Video – TV quality
–
Video – video conference
quality
–
100 ms
100 ms
400 ms
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Protocol Stack
IEEE 802.2 LLC
IEEE 802.3
Ethernet
IEEE 802.3
CSMA/CD
IEEE 802.3
Physical Layer
IEEE 802.2 LLC
CSMA/CD or Full
Duplex MAC
FC-4 Upper Layer
Mapping
ANSI X3T11
Fibre Channel
8B/10B
Encode/Decode
FC-3 Common
Services
Serializer/
Deserializer
FC-2 Signalling
Connector
FC-1
Encode/Decode
FC-0 Interface
and Media
IEEE 802.3 Ethernet
4
Standardisation Timeline
1995
1996
HSSG
Formed
PAR
Drafted
1997
First Draft
Working
Group
Ballot
802.3z
Approved
1998
LMSC
Ballot
Standard
HSSG
PAR
LSMC
PAR
Approved
Higher Speed Study Group
Project Authorisation Request
LAN MAN Standards Committee
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Overview
Applications
Management
CSMA/CD MAC
GMII Interface
1000Base-CX
(Twinax)
1000Base-SX
(Short WL Fibre)
1000Base-LX
(Long LW Fibre)
1000Base-T
(Twisted Pair)
Gigabit Ethernet Physical Layer (PHY) Options
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Overview (cont.)
•
GbE is still Ethernet, only faster
•
New functional capabilities:
– Full-duplex operation
• Allows simultaneous two-way transmission
• The possibility of collisions is eliminated and the effective bandwidth is
doubled
– Flow Control
• Optional flow control allows to avoid receiver buffer overflows
– VLAN Tagging
• Allows the creation of virtual networks based on logical identification
rather than physical addresses
• Reduces the number of addresses that must be maintained in switch
tabels
• Allows to assign user priorities within an Ethernet
• Requires to change the frame format (if used, we are no longer
compatible to the other Ethernets)
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Functional Elements
Media Access Control (MAC)
full duplex and/or half duplex
Gigabit Media Independent Interface (GMII), optional
8B / 10 B
encoding / decoding
1000Base-T
encoder / decoder
1000Base-LX
LWL
Fibre Optic
1000Base-SX
SWL
Fibre Optic
1000Base-CX
Shielded Balance
Copper
1000Base-T
UTP
Category 5
SMF - 5 km
50µ MMF - 550 m
62,5µ MMF - 550 m
50µ MMF - 550 m
62,5µ MMF - 275 m
25 m
100 m
802.3z physical layer
802.3ab
physical layer
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Distance Specifications
9µ MMF
1000Base-LX
1300nm
50µ MMF
62.5µ MMF
50µ MMF
1000Base-SX
850nm
62.5µ MMF
1000Base-T
Copper(UTP)
1000Base-CX
Copper(twinax)
25m
Machine Room
100m
275m
>500m
Building Backbone
5km
Campus Backbone
IEEE 802.3 Ethernet
4
IEEE 802.3z Gigabit Ethernet – Architectural Model
Upper Layers
Data Link
Layer
Logical Link Control (LLC)
Media Access Control (MAC)
Reconciliation
Reconciliation
GMII
MII
Physical
Layer
PCS
PCS
PMA
PMA
PMD
PMD
MDI
MDI
Medium
Medium
100 MBit/s
1000 MBit/s
IEEE 802.3 Ethernet
5
IEEE 802.3z Gigabit Ethernet – Frame Transmission
•
7
Half-Duplex mode:
• Basically like classical Ethernet (Carrier sense, collision detection)
• But: the data frame is much shorter now!
