What is the function of the transport layer in networking?

The transport layer serves a critical role in networking by facilitating communication between processes on different hosts. It is responsible for establishing a logical connection between these processes, ensuring that data is reliably transmitted across the network. This layer manages the segmentation of data, providing error checking and flow control features that help maintain the integrity of the data being sent.

By connecting processes, the transport layer ensures that information can be directed specifically to the intended application on the receiving host. For example, it can differentiate between multiple applications that may be running on the same device and ensure that the data is routed appropriately.

In contrast, the other functions listed do not pertain to the specific responsibilities of the transport layer. The physical establishment of network connections is managed by lower layers, while security features, such as encryption, typically reside in higher layers or at the application level. Monitoring network integrity often falls under the realm of network management and security protocols that operate outside the specific duties of the transport layer.