The layers 4-7 of ISO-OSI reference model communicate with peer entities in the end systems. There is no communication with entities in the intermediate systems. In this sense, layers 4-7 are often called end-to-end layers. These are Transport layer, Session layer, Presentation layer and Application layer respectively.
Transport Layer: The transport layer controls and ensures the end-to-end integrity of the data message propagated through the network between two devices, which provides for the reliable, transparent transfer of data between two end points . Transport layer responsibilities include message routing, segmenting, error recovery, and two types of basic services to an upper-layer protocol: connectionless oriented and connectionless. The transport layer is the highest layer in the OSI hierarchy in terms of communications and may provide data tracking, connection flow control, sequencing of data, error checking, and application addressing and identification.