CHAPTER 1 Introduction

1
CHAPTER 1 Introduction

• Yoshiaki Harada

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Introduction

• Contents
• Organizing with Layers and Hierarchies
• The IP-Based Internet
• Communication Services
• Network addressing

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Organizing with Layers and Hierarchies(1/5)

• Layer
• Layering works by dividing all the functions of a
  network into groups and assigning those groups to
  protocol layers.
• Each protocol layer assumes responsibility for
  its own part of the entire networks total
  functionbility,and when all layers operate
  together,they create a complete, functioning
  network.

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Organizing with Layers and Hierarchies(2/5)
compact disc
display package
jewel box
shipping carton
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Organizing with Layers and Hierarchies(3/5)
file data
Computer
name
file data
name
reliability
file data
forwarding
reliability
name
file data
Ethernet
forwarding
reliability
name

file data
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Organizing with Layers and Hierarchies(4/5)

• Hierarchy
• Like layers, hierarchies are another abstract
  concept that helps organize computer networks.
• Hierarchies organize information and delegate
  responsibility

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Organizing with Layers and Hierarchies(5/5)
8901
0956-33-8901
33
0956
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The IP-Based Internet(1/5)

• This figure presets an picture of how a
  networked computer organizes its protocols

Application
Transport
Internetwork
Network Technology
Ethernet
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The IP-Based Internet(2/5)

• Application
• The protocols that actually organize the
  information the networks transfer.
• Transport
• Transport layer protocols take the applications
  information and deliver it to the destination.

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The IP-Based Internet(3/5)

• Internetwork
• internetwork makes sure that information travels
  through networks appropriately and reaches its
  destination, a process known as forwarding.
• Network technology
• systems connect to each other and actually
  exchange information.

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The IP-Based Internet(4/5)

• Host
• systems that primarily send or receive message.
• Router
• systems that relay message across networks.

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The IP-Based Internet(5/5)
Router
Router
Host
Host
Application
Application
Transport
Transport
Internetwork
Internetwork
Internetwork
Internetwork
Ethernet
Ethernet
Dial-up
Ethernet
Dial-up
Ethernet
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Communication Services(1/5)

• Connectionless Delivery
• When a protocol provides this service,it treats
  every message independently.
• The protocol itself requires no interaction
  before accepting a message,nor does it provide a
  context for different messages in a conversation.

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Communication Services(2/5)
1.Request
2.Response
Connectionless delivery
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Communication Services(3/5)

• Connection-Oriented Delivery
• Connection-Oriented protocols that provide
  service usually exchange their own message before
  transmitting actual data
• These preliminary messages establish the
  connection

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Communication Services(4/5)
1.Request
2.Resonse
Connection-Oriented delivery
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Communication Services(5/5)
ATM Network
Application
Application
?
Transport
Transport
?
?
?
?
Internetwork
Internetwork
?
?
?
?
?
?
ATM
ATM
?
?
Combining services
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Network Addressing(1/5)

• Unicast address
• They refer to a single interface.
• Multicast address
• They identify sets of interfaces.
• Broadcast address
• They identify to all interfaces on the network,
  rather than a set of interface.

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Network Addressing(2/5)
Multicact group
multicast
Broadcast
unicast
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Network Addressing(3/5)

• IP Address
• IP address are 32 bits in size, an that notation
  is known as dotted decimal.
• Each 8-bit byte in the 32-bit address is taken
  separately and expressed as a deciaml number.
• The address itself consists of two parts a
  networkprefix and a host identifier.

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Network Addressing(4/5)
172.16.1.2
172
16
1
2
10101100
00010000
00000001
00000010
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Network Addressing(5/5)
173.12.0.0/16 Network
172.16.0.0/16 Network
172.16.1.2
173.12.1.100
172.16.1.100
172.16.1.2
172.16.1.2
172.16.1.3
172.16.1.4