Slide 1

LAN ETHERNET(TRADITIONAL, FAST, GIGABIT, TOKEN BUS,TOKEN RING)PRESENTING BY:

ABHIJEET PRADHANK.VINOD KUMARSITANSU DALEIANUP PATNAIK

CONTENTSLANETHERNETTRADITIONAL ETHERNET

ETHERNET FRAME FORMATPREAMBLE FORMAT AND FUNTIONFRAME LENGTHADDRESSINGPHYSICAL LAYERCHANGES IN THE STANDARD

FAST ETHERNET

GOALS OF FAST ETHERNET MAC SUBLAYER AUTO NEGOTIATION TOPOLOGY IMPLEMENTATION & ENCODING

ContdGIGABIT ETHERNET PHYSICAL LAYER OF GIGABITRECONCILIATIONGMIIPHY(TRANSCIEVER)MDIIMPLEMENTATIONTWO WIRE IMPLEMENTATION(1000Base-x)FOUR WIRE (1000Base-T)

TOKEN RINGTOKEN 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:

EthernetToken ringToken busFDDI (Fiber Distributed Data Interface)ATM LAN ETHERNETEthernet was created in 1976 at XEROXS 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 ETHERNETIn traditional Ethernet, the MAC sublayer governs 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:

PreambleSFD(Start frame delimiter)DA(Destination address)SA(Source address)Length or typeDataCRC(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 FUNCTIONPreamble 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:4bLeast 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 layerTraditional 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.

TAP10Base2(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.

TEE10Base-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 EthernetSwitched EthernetFull-Duplex EthernetFAST ETHERNETDesigned to compete with LAN protocols such as FDDI (Fiber Distributed Data Interface) or fiber channelsIEEE (Institute of Electrical and Electronics Engineers) created Fast Ethernet under the name 802.3uGOALS OF FAST ETHERNETUpgrade the data rate to 100 mbpsMake it compatible with Standard EthernetKeep the same 48 bit addressKeep the same frame formatKeep the same minimum and maximum frame length

MAC SUBLAYERThe 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.AUTONEGOTIATIONNew 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 anotherTo allow one device to have multiple capabilitiesTo allow a station to check a hubs capabilityTOPOLOGYDesigned to connect two or more stations together If two stations it can be connected in Point-to-PointThree or more stations need to connected in star topology with the help of a hub or a switch

IMPLEMENTATION AND ENCODINGEither two wire or four wireTwo wire 5UTP(Unshielded Twisted Pair)-(100Base-TX) (100Base-FX)Fiber OpticsFour wire-3UTP(Unshielded Twisted Pair)-(100Base-T4)

ENCODING100Base-TXUses 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 UTPb. Three-level ternary code is used 8B/6T.c. The signaling rate becomes100 x 6/8 ------------ = 25 MHz 3d. 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 ETHERNET1 gigabit=1000mbpsNeed for an high data rate Change in MAC layerTwo distinctive approach. 1. half duplex or with CSMA/CD 2.full duplex of without CSMA /CDImplementation follows the full duplex.Designed to connect two or more stations. PHYSICAL LAYER OF GIGABITConsist of 4 sublayers 1.Reconsilation 2.GMII(Gigabit Medium Independent Interface) 3.PHY(Physical Layout Entity) 4.MDI(Medium dependent interface)

RECONCILIATIONIt sends the 8 bit parallel data

GMIIDefines the process of transmission fron reconciliation layer to PHY layerPrimarily logical interfaceOperates 1000mbpsNo cable No connector

PHY(Transreciever)It is medium dependentIt encodes and decodes

MDIIt connects transreciever to mediumRj-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(Longwave optical fibre)1000Base CX(Short copper jumped ) Four wire (1000 Base T)TOKEN RINGToken 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 BUSToken busis a network implementing thetoken ringprotocol 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.

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