PRESENTING BY: ABHIJEET PRADHAN K.VINOD KUMAR SITANSU DALEI ANUP PATNAIK

CONTENTS LAN ETHERNET TRADITIONAL ETHERNET 1. ETHERNET FRAME FORMAT 2. PREAMBLE FORMAT AND FUNTION 3. FRAME LENGTH 4. ADDRESSING 5. PHYSICAL LAYER 6. CHANGES IN THE STANDARD FAST ETHERNET 1. GOALS OF FAST ETHERNET 2. MAC SUBLAYER 3. AUTO NEGOTIATION 4. TOPOLOGY 5. IMPLEMENTATION & ENCODING

Contd… GIGABIT ETHERNET 1. PHYSICAL LAYER OF GIGABIT 2. RECONCILIATION 3. GMII 4. PHY(TRANSCIEVER) 5. MDI 6. IMPLEMENTATION 7. TWO WIRE IMPLEMENTATION(1000Base-x) 8. 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: 1. Ethernet 2. Token ring 3. Token bus 4. FDDI (Fiber Distributed Data Interface) 5. 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: 1. Traditional Ethernet(10 MBPS) 2. Fast Ethernet(100 MBPS) 3. Gigabit Ethernet(1 GBPS) 4. Ten gigabit(10MBPS)

TRADITIONAL ETHERNET In 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:  Preamble  SFD(Start frame delimiter)  DA(Destination address)  SA(Source address)  Length or type  Data  CRC(Cyclic redundancy check)

Preamble Format The first seven bytes of the preamble are all the same: The last byte, or the Start of Frame byte is slightly different: 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 signal is easy to detect, but a signal might be interpreted as 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= )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: 1. Unicast address(if the bit is 0) 2. Multicast address(if the bit is 1) 3. Broadcast address(if all bits are 1)

Physical layer Traditional Ethernet defines several physical layer implementation. 4 are the most common they are: 1. 10Base5(Thick Ethernet) 2. 10Base2(Thin Ethernet) 3. 10Base-T(Twisted-Pair Ethernet) 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: 1. Bridged Ethernet 2. Switched Ethernet 3. 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 : a. To allow incompatible device to connect to one another b. To allow one device to have multiple capabilities c. 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/ = 25 MHz 3 d. Three signal levels : +V, 0, -V

Cond…. e. Ethernet inter frame gap of 9.6 microseconds becomes 960 nanoseconds in Fast Ethernet. f. 100 m. max distance to hub; 200 meters between stations. g. 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) i. 1000Base –SX(Shortwave optical fibre) ii. 1000Base –LX(Longwave optical fibre) iii. 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 It is mainly used for industrial applications.

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