KNOWLEDGE
HUB
network engineering community,
not application engineering
the
community itself. In fact, far too
many companies have little or no
Vo l u m e 3
Issue 10
Vo l u m e 3
Issue 10
KNOWLEDGE
HUB
According to the OSI model, the seven layers of networking are:
application security at all—opting
instead to deploy network security
controls around the application—
essentially perimeter protection.
This may be due, in part, because
APPLICATION This layer specifies how users interact with the data on the network through the form of
interfaces and protocols.
PRESENTATION This layer translates data between the application and the network, performing functions
such as encryption, compression, and string conversion.
SESSION This layer manages the connection between different systems (known as a session).
many vendors and companies design
their security posture around the
Open Standard Interconnection model
(OSI) model. Popularized in the mid-
80’s by the International Standards
Organization (ISO), OSI is conceptual
model to promote interoperability
between computing systems. This
model sets out a construct of standard
network protocols divided into seven
10
layers that still govern how all internal
11
and external networks communicate
and function, including how they are
secured.
TRANSPORT This layer defines the protocols and port numbers that hosts on the network use to
communicate
NETWORK This layer moves data throughout the network by selecting the appropriate route and
forwarding the data.
DATA LINK This layer handles the encoding, decoding, and logical organization of bits
into data packets.
PHYSICAL This layer deals with the transmission of electrical signals across different
physical devices.
The OSI Networking
Model
The
OSI
(Open
Systems
Interconnection) networking model
describes how applications exchange
information
over
a
network
by
separating these communications into
seven different “layers.” While each
layer is independently developed, the
OSI model anticipates that each layer
only communicates with the layer
above and below it as information
passes through the layers.
CISO MAG | November 2019
CISO MAG | November 2019