OSI Model Data Link Layer | Computer Networks Tutorial | Minigranth
Data Link Layer : OSI
Model
Data Link Layer is
the second layer from bottom of the OSI
Model and it is responsible for successful data
synchronization.
It means Data Link
Layer provides or acts as an intermediate, ensuring delivery of data message
to its respective destination in the network by using the physical address
of the device known as MAC (Media Access Control) Address.
This layer
translates the data received in the form of bits from physical layer into
respective format and forwards it to network layer.
Also, Data-Link
Layer assembles the data message into data frames. These data frames are
special structures(like letter which contains sender address and receiver
address) containing the source address field, destination address fields and
the data message.
Data Link Layer is
sub divided into two fields known as:
Logical Link
Control.
Media Access
Control.
Data Link Layer : Header Format
Logical Link Control
is responsible for establishing and maintaining communication links between
the devices whereas Media Access Control maintains the physical address of
sender’s and receiver’s device for proper reliable delivery of data
packets.
Data Link Layer :
Functions & Features
The most basic
function of Data Link Layer is to synchronize data and ensure proper
delivery of data message from sender to receiver device.
Access control is
feature of Data Link Layer which is responsible for deciding the control
& functioning of device at particular interval of time over a network
consistently of multiple device.
Distortion,
Un-delivery of data packets and noise in data packets results in error and
this is prevented using Data Link Layer and this feature is called Error Control.
Even before sending
the data packets to receiver, adding sender’s & receiver’s address to
the frame for reliable data delivery known as physical address(MAC Address) is done using features of
physical addressing.
Framing & Flow
control are other features of the Data-Link Layer where Framing is
responsible for generating data frames & Flow Control ensures that speed
of data transmission by sender and data absorption by receiver are balanced.
It ensures that faster data transmission and slow data absorption or slow
data transmission and faster data absorption must not occur.