Local Area Networks
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Local Area Networks
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Project 802
Ethernet
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ดร. อนันต ผลเพิ่ม
Anan Phonphoem, Ph.D.
anan@cpe.ku.ac.th
http://www.cpe.ku.ac.th/~anan
Computer Engineering Department
Kasetsart University, Bangkok, Thailand
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Traditional Ethernet
Fast Ethernet
Gigabit Ethernet
Token Ring
FDDI
More on Ethernet Frame
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Project 802
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IEEE 802 uses HDLC frame structure
2 sets of functions: LLC & MAC
LLC (IEEE 802.2)
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OSI Model and Project 802
End-user information
Logical address, control info, data
MAC
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Contention Î shared media
Physical address, Sync, flag, flow, error control
LLC: Logical Link Control
MAC: Medium Access Control
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IEEE 802 LAN Std. Family
802
Overview and
Architecture
802.7
Broadband LAN
802.1
Network Management
802.8
Fiber Optic
802.2
Logical Link Control (LLC)
802.9
Isochonous LAN
802.3
CSMA/CD - Ethernet
802.10
Integrated Service
Security
1802.3
Conformance Test
Methodology for IEEE 802.3
802.4
Token Passing Bus
802.5
Token Ring
802.6
Metropolitan Area
Network (MAN) : DQDB
802.11
Wireless LAN
802.12
Demand Priority
802.15
Wireless PAN
802.16
Broadband Wireless
Access (Wireless MAN)
802.17
Resilient Packet Ring
802.18
Radio Regulatory
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IEEE 802 LAN Std. Family
Layer 3-7
802.2
Logical Link Control (LLC)
MAC
802.3
802.4
CSMA/CD Token
Bus
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802.5 802.11
Token Wireless
PHY
Ring
LAN
Layer 2
Data Link
Layer 1
Physical
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1
IEEE 802.2 LLC
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PDU Format
Data link control protocol
Exchange data between end users
across LAN using a 802-based MAC
Independent
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Address
used
by LLC
Network topology
Transmission medium
MAC
PDU: Protocol Data Unit in the LLC level
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PDU Control Field
Same as HDLC
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3 Generations of Ethernet
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IEEE 802.3
Traditional Ethernet
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Baseband
(Digital)
Broadband
(Analog)
10Base5
10Base2
10BaseT
1Base5
100BaseT
• 10Broad36
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Regular Ethernet
MAC: Evolution of CSMA/CD
Station 1 transmits to station 4
Assume low collision
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802.3 MAC Frame
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Minimum – Maximum Length
Preamble + SFD Î Flag in HDLC
Why minimum length is important ?
The correction of the CSMA/CD
(Entire frame send out before the collision is detected!)
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Ethernet Address
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Ethernet Address
Each device has a network interface card (NIC)
Can be called
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MAC Address / Physical Address / Ethernet Address
Each NIC has a 6-byte address
Written in Hexadecimal notation
Unicast Address
00-E0-00-AB-04-50
(for source and Destination)
Broadcast Address
FF-FF-FF-FF-FF-FF
Multicast Address
11-C0-02-D9-12-77
00-E0-00-AB-04-50
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Physical Layer
Physical Layer Signaling (PLS)
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Medium Attachment Unit (MAU)
(Transceiver)
Attachment Unit Interface (AUI)
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Ethernet
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For Baseband:
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Manchester Encoding
For Broadband:
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IEEE 802.3
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Differential PSK
Support up to 100 Mbps
Baseband
(Digital)
Broadband
(Analog)
10Base5
10Base2
10BaseT
10BaseFL
1Base5
100BaseT
• 10Broad36
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Notation
10Base5
Thicknet
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10Base5: Ethernet Segments
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10BASE5
Repeater: not an amplifier Î regenerate
Why 2500 meters?
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Transceiver
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Notation
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10Base2
10Base2
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Notation
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10BaseT
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10BaseT
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10Base-FL
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Notation
1BASE5
•AT&T product
•Seldom used now ??
•Range Î can be cascaded (not all to Hub)
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Network with/without bridge
Switched Ethernet
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Collision Domain
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Area of collision
All Layer 1 connections
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Collision Domain
Cross cable – Point-to-Point
Coaxial cable – Bus
Hub – Star
Repeater – Extended network segment
Is large network connected by
repeaters good?
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Switched Ethernet
Microsegmentation
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Full-Duplex Switched Ethernet
Fast Ethernet
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Medium-independent interface
(MII)
Fast Ethernet
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RS: replaces PLS in the
10Mbps Ethernet
Encoding moves to PHY
Encoding is mediumdependent
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100Base-TX
Fast Ethernet
100Base-T4
100Base-X
4 pairs of UTP
(CAT3)
100Base-TX
2 pairs of UTP(STP)
100Base-FX
2 Optical Fibers
Signaling: NRZ-I
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Encoding in 100Base-TX
100Base-FX
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Encoding in 100Base-FX
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100Base-T4
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100Base-T4
Fast/Gigabit Ethernet
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the speed increases
if collision domain decreases
10Mbps, collision domain Î 2500 m. ??
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Fast Ethernet
Min. Ethernet Frame = 72 bytes (including preamble)
Gigabit Ethernet
10 Mbps
2500 m
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Gigabit Ethernet
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1000Base-X
Encoding in 1000Base-X
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1000Base-T
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Encoding in 1000Base-T
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Token Passing
Token Passing
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Token Passing
Token Passing
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Token Passing
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Token Ring
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Differential Manchester encoding
Support up to 16 Mbps
3 types of frames:
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Data/command
Token
Abort
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Token Ring Frame
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Token Ring
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Token Ring Switch
Token Ring
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MAU
FDDI
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Use 4B/5B encoding then NRZ-I
Support up to 100 Mbps
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FDDI
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FDDI Encoding
4B/5B encoding
Data
Sequence
Encoded
Sequence
0000
11110
0001
01001
0100
01010
1000
10010
NRZ-I
Why 4B/5B?
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Long Stream of zero
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FDDI Layers
FDDI Frames
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FDDI Rings
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FDDI Ring Failure
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FDDI Nodes
More on Ethernet Frame
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Data Flow in a station
Ethernet Frame
Hello
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Application
4
Transport
3
Network
5
Hello
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Hello
345
Hello
00
A0
24
A6
F6
44
00
Destination
A0
24
A6
F6
Data Link
1
Physical
2345
Hello
08
00
Physical Address
Physical Address
Type
(First 6-byte)
(Second 6-byte)
2 Bytes
Ethernet Header
2
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Source
IP
TCP
Header
Header
CRC
4 bytes
Data
T
1001101001011101011
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Regular Ethernet
Regular Ethernet
Station 1 transmits to all (broadcast)
Station 1 transmits to station 4
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4
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Promiscuous
mode
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2
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Assignment #1
Explore your network company
Sniffer (e.g. EtherPeek)
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In your report, it must contains
Network and protocol analyzer
1. Physical topology (floor plan, wiring)
2. Logical topology
3. Devices in use (eg. Switch, router, modem, rack,
etc.)
4. IP addresses (no need to show real names or
real IP addresses)
5. Application uses
6. Explain your network policy
7. Criticize/Suggest for improvement
For network maintenance and trouble
shooting
Capture, monitor, analyze, trouble
shooting
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Assignment #1
Explore your network company
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Group of 2 people
One report for each group in Microsoft
Word format
Report should be sent to me by email
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Email: cs761@iwing.cpe.ku.ac.th
The deadline is December 3, 2004
@Noon time
No late assignment will be graded
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