Protocol Architecture Models
An application protocol is a layer of hardware and software that supports data transfer between systems and applications.
Most network protocol suites are presented as structured in layers, sometimes collectively referred to as a protocol set. Each layer is designed for a specific purpose and present in both sending and receiving hosts.
There are some Standardized Protocol Architectures
*OSI Reference model
*TCP/IP protocol suite
*IBM Systems Network Architecture (SNA)
*DOD Model
Open Systems Interconnection(OSI)
Open Systems Interconnection Basic Reference Model (OSI Reference Model or OSI Model) is an abstract description of the design of layer communication and computer network protocol. It was developed as part of the Open Systems Interconnection (OSI) program. In its basic form, it divides network architecture into seven layers: top-down application, presentation, session, transport, networks, data links, and physical layers. User data is passed from layer to layer. Hence it is often referred to as the OSI Seven Layer Model.
Transmission Control Protocol / Internet Protocol (TCP / IP)
Transmission Control Protocol / Internet Protocol (TCP / IP) is a communication protocol used to connect Internet network devices. It is also used in personal computer networks. TCP / IP defines how data is transmitted over the Internet and provides communications that can identify packet breakage, address, transmission, diversion, and receipt. TCP / IP requires minimal central management and is designed to make networks reliable with the ability to automatically recover from any device failure on the network.
Department of Defense (DOD) Model
The DoD model is a condensed version of the OSI model and only has four layers.
Advantages of Layering
* Describes the work that takes place in each layer of the model that encourages industrial standardization.
* It is the changes that occur in one layer that affect the other layers.
*Dividing the network communication process into smaller sections facilitates software development, design, and troubleshooting.
*Network component standardization allows many vendors to develop.
*They can solve the problem quickly and efficiently by looking at the layers that cause the problem rather than finding the entire network.
*Network layering allows different types of network hardware and software to communicate.