Enhancing end-to-end QoS granularity in DiffServ networks via service vector and explicit endpoint admission control

The DiffServ model is considered as a scalable and viable solution to provide QoS in the Internet. However, the current DiffServ model can only provide a coarse end-to-end QoS granularity to individual data flows. This is undesirable for many network services such as the virtual private network (VPN), since it may result in low resource utilisation to guarantee the required QoS. In the paper the concept of service vector is proposed to provide finer QoS granularity in DiffServ networks through the framework of a distributed admission control scheme referred to as explicit endpoint admission control (EEAC). Specifically, by applying the proposed service vector and EEAC scheme, a data flow is allowed to choose different services at different nodes to achieve fine QoS granularity and architectural scalability. The models and solutions that represent the users´ behaviour in selecting the appropriate network services are also discussed. The performance evaluation of the proposed approach demonstrates that the service vector and EEAC scheme can result in lower request drop ratio, satisfactory end-to-end performance, fine end-to-end QoS granularity, and lower cost for each user.