• Two possible solutions:
• Increase the minimum frame length or
• Add non-data carrier-extension bits after the frame transmission
• The latter does not violate the standard, so it was chosen
1
PA SFD
6
6
DA
SA
2
3/4
variable
LEN LLC
Data
PAD
4
FCS
Extension
minFrameSize
slotTime
Late collision threshold (slot time)
Carrier duration
PA
DA
SA
SFD
preamble
destination address
source address
start frame delimiter
LLC
PAD
FCS
LEN
logical link control
padding
frame check sequence (CRC-32)
length
IEEE 802.3 Ethernet
5
IEEE 802.3z Gigabit Ethernet – Frame Transmission
•
Another possibility to extend the carrier is Frame bursting
– Allow a user to send a series of (small) packets without relinquishing
the control of the medium
MAC frame w. extension Interframe MAC frame
Interframe MAC frame
Burst limit
Carrier duration
– When the burst limit is reached, the last frame may be continued
without interruption
IEEE 802.3 Ethernet
5
1000Base-T – The Challenge
•
Transmitting 1000 MBit/s data stream over four pairs of UTP cat 5 cable
presents several design challenges due to:
– signal attenuation
– echo
– return loss
– crosstalk characteristics
• NEXT - Near-end Crosstalk
• FEXT - Far-end Crosstalk
• ELFEXT - Equal Level Far-end Crosstalk
•
•
Transmission systems operating on UTP cable must be capable of
withstanding radiated energy from other sources (AM, CD, short wave
radio)
Additional objective is to maximise the tolerance to background and
impulse noise (power line transients, electrical fast transients, Electrostatic discharge - ESD)
IEEE 802.3 Ethernet
5
1000Base-T (cont.) – The Design Approach
T
T
Insertion_Loss (f)
HYBRID
echo
HYBRID
250 MBit/s
R
R
T
HYBRID
FEXT_21
HYBRID
NEXT_21
T
250 MBit/s
R
T
HYBRID
FEXT_31
HYBRID
NEXT_31
T
R
T
HYBRID
FEXT_41
HYBRID
NEXT_41
T
R
250 MBit/s
Pair 3
R
250 MBit/s
250 MBit/s
Pair 2
R
250 MBit/s
250 MBit/s
Pair 1
250 MBit/s
Pair 4
R
IEEE 802.3 Ethernet
5
1000Base-T (cont.) – Transceiver
TX Magnetics
Pulse
Shaping
Auto
Negotiation
Resistive
Hybrid
DAC
PCS
Transmit
GMII
Synch
Tuning
Control
PLL
NC
NC
Delay Adj.
PCS
Receive
A/D
NC
NC
Σ
FFE
Viterbi
Decoder/
DFE
IEEE 802.3 Ethernet
5
1000Base-T (cont.) – 5-level PAM Coding
Binary signalling
1
0
+2
Symbol
Encoder
GMII
Baseband
Pulse
Shaping
+1
0
-1
125 MHz
-2
1000Base-T 5-level PAM
125 MHz, 5 levels
•
Four symbols transmitted simulataneously on the four pairs make up
an 8-bit octet (4D-PAM5 Trellis FEC code)
•
One octet is transmitted in only one baud, making up 125 Mbaud per
twisted pair
IEEE 802.3 Ethernet
5
Migration – Switch to Server Links
End User Connection
100 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
10 M
Switch
10 M
Switch
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100 MBit/s
100 MBit/s
Fast Ethernet Switch
Server Farm
End User Connection
100 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
10 M
Switch
10 M
Switch
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
Gigabit Ethernet Switch or Repeater
Gigabit
Ethernet NICs
1000 MBit/s
100 MBit/s
Server Farm
IEEE 802.3 Ethernet
5
Migration (cont.) – Switch to Switch Links
10 MBit/s
10 MBit/s
100 MBit/s
100 MBit/s
10 MBit/s
10 MBit/s
10 M
Switch
10 M
Switch
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100 MBit/s
10 MBit/s 10 MBit/s 10 MBit/s 100 MBit/s
100 MBit/s 10 MBit/s 10 MBit/s 10 MBit/s
10 M
Switch
10 M
Switch
10 M
Switch
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
10 M
Switch
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
Server Farm
End User Connection
End User Connection
100 MBit/s
100 MBit/s
End User Connection
1000 MBit/s
Server Farm
100 MBit/s
100 MBit/s
End User Connection
Gigabit Ethernet
Modules
IEEE 802.3 Ethernet
5
Migration (cont.) – Upgrading a Switched Backbone
End User Connection
100 MBit/s
100 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
10 M
Switch
10 M
Switch
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100
