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LAN ETHERNET(TRADITIONAL, FAST, GIGABIT, TOKEN BUS, TOKEN RING). PRESENTING BY: ABHIJEET PRADHAN K.VINOD KUMAR SITANSU DALEI ANUP PATNAIK. CONTENTS. LAN ETHERNET TRADITIONAL ETHERNET ETHERNET FRAME FORMAT PREAMBLE FORMAT AND FUNTION FRAME LENGTH ADDRESSING PHYSICAL LAYER
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LAN ETHERNET(TRADITIONAL, FAST, GIGABIT, TOKEN BUS,TOKEN RING) PRESENTING BY: ABHIJEET PRADHAN K.VINOD KUMAR SITANSU DALEI ANUP PATNAIK
CONTENTS • LAN • ETHERNET • TRADITIONAL ETHERNET • ETHERNET FRAME FORMAT • PREAMBLE FORMAT AND FUNTION • FRAME LENGTH • ADDRESSING • PHYSICAL LAYER • CHANGES IN THE STANDARD • FAST ETHERNET • GOALS OF FAST ETHERNET • MAC SUBLAYER • AUTO NEGOTIATION • TOPOLOGY • IMPLEMENTATION & ENCODING
Contd… • GIGABIT ETHERNET • PHYSICAL LAYER OF GIGABIT • RECONCILIATION • GMII • PHY(TRANSCIEVER) • MDI • IMPLEMENTATION • TWO WIRE IMPLEMENTATION(1000Base-x) • FOUR WIRE (1000Base-T) • TOKEN RING • TOKEN BUS
Local Area Network (LAN) • LAN is a computer network. • It is designed for a limited geographic area. (eg: Building or Campus) • For sharing resources. • LAN has several technology such as: • Ethernet • Token ring • Token bus • FDDI (Fiber Distributed Data Interface) • ATM LAN
ETHERNET • Ethernet was created in 1976 at XEROX’S PALO ALTO RESEARCH CENTRE (PARC). • Ethernet is now the dominant technology. • It has gone through 4 generations: • Traditional Ethernet(10 MBPS) • Fast Ethernet(100 MBPS) • Gigabit Ethernet(1 GBPS) • Ten gigabit(10MBPS)
TRADITIONAL ETHERNET • In traditional Ethernet, the MACsublayergoverns the operation of the access method. • It also passes the frames from the upper layer to the physical layer. • Standard Ethernet is also known as Traditional Ethernet. ETHERNET FRAME FORMAT • Ethernet frames contains several field: • Preamble • SFD(Start frame delimiter) • DA(Destination address) • SA(Source address) • Length or type • Data • CRC(Cyclic redundancy check)
Preamble FormatThe first seven bytes of the preamble are all the same: 10101010.The last byte, or the Start of Frame byte is slightly different: 10101011. The 7 bytes of the preamble and the Start of Frame create a pattern of 64 bits. They are not officially counted as part of the Ethernet frame. The frame begins immediately after the Start of Frame, without a gap.
PREAMBLE FUNCTION • Preamble tell station ahead to wake up and pay attention: something important is coming. • Apart from being a "get ready" notification, the preamble also serves as a clock synchronization device. • Bits are represented as an electrical voltage - high or low. • The receiver needs to keep pace with the standard interval. • A 10101010 signal is easy to detect, but a 11111111 signal might be interpreted as 1111111 if the receiver's clock is set too slow. • The preamble demonstrates the pace of arriving data and repeats the 1010 pattern long enough to enable the receiver to set its clock.
Contd… • SFD-The second field (1 byte=10101011)singals the beginning of the frame. • DA-Field is 6 bytes. • SA-Field of 6 bytes. • LENGTH OR TYPE-2 bytes in length. • DATA-It is a field minimum of 46 and a maximum of 1500 bytes. • CRC-It is the last field contains error detection information. It is of 4 bytes.
FRAME LENGTH • Ethernet frame have a minimum length of 512 bits or 64 bytes. • Traditional/Standard defines maximum length of a frame as 1518 bytes. ADDRESSING • Ethernet address is 6 bytes(48 bits),normally written in hexadecimal notation, with a colon between the bytes. Eg: 06:01:02:01:2c:4b • Least significant bit of the first byte defines the type of address. • Addressing can be done in: • Unicast address(if the bit is 0) • Multicast address(if the bit is 1) • Broadcast address(if all bits are 1)
Physical layer • Traditional Ethernet defines several physical layer implementation. 4 are the most common they are: • 10Base5(Thick Ethernet) • 10Base2(Thin Ethernet) • 10Base-T(Twisted-Pair Ethernet) • 10 Base-F(Fibre Ethernet)
10Base5 (Thick Ethernet) • It is a half duplex. • Name derives from the size of the table. • First Ethernet to use bus topology. • External transmitter connected via tap to a thick coaxial cable. TAP
10Base2(Thin Ethernet) • It also uses bus topology. • Cable is thinner and flexible and can be bent. • Thin coaxial is less expensive then thick coaxial. • Length cannot exceed more than 185 m due to high level of attenuation. • Tee connection are more cheaper than taps. TEE
10Base-T(Twisted-Pair Ethernet) • It uses star topology. • Station are connected to a hub via two pairs of twisted cable. • Two pairs creates 2 paths. • Maximum length is 100m to minimize the attenuation. • 10Base-F(Fiber Ethernet) • It uses star topology. • Station are connected to a hub using fiber optic cables.
