Quality of service in the Internet: the state-of-the-art and challenges

We present the state-of-the-art in quality of service (QoS) schemes in the Internet that exist today in various network architectures and technologies. We describe the building blocks that are needed in constructing these service classes and highlight the applications that can be supported using these. We also outline and analyze the challenges that are faced in making end-to-end QoS a reality in the Internet