A two-bit scheme for service differentiation in IP networks

This paper presents possible approaches to traffic and service differentiation in IP networks and interesting simulation results for the proposed two-bit service differentiation scheme, currently there are two major approaches to the introduction of quality of service (QoS) to IP networks, integrated services (IS) with RSVP rely on explicit flow-by-flow reservation of network resources, and Differentiated Services (DS) that make use of a relative traffic differentiation based on priorities. Our work is focused on evaluation of properties of IP networks, which use packet priorities for securing different levels of QoS. Our two-bit scheme for service differentiation allows up to four priority levels. For evaluation purposes we chose four applications with different types of traffic and granted them different priorities. First we simulated the current best-effort scheme and then compared it to our two-bit priority scheme under the same set of conditions. Simulations have uncovered many interesting results and justified the implementation of differentiated services into current best-effort IP networks. We conclude that introduction of even simple priority schemes into best-effort IP network, can significantly improve its performance.