© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public 1Version 4.0

OSI Data Link Layer

Network Fundamentals – Chapter 7

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OSI Reference Model

Layer 2

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What will we learn from chapter 7?

Their role in data transmission Prepare data for transmission on network media Media access control methods Common logical network topologies Encapsulating packets into frames Layer 2 frame structure - generic fields Frame header and trailer fields:

addressing QoS Type of protocol Frame Check Sequence

4© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public

Data Link Layer – Accessing the Media

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Data Link Layer – Accessing the MediaWhy Data Link layer protocols required to control media access

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Data Link Layer – Accessing the Media

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Data Link Layer – Accessing the Media

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Data Link Layer – Accessing the Media

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Media Access Control TechniquesControlling access to the media

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Media Access Control TechniquesTwo media access control methods for shared media and their basic characteristics

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Media Access Control TechniquesFull Duplex and Half Duplex as it relates to Media Access Control for non-

shared media

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Media Access Control Techniques

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Media Access Control Techniques

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Media Access Control Techniques

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Media Access Control Techniques

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Media Access Control Techniques

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Media Access Control Addressing and Framing Data

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Media Access Control Addressing and Framing Data

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Media Access Control Addressing and Framing Data

The role of addressing in the Data Link layer - cases where addresses are needed – or not needed

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Media Access Control Addressing and Framing Data

21© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public

What did I Learn from chapter 7?

Their role in data transmission They prepare data for transmission on network media Media access control methods Common logical network topologies Encapsulating packets into frames Layer 2 frame structure - generic fields Frame header and trailer fields:

addressing QoS Type of protocol Frame Check Sequence

22© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public

Data Link Layer

NextOSI Physical Layer