Implementing integrated and differentiated services for the Internet with ATM networks: a practical approach

This article reports on design, implementation, and preliminary experimentation of a network architecture that supports quality of service for Internet applications. It gives an overview of the various approaches toward communication networks that support application-specific degrees of QoS. Special emphasis is put on the integrated and differentiated services approaches and on combinations of them. A new architecture is described which aims to bring these concepts closer to practical realization in wide-area networks. The new architecture supports the integrated as well as differentiated services approaches in a smoothly integrated way, and uses the capabilities of an underlying ATM network to realize QoS. The enhancements to the existing network infrastructure are deliberately limited to the integration of a single new type of network element called an edge device. The potential benefits of such an architecture for various stakeholders are explained, and how the new architecture could be introduced smoothly in existing networks by small migration steps, also covering networks based on technologies other than ATM. It is shown that the approach can be scaled up to a very large QoS-aware overlay network for the Internet.