(OSI) Standardization of

prunelimitNetworking and Communications

Oct 23, 2013 (3 years and 7 months ago)

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1.2 Open System Interconnection

(OSI) Standardization of

Communication Protocol

Role of OSI


Interpretation between networks


Problem
-
free data communication

Structure of OSI


OSI has 7 layers in hierarchical structure


Changes of each layers would not affect the other
layers


Simplified communication procedures

1.2 Open System Interconnection

(OSI) Standardization of

Communication Protocol


OSI

is an international standard established
primarily by the
ISO

(International Organization
for Standardization) and
ITU
-
TS


(International Telecommunication Union
-
Telecommunication Standardization Sector)

Telephone Communication has two layers

Protocol

for


Communication

Protocol

for


Telephone

Protocol

for


Communication

Protocol

for


Telephone

Recognize only

Their conversation

Recognize only

Electrical signals

2

1

2

1

Physical Connection

Application Layer

Responsible for user interaction.

Presentation Layer

Convert the input data to Binary bits. e.g. ”01000111”

Session Layer

Establish the session, synchronization of the communication.

Transport Layer

Guarantees data transmission between end
-
to
-
end. Packet Control.

Network Layer

Routing (communication pathway), addressing, packaging

Data link Layer

Responsible for transmitting data across a link.

Physical Layer

Responsible for the electrical, mechanical and timing across the line

Comparison of OSI Reference Model
and Computer

Application

Network
Protocol

NIC

Cable

Function

OSI Reference Model

Windows

Abstraction

Application

Presentation

Session

Transport

Network

Data Link

Physical

layering

Note: Network Protocol: ex. TCP/IP

Application: Outlook Internet Explorer

The Role of the first two layers

Hello!
(Input)

Application Layer

Hello!

7

Presentation Layer

6

100101001

To Lower layer

Hello!
(output)

Application Layer

Hello!

7

Presentation Layer

100101001

6

From Lower layer

Communication

Communication

Interprocess

Interprocess

Transmission Path

Session Layer

From upper layer

To upper layer

Session Layer

5

Session Layer

5

Connection establishment

and release

To Lower layer

From Lower layer

Transmission Path

Transport Layer

From upper layer

To upper layer

Transport Layer

4

Transport Layer

4

Alarm notification

Data resend

To Lower layer

From Lower layer

Transmission Path

Network Layer

From upper layer

Data


Packet Header




3

Data

Data


Removed




3

Data

To upper layer

Packet Routing

Router

Router

Router

From lower layer

From lower layer

Transmission Path

From upper layer


Frame Header


2

Data

PH


Removed


2

Data

PH

To upper layer

Data link

Connection

Data

PH

Data

PH

Router

Router

Router

From lower layer

To lower layer

Transmission Path

Data link Layer

Physical Layer

From upper layer



Signal Conversion


1



Signal Conversion


1

To upper layer

Physical

Conversion

Bit Code

Bit Code

Transmission Path