LAN Standards
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Transcript of LAN Standards
Networking Fundamentals
Lecture 3
Ethernet Protocol
IEEE 802 LAN Standards
Additional LAN Standards
Ethernet Milestones
Developed during the mid- 1970 at Xerox
Palo Alto Research Center (Metcalfe)
Later refinement by DEC, Intel and Xerox
(DIX standard )
Became IEEE 802.3 in 1985
Different frame format between Ethernet and
IEEE 802.3
Ethernet Basics
The basics Ethernet Bus
Ethernet Basics
Collisions
Ethernet Basics Cont.
Medium Access Method
Carrier Sense Multiple Access with Collision
Detection CSMA/CD
Ethernet Frame Transmission
Ethernet Frame Reception
CSMA/CD
Common Types of Ethernet
10Base2 (Thinnet Coax) Ethernet
10BaseT (Twisted-Pair) Ethernet
100BaseT (Twisted-Pair) Ethernet
100BaseFL (Fiber-optic) Ethernet
Ethernet Frame
10BaseT Ethernet
Uses UTP cable
Wired in a Star
Connection to hubs/switches and LAN card is
made with RJ-45 connector
LAN Standards
IEEE 802
802.3 (Ethernet)
802.4 (Token bus)
802.5 (Token ring)
802.11 (Wireless LAN)
ANSI standards
FDDI
IEEE LAN Standards
IEEE: Institute of Electrical and Electronic Engineers
IEEE create standards for computer and communications
IEEE 802 series of standards for LAN technologies
IEEE defined several access methods CSMA/CD
Token passing
Demand priority
Protocol Architecture
Lower layers of OSI model
IEEE 802 reference model
LAN layered protocol architecture Physical (topologies)
Media access control
Logical Link Control
All IEEE 802.x have the same LLC sublayer
MAC sublayer has very close relationship with the characteristics of physical medium and the topology of network
IEEE 802 versus OSI
Layer 7
Layer 6
Layer 5
Layer 4
Layer 3
Data Link
Physical Physical
Logic Link Control
Media Access Control
Upper Layers
Protocols
Scope of IEEE 802 Standards
OSI Reference Model
IEEE 802 Reference Model
IEEE 802
802.1 Architecture and Internet
802.2 Logical Link Control
802.3 Ethernet
802.4 Token Bus
802.11 Wireless
LAN Physical Layer
Data Link Layer
MAC
LLC
802.14 Cable Modem
802 Layers - Physical
Signal encoding/decoding
Preamble generation/removal (for
synchronization)
Bit transmission/reception
Transmission medium and topology
802 Layers – MAC and LLC
OSI layer 2 (Data Link) is divided into two in
802
Logical Link Control (LLC) layer
Medium Access Control (MAC) layer
802 Layers - MAC
Assembly of data into frame with address and
error detection fields (for transmission)
Disassembly of frame (on reception)
Address recognition
Error detection
Govern access to transmission medium
802 Layers - LLC
LLC is the upper sub-layer of the OSI data
link layer.
Interface to higher levels
The LLC is the same for the various physical
media (such as Ethernet, token ring, WLAN).
IEEE 802 Protocols
802.1 specifies general procedures that all
LANs follows and how to interconnect with
higher layers.
802.2 relates to end-to-end logical links:
Logical Link Control LLC
802.3 - 802.14 are responsible for: Medium Access Control
Physical Layer Implementation
IEEE 802.2
Used by all standards in IEEE 802 series
Used by FDDI ( FDDI is not IEEE standard)
Logical Link Control LLC
IEEE 802.3
Ethernet is a predecessor of IEEE802.3
Ethernet don’t comply with 802.2
Wiring standards 10base2 (thin coax)
10base5 (thick coax)
10baseT (UTP)
IEEE 802.3 and Ethernet supports MAC address and same physical layer
Access method CSMA/CD (broadcast)
Create heavy traffic
Topology: Bus
Star
Cable support : UTP, Coax and fiber optic
MAC Address
Unique address
Hardware address
Burned on the NIC by the manufacturer
Used to identify the computer on the network
Use 12 hexadecimal digits (48 bits)
Physical Address. . . . . . . . . : 00-22-68-15-A4-2F
First 24 bits are vendor code
Last 24 bits are interface serial number
IEEE 802.3u Fast Ethernet
Higher speed 100Mbps
Access method CSMA/CD
Wiring standards
100baseTX
100baseT4
100baseFX
Topology: Star
Cable support: UTP and fiber optic
IEEE 802.3z and 802.3ab Gigabit Ethernet Used in network backbone
Data rate 1000Mbps
Access method CSMA/CD
802.3z use copper cable and fiber optic cable
802.3ab use cat5 UTP
Wiring standards
1000baseT (cat5 UTP)
1000baseCX (copper cable)
1000baseSX (fiber optic cable)
1000baseLX (fiber optic cable)
IEEE 802.5 Token Ring Token ring was initially developed by IBM
802.5 standard comply with IBM token ring standard
Access method: Token passing
Token is passed in one direction across the network
Data rates 4 or 16 Mbps
May use star topology using MAU Multi-station access unit
MAU can bypass faulty nodes on the ring
Additional LAN Standards
Other LAN standards NOT included in IEEE
802 project
Apple LocalTalk
Fiber Distributed Data Interface
FDDI
FDDI
ANSI Standard
American National Standards Institute
Access method: Token passing
Use 2 counter-rotating rings for redundancy
FDDI can be classified as MAN
Distance up to 200Km
LAN Access Methods Summary
IEEE802.3
Ethernet
CSMA/CD
IEEE802.11
CSMA/CA
Token Ring
IEEE802.5
FDDI
Token passing
Thank you