What is OSI Model | History of OSI Model | OSI Model Explained | Why use OSI Model
Title----What is OSI Model | History of OSI Model | OSI Model Explained | Why use OSI Model
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Why use the OSI model?
When it comes to safety, practitioners must keep a few things in mind. For example, for a stack of networks, OSI (Open System Interconnection) provides the necessary principles for managing both the technical aspects and risks of architecture.
Despite the fact that data security has changed to cloud-first environments, the OSI model remains relevant. The reasons why the OSI model remains relevant are as follows:
Our technology helps detect threats across the stack
This makes it possible to have a data-centric security posture
Enables cloud adoption through a security-first approach
As well as protecting cloud infrastructure
OSI Model
. Stand for open system interconnection.
. in the 1970's the international standard organization(ISO) came forward to standardize network communication.
. the goal was to have a common protocol irrespective of the underlying hardware or manufacturer.
. divides network communication into seven layers.
. it is a purely logical concept, the layer does not directly represent network components.
Physical Layer
. data at this layer is in the form of bits-zeros and ones.
. defines the electrical and physical specifications of hardware used to communicate over the network.
. also define standards for the type of communication:
simples-one way only.
half duplex- two-way, but only send or receive at a time.
full duplex- two-way, send or receive at the same time .
data link layer
. Bits received from the physical layer are transformed into frames.
. is responsible for communication over the LAN or the same network.
. also responsible for physical addressing, also known as the MAC address.
. other functions include flow control and error control.
. the protocol includes Ethernet, frame-relay, token ring, fiber distributed data interface(FDDI).
. the device includes bridges and layer 2 switches.
network layer
. frames received from the data link layer are transformed into packets.
. responsible for logical addressing of devices- this is done using IP address.
. protocol at this layer include ipv4, ipv6, icmp, ipsec etc.
. devices include layer 3 switches, routers firewalls, etc.
transport layer
. packets received from the network layer are transformed into the segment.
. responsible for providing a transport protocol such as TCP and UDP.
. also responsible for process separation.
session layer
. responsible for establishing and controlling sessions between the sender and receiver.
. also responsible for synchronizing the session using the sequence number.
. protocols include NetBIOS, SOCKS, and Network file system(NFS).
presentation layer
responsible for presenting or formatting the data received in generic format from the lower layers into well-known formats.
. for example JPEG, MPEG.
. also responsible for compression and encryption.
application layer
provides the interface between the application and the underlying network.
not the same as the applications used on the computer.
provide the services or protocols that allow applications to communicate with the network stack.