NETWORKING MODEL
OSI Model
o OSI stands for Open System Interconnection is a reference model that describes
how information from a software application in one computer moves through a
physical medium to the software application in another computer.
o OSI consists of seven layers, and each layer performs a particular network function.
o OSI model was developed by the International Organization for Standardization
(ISO) in 1984, and it is now considered as an architectural model for the inter-
computer communications.
o OSI model divides the whole task into seven smaller and manageable tasks. Each
layer is assigned a particular task.
o Each layer is self-contained, so that task assigned to each layer can be performed
independently.
Characteristics of OSI Model:
o The OSI model is divided into two layers: upper layers and lower layers.
o The upper layer of the OSI model mainly deals with the application related issues,
and they are implemented only in the software. The application layer is closest to the
end user. Both the end user and the application layer interact with the software
applications. An upper layer refers to the layer just above another layer.
o The lower layer of the OSI model deals with the data transport issues. The data link
layer and the physical layer are implemented in hardware and software. The physical
, layer is the lowest layer of the OSI model and is closest to the physical medium. The
physical layer is mainly responsible for placing the information on the physical
medium.
Functions of the OSI Layers
Physical layer
o The main functionality of the physical layer is to transmit the individual bits from one
node to another node.
o It is the lowest layer of the OSI model.
o It establishes, maintains and deactivates the physical connection.
o It specifies the mechanical, electrical and procedural network interface specifications.
Functions of a Physical layer:
o Line Configuration: It defines the way how two or more devices can be connected
physically.
OSI Model
o OSI stands for Open System Interconnection is a reference model that describes
how information from a software application in one computer moves through a
physical medium to the software application in another computer.
o OSI consists of seven layers, and each layer performs a particular network function.
o OSI model was developed by the International Organization for Standardization
(ISO) in 1984, and it is now considered as an architectural model for the inter-
computer communications.
o OSI model divides the whole task into seven smaller and manageable tasks. Each
layer is assigned a particular task.
o Each layer is self-contained, so that task assigned to each layer can be performed
independently.
Characteristics of OSI Model:
o The OSI model is divided into two layers: upper layers and lower layers.
o The upper layer of the OSI model mainly deals with the application related issues,
and they are implemented only in the software. The application layer is closest to the
end user. Both the end user and the application layer interact with the software
applications. An upper layer refers to the layer just above another layer.
o The lower layer of the OSI model deals with the data transport issues. The data link
layer and the physical layer are implemented in hardware and software. The physical
, layer is the lowest layer of the OSI model and is closest to the physical medium. The
physical layer is mainly responsible for placing the information on the physical
medium.
Functions of the OSI Layers
Physical layer
o The main functionality of the physical layer is to transmit the individual bits from one
node to another node.
o It is the lowest layer of the OSI model.
o It establishes, maintains and deactivates the physical connection.
o It specifies the mechanical, electrical and procedural network interface specifications.
Functions of a Physical layer:
o Line Configuration: It defines the way how two or more devices can be connected
physically.