MBit/s
100 MBit/s Backbone
End User Connection
100 MBit/s
100 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
10 MBit/s
100 M
Repeater
100 M
Repeater
10 M
Switch
10 M
Switch
10 M
Switch
10 M
Switch
1000
MBit/s
1000
MBit/s
1000
MBit/s
1000
MBit/s
1000
MBit/s
1000
MBit/s
Gigabit Ethernet Switch or Repeater
1000 MBit/s Backbone
IEEE 802.3 Ethernet
5
IEEE 802.3 Ethernet – Summary
Comparison with other High-speed networks
Capabilities
IP
Compatibility
Gigabit Ethernet
Yes
Fast Ethernet
Yes
Ethernet
Packets
Yes
Yes
Handle
Multimedia
Yes
Yes
Quality of
Service
Yes, with RSVP
and/or 8021p
Yes, with RSVP
and/or 8021p
VLANS with
802,1q / 802.1p
Yes
Yes
ATM
Requires RFC 1557 or IP
over LANE today, I-PNNI
and/or MPOA in the future
Requires LANE
Yes, but application
needs substantial
changes
Yes with SVCs or RSVP
with complex mapping
from IETF (work in
progress)
Requires mapping LANE
and/or SVCs to 802.1q
FDDI
Yes
Yes, though
802.1h translation
bridge
Yes
Yes, with RSVP
and/or 8021p
Yes
IEEE 802.3 Ethernet
6
Fiber Channel
•
ANSI X3T9.3 standardized it in 1995 (started in 1988)
– Designed to transport many protocols, such as FDDI, serial HIPPI,
SCSI, Gigabit Ethernet, IP and others
– Switched full duplex medium
– Channels are established between the Originator and the Responder
– Transfer rates from 100 Mbit/s to 3.2 Gbit/s
– Distance up to 10 km (for single mode fiber)
– Multi-layered stack of functional levels (not mapping directly to OSI)
– Different topologies can be configured
• point-to-point
• arbitrated loop
• switched fabric
IEEE 802.3 Ethernet
6
Fiber Channel (cont.)
•
•
•
•
Lower two layers (FC-0 and FC-1) (almost) correspond to the
1000-Base-X PHY layer
Ethernet requires a lower laser linewidth and has a different data rate
Most common data rate is 100MByte/s=800Mbit/s=1063Mbaud
Up to 1063Mbaud copper (STP) can be used as well
CHANNELS
FC-4
IPI
NETWORKS
HIPPI SCSI SBCCS
IEEE 802.2
FC-3
Common Services
FC-2
Framing Protocol / Flow Control
FC-1
FC-0
IP
ATM
1000 Base-X
Gigabit Ethernet
Encode / Decode
133 Mbaud 266 Mbaud
531 Mbaud
1.06Gbaud
2.1 Mbaud
4.2 Mbaud
IEEE 802.3 Ethernet
6
Fiber Channel - Layers
•
FC-0
– Specifies the physical link
• Media, transmitters, receivers, connectors
– Wide range of different technologies supported
• STP, Video cable, 62.5µm and 50µm multimode fiber, single mode fiber
– Open Fiber Control System (OFC)
• Power the laser down if the fiber is open -> eye safety!
•
FC-1
– 8B/10B encoding
• 8 bits of data are encoded in a 10 bit Transmission character
• 4 Transmission characters make up a Transmission word
• Running Disparity (RD) sums up the „1“s and „0“s and can be either
positive or negative
• Depending on the RD value, one of two possible Transmission
characters is chosen for each data byte to achieve a DC free code
• A special character marks the start of Ordered Sets (control sequences)
– Start of Frame (SOF), End of Frame (EOF), Link Reset (LR), ...
IEEE 802.3 Ethernet
6
Fiber Channel - Layers
•
FC-2
– Signalling protocol level
– Defines frame structure
– 32-bit CRC
Start of
Frame
Frame
Header
Optional
Header
4
24
24
Payload
0-2048
CRC
End of
Frame
4
4
Size in bytes
– Different Service classes:
• Class 1
– Circuit switched connection
• Class 2
– Frame switched, connectionless
– ACK confirms the delivery of every frame
• Class 3
– Frame switched, unconfirmed
• Class 4 (fractional bandwidth) to 6 (Multicast) are largely undefined
IEEE 802.3 Ethernet
6
Fiber Channel – Layers (cont.)
Sequences and Exchanges
• Sequence = Group of frames flowing in the same direction
• Exchange = Group of sequences for a single operation
• Protocol = 5 types of exchanges (N_Port Login, Fabric Login, N_Port
Logout, Data transfer, Primitive Sequence)
INITIATOR
RESPONDER
Command Sequence
Acks
Transfer Ready
Data Sequence
Response Sequence
IEEE 802.3 Ethernet
6
Fiber Channel – Layers (cont.)
