Dynamic-distributed differentiated service for multimedia applications

Differentiated services (DiffServ) are a set of technologies by which network service providers can offer differing levels of network quality-of-service (QoS) to different customers and their traffic streams. In DiffServ, packets of the same QoS specification are grouped together and forwarded in the same manner, e.g. to a given subnet or set of subnets with some level of service provisioning. Thus, DiffServ scales better than the per-flow integrated service (IntServ). A major disadvantage of DiffServ, in comparison with IntServ, is that DiffServ does not provide a full guarantee to every application flow, especially for multimedia applications. In this paper, we propose the so-called "dynamic-distributed DiffServ" scheme that allows every DiffServ aggregate a fair chance of passing through the router in the same period of time, while guaranteeing an upper bound on the delay time and delay variations for multimedia data packets inside the DiffServ domain. The scheme is attractive in that it is simple and does not involve the maintainance of complicated per-flow state information. The scheme works well for all DiffServ services, including the premier service and the assured-forwarding service.