1. The transport layer provides the functional and procedural means of transferring variable-length data sequences from a source to a destination host via one or more networks while maintaining the quality of service functions.

2. The basic function of the transport layer is to accept the data from the session layer, split it up into smaller units, pass these to the network layer, and ensure that the pieces all arrive correctly at the other end.

3. This is done efficiently in a way that isolates the upper layers from the inevitable changes in the hardware technology.

4. The transport layer creates a distinct network connection for each transport connection required by the session layer.

5. The transport layer create multiple network connections, dividing the data among the network connections to improve throughput.