A Scalable CAC Technique to Provide QoS Guarantees in a Cascade of IP Routers

In this paper, we propose a solution to provide deterministic quality of service (QoS) guarantees in Differentiated Services (DiffServ) framework. We define packet classification functions and traffic conditioning functions, with particular emphasis on shaping functions at edge routers. Our proposal is based on aggregated classification states, within core routers. The original aspect of our contribution is the introduction of a connection admission control (CAC) procedure on the selected paths, in order to provide performance guarantees to traffic aggregates. Another key aspect is the low involvement of core routers in traffic management, obtained by pushing complexity and processing load towards the boundary of the DiffServ domain. We analyze which guarantees can be provided to flow aggregates in these conditions. To this end, we make use of network calculus for deriving bounds on delay and losses within each network node