Changes in the Traditional • It has gone through several changes before moving to the higher data rates: • Bridged Ethernet • Switched Ethernet • Full-Duplex Ethernet
FAST ETHERNET • Designed to compete with LAN protocols such as FDDI (Fiber Distributed Data Interface) or fiber channels • IEEE (Institute of Electrical and Electronics Engineers) created Fast Ethernet under the name 802.3u
GOALS OF FAST ETHERNET • Upgrade the data rate to 100 mbps • Make it compatible with Standard Ethernet • Keep the same 48 bit address • Keep the same frame format • Keep the same minimum and maximum frame length
MAC SUBLAYER • The access method is same (CSMA/CD) for the half duplex approach ; for full duplex Fast Ethernet there is no need of CSMA/CD . • However , the implementation keep CSMA/CD for backward compatibility with Standard Ethernet.
AUTONEGOTIATION • New feature that allows a hub or a station a range of capabilities and also allows two devices to negotiate the mode or data rate of operations. • DESIGNED BECAUSE : • To allow incompatible device to connect to one another • To allow one device to have multiple capabilities • To allow a station to check a hub’s capability
TOPOLOGY • Designed to connect two or more stations together • If two stations it can be connected in Point-to-Point • Three or more stations need to connected in star topology with the help of a hub or a switch
IMPLEMENTATION AND ENCODING • Either two wire or four wire • Two wire – 5UTP(Unshielded Twisted Pair)-(100Base-TX) (100Base-FX)Fiber Optics • Four wire-3UTP(Unshielded Twisted Pair)-(100Base-T4)
ENCODING • 100Base-TX • Uses two pair of twisted pair, one pair for transmission and one pair for reception. • Uses either STP or Cat 5 UTP. • Uses MTL-3 signaling scheme that involves three voltages. • Uses 4B/5B encoding. • There is a guaranteed signal transition at least every two bits.
100Base-FX • Uses two optical fibers, one for transmission and one for reception. • Uses FDDI technology of converting 4B/5B to NRZ-I code group streams into optical signals.
100Base-T4 a. Can use four separate twisted pairs of Cat 3 UTP b. Three-level ternary code is used 8B/6T. c. The signaling rate becomes 100 x 6/8 ------------ = 25 MHz 3 d. Three signal levels : +V, 0, -V
Cond…. • Ethernet inter frame gap of 9.6 microseconds becomes 960 nanoseconds in Fast Ethernet. • 100 m. max distance to hub; 200 meters between stations. • Maximum of two Class II repeaters.
GIGABIT ETHERNET • 1 gigabit=1000mbps • Need for an high data rate • Change in MAC layer • Two distinctive approach. 1. half duplex or with CSMA/CD 2.full duplex of without CSMA /CD • Implementation follows the full duplex. • Designed to connect two or more stations.
PHYSICAL LAYER OF GIGABIT • Consist of 4 sublayers 1.Reconsilation 2.GMII(Gigabit Medium Independent Interface) 3.PHY(Physical Layout Entity) 4.MDI(Medium dependent interface)
RECONCILIATION • It sends the 8 bit parallel data GMII • Defines the process of transmission fron reconciliation layer to PHY layer • Primarily logical interface • Operates 1000mbps • No cable • No connector
PHY(Transreciever) • It is medium dependent • It encodes and decodes MDI • It connects transreciever to medium • Rj-45 and fibre optics for gigabit ethernet
Implementation • Two categories 1.Two wire implementation 2.Four wire implementation Two wire implementation(1000Base-X) • 1000Base –SX(Shortwave optical fibre) • 1000Base –LX(Longwaveoptical fibre) • 1000Base –CX(Short copper jumped ) Four wire (1000 Base –T)
TOKEN RING • Token ring uses ring base topology. • It passes token around the network. • It comes in standard 4 and 16 mbps. • High speed token ring at 100 mbps and 1 gbps. • 100 mbps(IEEE802.5t) and 1gbps(IEEE802.5v). • It comes with a high price tag. • Token ring is passing out of use.
TOKEN BUS • Token bus is a network implementing the token ring protocol over a "virtual ring" on a coaxial cable. • A token is passed around the network nodes and only the node possessing the token may transmit. • If a node doesn't have anything to send, the token is passed on to the next node on the virtual ring. • Token bus was standardized by IEEE standard 802.4. • It is mainly used for industrial applications.