Providing quality of service guarantees using only edge routers

Providing strict bandwidth guarantees to packet flows in the Internet is an inherently challenging task. It requires signaling mechanisms, policing mechanisms, accurate and rapid accounting of network resources and call admission control. We present a novel protocol that provides bandwidth guarantees to Internet packet flows. This protocol, called the edge-assisted quality of service (EQOS) protocol, requires modifications to only a subset of an administrative domain's routers, namely the edge routers on the domain's periphery. Legacy routers within the core of the domain require no modifications. Our protocol maintains a high network utilization by dynamic sharing of bandwidth between the reserved and best effort flows. We present the results of several simulation experiments showing that EQOS is able to provide bandwidth guarantees to competing flows.