•
FC-3
– Services for multiple ports on one node
• Striping of hard disks
• Hunt groups (more than port responds to the same alias address)
•
FC-4
– Defines application interfaces to Upper Layer Protocols (ULPs)
•
•
•
•
•
SCSI (Small Computer System Interface)
HIPPI (High Performance Parallel Interface)
IP (Internet Protocol)
AAL5 (ATM Adaption Layer)
IEEE 802.2
IEEE 802.3 Ethernet
6
Fiber Channel – Topologies
•
•
Point-to-point
– Consists of two FC devices connected
– Full bandwidth all the time
Arbitrated Loop
– Up to 127 ports in a single network
– When a node wants to send, it has to gain control of the loop (ring)
•
•
•
•
Send out ARBx Signal with x= physical address of the node
Once it receives its ARBx back, it is allowed to send OPEN Signal (OPN)
Establishes point-to-point communication
All other nodes simply repeat the data
– When more than one node want to send
• Block the ARBy when y is higher than own x
• Otherwise forward ARBy
– Fairness algorithm prohibits a device from
arbitrating again until others had the chance to arbitrate
IEEE 802.3 Ethernet
6
Fiber Channel – Topologies (cont.)
•
Fabric
– Connects up to 224 devices in a cross-point switched configuration
– Provide parallel transmission
– Originator gets a busy signal if not delivered
– Relieve nodes from routing issues
• Either set up a connection (for Class 1)
• Or put responders address on the frame (Class 2)
– Connect devices that run at different speeds
– Provide cable matching
IEEE 802.3 Ethernet
6
Fiber Channel – Summary
•
•
Fiber Channel provides
– 800 Mbit/s over 10s of km between millions of users
– Support for various transmission media
– Point-to-point, loop, switched fabrics
– From 100Mbit/s to 3.2 Gbit/s
– SCSI, HIPPI, LAN card replacement
Fiber Channel drawbacks
– Jungle of standards (over 20 different standards)
– No real shared medium
IEEE 802.3 Ethernet
6
IEEE 802.3 Ethernet – Acronyms
AUI
BNC
CD
CRC
CSMA
DIX
DTE
FLP
FOIRL
GMMI
HSSG
LLC
MAC
MDI
MAU
MII
NRZ
NRZI
Attachment Unit Interface
Baby N Connector
Carrier Detection
Cyclic Redundancy Check
Carrier Sense Multiple Access
DEC, Intel, Xerox
Data Terminal Equipment
Fast Link Pulses
Fibre Optic Inter-Repeater Link
Gigabit Media Independent Interface
Higher Speed Study Group
Logical Link Control
Medium Access Control
Medium Dependent Interface
Medium Attachment Unit
Medium Independent Interface
Non-Return to Zero
Non-Return to Zero Inverted
PAD
PAR
PCS
PMA
PLS
SAP
VG
Packet Assembler / Disassembler
Project Authorisation Request
Physical Coding Sub-Layer
Physical Medium Attachment
Physical Signalling Sub-layer
Service Access Point
Voice Graded
IEEE 802.3 Ethernet
7
IEEE 802.3 Ethernet – References
Antol Badach, Olaf Knauer, Erwin Hoffmann: High Speed Networks,
Addison Wesley, Reading, Massachusetts, 2. Auflage 1997
ISBN: 3-8273-1232-9
Andrew S. Tanenbaum: Computer Networks, Prentice Hall International,
Third Edition, 1996
ISBN: 0-13-394248-1
David G. Cunningham, William G. Lane: Gigabit Ethernet Networking
Macmillan Technical Publishing, USA, 1999
ISBN: 1-57870-062-0
Switched Ethernet
http://jmazza.shillsdata.com/tech/ethernet/switched
Ethernet and Fast Ethernet Guide
http://www.ots.utexas.edu/ethernet
100Base-T Migration Guide
http://www.3com.com/nsc/100208.html
IEEE 802.3 Ethernet
7
IEEE 802.3 Ethernet – References (cont.)
Desktop ATM vs. Fast Ethernet
http://www.networking.ibm.com/atm/atm25fe.html
Gigabit Ethernet Information (PAR, Drafts)
http://www.ots.utexas.edu:8080/ethernet/descript-gigabit-ieee.html
Gigabit Ethernet Technical Overview
http://www.nbase.com/notes/gigabit.html
Gigabit Ethernet Alliance
http://www.gigabit-ethernet.org
IEEE 802.3 Ethernet
7

IEEE 802.3 Ethernet IEEE 802.3u Fast Ethernet IEEE 802.3z Gigabit

Transcription

Similar documents

RM300E RM400E General Information o26142e2