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2.1.1.2 OSI Reference Model
Open
Systems
Interconnections (OSI)
Reference
model
is
another
standardized
protocol
architecture
that
is
intended
to
present
good
interoperability
between
various
computers or
machines and
for
economical
reason. It
was
ascertained when
the
idea
to
have
manageable and
well-structured communication architecture
in
network arose
and
the
International
Organization
and
Standardization (ISO)
came
to
establish
a
subcommittee to build up the OSI layer architecture [3].
To
efficiently
establish
interconnection
between
computers,
OSI
model
uses
a
hierarchical set of layers. There are seven layers of OSI model:
•
Application
Layer
is
used
for
applications,
such
as
HTTP,
that
are
specifically
written
to
run
over
the
network
and
allows
accesses to
network services that
support
user
application and
handle
network
access,
flow,
and
recovery.
It
also
works
to
handle
some
issues
in
term
of
network
transparency,
resource
allocation,
and
problem
partitioning. Basically, this
layer
is
concerned with
the
user’s view of the network, such as doing formatting or logging in.
•
Presentation
Layer
is
meant
to
support
translation
between
applications
and
network formats. Protocol conversion is taken place in this layer.
•
Session
Layer
is
basically
to
help
establish,
maintain,
and
terminate
session
across the network between cooperating applications.
•
Transport
Layer
is
used
to
maintain
and
manage
the
flow
control
of
transmitted
data between end points or hosts across the network and to handle error recovery.
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