Equipment Description

 

 

 

The following table describes the seven OSI layers (bottom-top):

 

 

 

 

 

 

Number

Layer

Data

Description

 

 

 

 

 

 

Media Layers

 

 

 

 

 

 

 

 

1

Physical layer

Bits

Defines all electrical and physical specifications for the

 

 

Media, Signal, and Binary

 

devices.

 

 

Transmission

 

 

 

 

 

 

 

 

2

Data link layer

Frames

Provides the functional and procedural means to transfer

 

 

MAC and LLC

 

data between network entities and detect and correct

 

 

 

 

 

errors that may occur in the Physical layer.

 

 

 

 

 

 

3

Network layer

Packets

Provides the functional and procedural means of

 

 

Path Determination and IP

 

transferring variable length data sequences from a

 

 

 

 

 

source to a destination via one or more networks.

 

 

 

 

 

 

Host Layers

 

 

 

 

 

 

 

 

4

Transport layer

Segments

Provides transparent transfer of data between end users.

 

 

End-to-End Connections and

 

 

 

 

Reliability

 

 

 

 

 

 

 

 

5

Session layer

Data

Provides the mechanism for managing the dialog

 

 

Interhost Communication

 

between end-user application processes.

 

 

 

 

 

 

6

Presentation layer

Data

Relieves the Application layer of concern regarding

 

 

Data Representation and

 

syntactical differences in data representation within the

 

 

Encryption

 

end-user systems.

 

 

 

 

 

 

7

Application layer

Data

Interfaces directly to and performs common application

 

 

Network Process to

 

services for the application processes.

 

 

Application

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

33003405 07/2007

55

Page 55
Image 55
Schneider Electric XPSMF2DO801 Following table describes the seven OSI layers bottom-top, Number Layer Data Description