Application Layer of OSI Model (Layer-7)

Application Layer is the highest layer in seven layer OSI Model. It is responsible for End user Network Applications Management. This is the layer where real traffic data is generated in most of the cases. For example, this could be a web request generated from HTTP protocol or a command from telnet protocol. OSI Model divides the network communication processes into seven layers in order to simplify it. Each layer performs specific functions to support the layers above it. The seven Layer model starts from Physical Layer & goes till Application Layer on the top, as below in figure: Functions/Duties Read More …

Presentation Layer of OSI Model (Layer-6)

Presentation Layer of OSI Model

Presentation Layer is responsible for representation & formatting of data for session Layer in encapsulation process. It is the 6th Layer in the seven layer OSI Model after Session Layer. Presentation layer serves like a translator & takes care that the data is sent in such a way that the receiver will understand the information or data and will be able to use the data. OSI Model divides the network communication processes into seven layers in order to simplify it. Each layer performs specific functions to support the layers above it. This seven Layer model starts from Physical till Application Read More …

Transport Layer of OSI Model (Layer-4)

Transport Layer of OSI Model

Transport Layer is the fourth layer in 7 Layer OSI Model after Network Layer. Similar to Layer-2 and Layer-3, this layer also performs addressing & multiplexing but in different domain through TCP and UDP. OSI Model divides the network communication processes into seven layers in order to simplify it. Each layer performs specific functions to support the layers above it. The seven Layer model starts from Physical till Application Layer & Transport layer is in the middle. The core concept behind Transport layer is the “support of Multitasking”. It allows same computer, browser & internet connection to work on multiple Read More …

Network Layer of OSI Model (Layer-3)

Network Layer of OSI Model

Network Layer is the 3rd layer in 7-Layer OSI Model after Data Link Layer. This is the place where most Routing and network stuff resides. It controls the Logical boundaries of Network. Network Layer controls the operation in networking at routing layer. The main aim of this layer is to deliver packets from source to destination across multiple links or networks. If two computers or host systems are connected on the same link, then there is no need for a network layer. Each layer in OSI Model performs specific functions to support the layers above it. This 7x Layer model Read More …

Physical Layer of OSI Model (Layer-1)

Physical Layer of OSI Model

Physical Layer of OSI Model is the first layer in seven layers for simplification. It is responsible for transmission of data between sending & receiving devices. It also defines the means of transmitting raw bits over the transmission media. Physical layer addresses how the data is carried over the Physical media rather than logical data packets over a physical data link connecting network nodes. Each layer in OSI Model has its own duties & specific functions to perform so that it can support the layers above it. Below figure shows the position of Physical layer in the OSI Model:   Read More …

OSI Model

OSI-Model

“OSI Model (Open Systems Interconnection Model) is a reference tool and a reference model for data communications in networks”. It was the first conceptual model for standardized communication in computer Network systems.   Why do we need OSI Model? We need OSI Model for solution to our multiple problems; few of them are described here. Firstly, it is a vendor neutral model. Before OSI Model, each vendor had to use its own network model to manufacture network equipment. So, one vendor’s equipment & the network was not compatible with another vendor’s equipment. Clients and buyers were forced to buy all Read More …

OSI Model Summary Cheat Sheet – Part1

OSI Model CheatSheet Part1 for Cisco CCNA

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