Several physical communication networks currently available can offer very high bandwidth. At the same time, many potential applications are in need for all that bandwidth. Unfortunately, the communication subsystems used today do not preserve the raw network throughput up to the application level. In this paper, we give an overview of the major current trends and approaches proposed to solve the so-called transport bottleneck problem. We discuss issues related to protocol design and implementation as well as the provision of new features at the transport service interface to accommodate emerging applications.