A connectionless approach to providing QoS in IP networks

The attempt to provide QoS in IP networks has raised some interesting questions on how a service can be provided to meet the application requirements while obeying the network resource constraints. Previous efforts focussed on a flow-based, connection oriented approach to deliver QoS for IP Networks - Intserv. This approach was quite comprehensive but it has not been widely deployed because of complexity and scalability issues. A recent packet marking based scheme called Differentiated Services (Diffserv) Architecture provides a relatively simple and coarse approach. It is too early to predict the usefulness of this approach. This paper outlines a framework to deliver DP QoS which is based on Intserv. It addresses scalability concerns by removing the need for a connection-oriented reservation setup mechanism and replaces it with a Diffserv-like mechanism to consistently allocate bandwidth end-to-end in a network. A prototype device is discussed that manages bandwidth on a node. An algorithm is presented that allows the device to automatically detect application QoS requirements without the need for application-level signalling. A priority-based scheduling mechanism with a variant of weighted round-robin is described.