Efficient support of delay and rate guarantees in an Internet

In this paper, we investigate some issues related to the efficient provision of end-to-end delay guarantees in the context of the Guaranteed (G) Services framework [16]. First, we consider the impact of reshaping traffic within the network on the end-to-end delay, the end-to-end jitter, as well as per-hop buffer requirements. This leads us to examine a class of traffic disciplines that use reshaping at each hop, namely rate-controlled disciplines. In this case, it is known that it is advantageous to use the Earliest Deadline First (EDF) scheduling policy at the link scheduler ([8]). For this service discipline, we determine the appropriate values of the parameters that have to be exported, as specified in [16]. Subsequently, with the help of an example, we illustrate how the G service traffic will typically underutilize the network, regardless of the scheduling policy used. We then define a Guaranteed Rate (GR) service, that is synergetic with the G service framework and makes use of this unutilized band-width to provide rate guarantees to flows. We outline some of the details of the GR service and explain how it can be supported in conjunction with the G service in an efficient manner.