Which layer of the OSI model is responsible for the end-to-end communication?

The Transport Layer is responsible for end-to-end communication within the OSI model. It ensures that data is successfully sent from the source to the destination across a network, providing reliable or unreliable delivery, as needed. This layer manages error detection and correction, flow control, and segmentation of data into manageable packets.

In addition to providing reliability through protocols like TCP (Transmission Control Protocol), the Transport Layer is essential for establishing, maintaining, and terminating connections, which are critical for seamless data transmission. It also adds headers to the packets that provide crucial information such as the source and destination ports, which are necessary for delivering the data to the correct application.

In contrast, other layers of the OSI model serve different functions. The Physical Layer deals with the physical transmission of data over a medium, while the Data Link Layer is concerned primarily with node-to-node data transfer and error detection in the local network segment. The Network Layer’s main role is to route the data from the source to the destination across intermediate routers and manage addressing. While these layers contribute to data communications, it is the Transport Layer specifically that ensures complete end-to-end communication.