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

The layer of the OSI model that is responsible for end-to-end communication is the Transport layer. This layer ensures that data is transferred reliably and in the correct sequence between the source and destination hosts. It provides services such as flow control, error detection, and correction. By facilitating these processes, the Transport layer encapsulates data into segments and adds necessary headers that include sequencing and acknowledgment information.

This layer is crucial for maintaining the integrity and reliability of data transmissions over a network, enabling communication sessions between devices regardless of the underlying network infrastructure. It ensures that messages are delivered without errors and in the right order, which is key for applications that require reliable data transfer, such as web browsing or file transfers.

When considering other layers, the Network layer handles packet forwarding and routing based on IP addresses, but does not guarantee end-to-end communication reliability. The Session layer manages sessions between applications, but it does not handle the details of the actual data transport. The Application layer is where end-user software operates but is higher up in the model, focusing on the interface and interaction with the network rather than the underlying transport mechanisms. Therefore, the Transport layer distinctly fulfills the role of managing end-to-end communication in the OSI framework.