The document discusses Ethernet networks and communication. It covers the evolution of Ethernet from standard Ethernet operating at 10 Mbps to 10 Gigabit Ethernet at 10 Gbps. It describes Ethernet's frame format including fields for preamble, start frame delimiter, destination/source addresses, length/type, data, padding, and CRC. It also discusses Ethernet addressing using MAC addresses and Ethernet's access method of CSMA/CD.

1. Communication
Networks
Ethernet
– IEEE 802.3

2. Overview of Module - 2
• Framing
• What is Framing
• Types of Framing
• Methods for identifying the
boundaries
• Flow Control
• What is flow control
• Types of flow control
• Access Control
• What is access control
• Types of access control
• Ethernet – IEEE 802.3
• Evolution of Ethernet
• Frame Format of Ethernet
• Access Control for Ethernet
• Performance Evaluation of Ethernet
• WLAN – IEEE 802.11
• Architecture
• Bluetooth
• WIFI
• Zigbee
• 6LowPan
• Network Layer Services
• IPv4
• Packet switching
• Network Layer Protocols
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3. In this session:
EVOLUTION FRAME FORMAT
ADDRESSING ACCESS METHOD EFFICIENCY
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4. Ethernet – Evolution
• The Ethernet LAN was developed in the 1970s by Robert Metcalfe
and David Boggs. Since then, it has gone through four generations:
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5. Evolution of Ethernet – Standard Ethernet
• Entry level ethernet.
• Operated at data rate of 10Mbps
• Defined the frame format
• Use 48 bit addressing
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6. Evolution of Ethernet – 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.
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7. Evolution of Ethernet – Gigabit Ethernet
• Upgrade the data rate to 1 Gbps.
• Make it compatible with Standard or Fast Ethernet.
• Use the same 48-bit address.
• Use the same frame format.
• Keep the same minimum and maximum frame
lengths.
• Support auto negotiation as defined in Fast Ethernet.
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8. Evolution of Ethernet – 10 Gigabit Ethernet
• upgrading the data rate to 10 Gbps,
• keeping the same frame size and format,
• allowing the interconnection of LANs, MANs, and WAN
possible.
• This data rate is possible only with fiber-optic technology
at this time.
• The standard defines two types of physical layers: LAN
PHY and WAN PHY.
• The first is designed to support existing LANs; the
second actually defines a WAN with links connected
through SONET OC-192.

9. Fiber optic Ethernet

10. Ethernet Frame Format
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11. PREAMBLE:
• 7 BYTES containing alternate 0’s and 1’s
• This alerts the receiving system about the
incoming frame and helps in synchronization
• This is added at physical layer. Not a part of
frame.
SFD (Start Frame Delimiter):
• This segment is 1 byte long.
• This indicates the start of the frame.
• The last 2 bits (11) alerts the receiver that the
next field is destination address.
Destination Address (DA):
• It is of 6 bytes.
• Contains the physical address of the
destination host or stations.
Source Address (SA):
• It is of 6 bytes.
• Contains the physical address of the Source host
or stations.
Length or Type:
• Used for 2 purpose
• Ethernet (Type) – To define the upper layer
protocol.
• IEEE (Length) – To specify the number of bytes in
the data field.
Data & Padding:
• It can be a minimum size from 46 bytes to
maximum of 1500 bytes.
• It carries data encapsulated from the upper
layer
Cyclic Redundancy Check :
• This field contains Error Detection Information.

12. Ethernet - Addressing
• Already Discussed in previous sections
• Ethernet uses MAC Address. Refer to Physical Addressing topic we
studied already
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13. Ethernet – Access Mechanism - CSMA CD
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14. Efficiency of Standard Ethernet
• The efficiency of the Ethernet is defined as the ratio of the time used by a
station to send data to the time the medium is occupied by this station.
The practical efficiency of standard Ethernet has been measured to be
Efficiency = 1 / (1 + 6.4 * a)
• in which the parameter “a” is the number of frames that can fit on the
medium.
• It can be calculated as a = (propagation delay)/(transmission delay).
• Note that as the value of parameter a decreases, the efficiency increases.
• This means that if the length of the media is shorter or the frame size longer,
the efficiency increases.
• In the ideal case, a = 0 and the efficiency is 1.
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15. Session Summary
Ethernet Concepts
• Evolution of Ethernet
• Standard Ethernet and their variations
• Fast Ethernet and their variations
• Gigabit Ethernet and their variations
• 10 Gigabit Ethernet and their variations
• Frame Format of Ethernet
• Access Control for Ethernet – [CSMA – CD]
• Performance Evaluation of Ethernet

16. References:
• Behrouz A. Forouzan, ―Data communication and Networking, Fifth
Edition, Tata McGraw – Hill, 2013
• Larry L. Peterson, Bruce S. Davie, ―Computer Networks: A Systems
Approach, Fifth Edition, Morgan Kaufmann Publishers, 2011.
• Few online References (Will be Mentioned in the description Section)
Thank You…