Presented by
Anurag Dixit

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What Is Ethernet?
 A local-area network (LAN) protocol developed by Xerox Corporation in cooperation with DEC and Intel in 1976
 Ethernet uses a bus or star topology and supports data transfer rates of 10/100/1000 Mbps
 The Ethernet specification served as the basis for the IEEE 802.3 standard, which specifies the physical and lower software layers
 Ethernet uses the CSMA/CD access method to handle simultaneous demands
 Ethernet defines the lower two layers of the OSI Reference Model
Technology
 There are two Media Access Control(MAC) protocols defined for Ethernet:– Half-Duplex and Full-Duplex
 Half-Duplex is the traditional form of Ethernet that uses the CSMA/CD protocol
 Full-Duplex bypasses the CSMA/CD protocol
 Full-duplex mode allows two stations to simultaneously exchange data over a point to point page link that provides independent transmit and receive paths
CSMA/CD Flow
 Open Systems Interconnect (OSI) Reference Model -
OSI Model
The Open Systems Interconnect (OSI) reference model outlines 7 layers for an ideal network architecture.
Physical Layer-
– The nuts and bolts layer, where the cable, connector and
signaling specifications are defined
– Describes the electrical, mechanical, and functional interface to the carrier
– It includes:
• Voltages and pulse coding of bits
• Media and media interface
• Line discipline (full or half duplex)
• Pin Assignments
Data Link Layer
– Gets data packets on and off the wire
– Does error detection and correction and retransmission
– The primary purpose of the Data Link Layer is to provide error free transmission of information between two end stations
– The MAC (Media Access Control) on the lower half, deals with getting the data on and off the wire
– The LLC (Logical Link Control) on the upper half, does the error checking
Network Layer
– The Network Layer controls the operation of the network or sub-network
– Routing and flow control are performed here
– This is the lowest layer of the OSI model that can remain ignorant of the physical network
– The general functions are:
• Addressing messages
• Routing messages
• Controlling congestion
• Translating addresses
• Counting packets
 Transport Layer
– Ensures the performance of the lower 3 layers
– It provides a transparent, logical data stream between the end user and the network service
– This is the lower layer that provides local user services
– It provides the session layer with reliable message transfer facilities
 Session Layer
– Control the communications between applications across a network
– Testing for out-of-sequence packets and handling two-way communication are handled here
 Presentation Layer
– The Presentation Layer formats the data to be presented to the Application Layer
– Differences in data representation are dealt with at this level For example, UNIX-style line endings (CR only) might be converted to MS-DOS style (CRLF), or EBCIDIC to ASCII character sets
– It can be viewed as the translator for the network
– It also does:
• Encryption
• Encoding
• Compression of data
Applications Layer
– Where the user applications software lies
– Handles issues such as:
• File access and transfer
• Virtual terminal emulation
• Inter process communication
• Electronic Mail
• Network Management
 OSI Model (Summary) -
 Ethernet (IEEE - 802.3) Frames -
Ethernet MAC -
 Provides all functions necessary to attach an Ethernet physical layer to the host interface
 Any physical layer chip that supports the MII interface standard can attach to the 10/100 MAC
Ethernet Cabling -
 Twisted Pair Cables
 Coaxial Cables
 Fiber Optic Cables
 Ethernet Connectors -
Interconnection Devices
 Repeater: PHY device that restores data and collision signals: a digital amplifier
 Hub: Multi-port repeater + fault detection
 Bridge: Data page link layer device connecting two or more collision domains. MAC multicasts are propagated throughout “extended LAN.
 Router: Network layer device. IP, IPX, AppleTalk. Does not propagate MAC multicasts.
 Switch: Multi-port bridge with parallel paths
Four Aspects to Home Networking -
Ethernet - A Viable Technology for us
 Ethernet is a proven and mature technology
– Has been used in enterprise networking for years
– Inexpensive standard interface on most computers
 Simple algorithm, inexpensive implementation
– Network Interface Cards, Cables, Hubs, and other equipment are relatively inexpensive
 Handles video applications quickly and effectively
– High quality video applications require bandwidth of greater than 30 Mbps Scalability
– Install/ disconnect stations on the fly without disruption
Summary
 The digital consumer revolution & the Internet are forcing highbandwidth broadband to the home
– Ethernet offers a viable home networking technology
 Various Ethernet-based products are being developed
– Residential gateways: DSL, cable, satellite modem
– Technology bridges: Ethernet-to-1394, HomePNA-to- Ethernet, Ethernet-to-wireless LANs
– Ethernet enabled information appliances: digital TV, DVD player, Internet screen phones, PCs, printers, etc.
 Spartan-II FPGAs, CoolRunner & 9500 CPLDs provide system interconnectivity in Ethernet based products