Layers of ISO Model
OSI layers it is a layered
architecture, which defined the network standard given by the ISO and therefore
OSI layers has standardized level of service & type of interaction for
computer exchanging information through a communication network.
ISO: International Standard Organisation
IOS : International Organisation for Standardization
OSI: Open System Interconnects
However, the OSI models separates
computer to computer communication into several protocol layer ‘s and the
highest one is application layer & the lowest is Physical layer.
Advantages
- It divides the N/W communication process into smaller
and simpler components, thus easy to design, develop & trouble shoot.
- It allows multiple vendors development through
standards and therefore it allows different manufactures hardware &
N/W components to communicate.
- Therefore it prevents changes in one layer, affecting
the other layer.
ISO Layers
- APPLICATION
LAYER
- PRESENTATION LAYER
- SESSION
LAYER
- TRANSPORT
LAYER
- NETWORK
LAYER
- DATA
LINK
LAYER
- PHYSICAL
LAYER
NOTE: Different Protocol used in all
layers
1) Application Layer
The application layer is
the 7th layer and it serves as an abstraction layer that
specifies the shared communications protocols and interface methods used by
hosts in a communications network and the application layer abstraction
is used in both of the standard models of computer networking and the OSI model
and this layer is responsible for file, folder, printing ,messaging data and
other application services.
2) Presentation Layer
The presentation layer is the 6th
layer and serves as the data translator for the network and It is also called
the syntax layer and this layer is responsible for data translating and code
formatting and therefore it provides coding & conversion function and the
tasks like data compression, decompression , encryption , decryption , or
associated with this layer and the code conversion are EBCDIC (EXTENDED BINARY
CODE DECIMAL INTENDED CODE) and ASCII (AMERICAN STANDARD CODE FOR
INFORMATION INTERCHANGE).
3) Session Layer
The Session Layer is the 5th layer
and it provides the mechanism for opening, closing and managing a session
between end-user application processes and this layer is responsible for
setting up (or) start , managing & terminating the session therefore it
co-ordinate communication between system and server to organize their
communication.
4) Transport layer
The Transport layer is 4th layer and
this layer is responsible for segmenting and unites them on to the data stream
and therefore it provide end to end data services and can establish logical
connection between the sending host & destination host and they provide
reliable or unreliable delivery performs error correction before transmitting
(It divides the segment).
5) Network Layer
The Network Layer is a 3rd layer and
this layer is responsible for managing N/W devices (Router) and therefore it
tracks the location of devices and determines the best path to develop the
routing information table and the two types of packets are used they are Data
and Root Update.
6) Data Link Layer
The Data Link Layer is the 2nd layer
and this layer is the protocol layer that transfers data between nodes on a
network segment across the physical layer and this layer is responsible for
coding, addressing, transmitting information and framing and therefore it
formats the massage into pieces called as a data frames and such as Switches
& Bridges work in this layer.
7) Physical Layer
The Physical Layer is the 1st layer
and this layer is responsible for sending & receiving the bits (0,1) and
therefore it specifies electrical mechanical & functional requirements for
activating maintaining physical links between systems and it interfaces DTE &
DCE for communication and such as Modem, Hub, Repeater works in this layer.
Also Learn About OSI Layers Protocols
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