The OSI (Open Systems Interconnection) model is a framework that defines standards for how data is transmitted and received over a network. It is developed by the International Organization for Standardization (ISO) which divides network communication into several layers. These layers are Physical, Data Link, Network, Transport, Session, Presentation and Application. Each layer has specific functions and it interacts only with the layers directly above and below it.
The OSI model helps different network devices and systems, without their underlying architecture or manufacturer. As every layer works differently, the transport layer, which is the fourth layer of the OSI model, is responsible for end-to-end communication and error recovery between devices in a network. The transport layer of the OSI model has its specific function, the primary function of which is to provide transparent data transfer. The transfer of data is between end systems and to ensure that data arrives in the same sequence without any errors. The transport layer maintains, establishes and terminates logical connections between communicating devices.
The transport layer focuses on process-to-process communication, which ensures that data is delivered to the correct application on the destination device. While other lower layers, such as Data Link layers, deal with physical transmission and routing. Another responsibility of this OSI layer ( Transport layer) is the detection of errors and recovery. During transmission, data packets can be duplicated, get lost or arrive out of order due to network congestion or failure. It is also responsible for flow control and segmentation.
