Quality of assured service through multiple DiffServ domains

Differentiated service (DiffServ) is a technology which is proposed to provide quality of service (QoS) in the Internet, and it is superior to integrated service (IntServ) technology in respect to the simplicity of its architectures and the scalability of networks. Although various simulation studies and estimations over testbeds have investigated the QoS which is offered via the DiffServ framework, almost all of them were focused on the characteristics in a single DiffServ domain. However, the Internet is actually composed of a large number of AS (assured service) domains, and thus packets are very likely to arrive at their destinations through many different domains. From this viewpoint, we focus on the QoS performance in the model consisting of multiple DiffServ domains, especially we investigate quality of assured service to achieve statistical bandwidth allocation with AF-PHB (assured forwarding per hop behavior). Our simulation results show some throughput characteristics of flows over multiple DiffServ domains, and we also make it clear whether the network configurations and traffic properties have impacts on QoS over multiple DiffServ domains or not.