Marking mechanism for enhanced end-to-end QoS guarantees in multiple DiffServ environment

Recent demands for real time applications have given rise to a need for QoS in the Internet. DiffServ is one of such efforts currently being developed by IETF. In a DiffServ network, previous researchers have proposed several marking mechanisms that are adapted to operate in intra-domain rather than in multi-domain. In this paper, we propose an enhanced marking mechanism based on a color-aware mode using the conventional tswTCM for flows crossing one or more DiffServ domains in order to guarantee effectively enhanced end-to-end QoS. The key concept of the mechanism is that the marking is carried out adaptively based on the initial priority information stored at the ingress router of the first DiffServ domain and the average queue length for promotion of packets. By statistics based on simulations, we show that the proposed marking mechanism improves an end-to-end QoS guarantee for most cases.