Service Guarantees for the LBR Class of Service Disciplines

We define a class of rate-based service disciplines called Lower-Bounded Rate (LBR) that provides upper bounds on end-to-end delay, end-to-end delay probability distribution, per-server buffer space requirements, and the probability distribution of per-server buffer space. This class includes VirtualClock, PGPS, and Leave-in-Time. We prove these upper bounds, and we also prove that for an important subset of the LBR class, in the case of a single server, the proved upper bound on delay is the least upper bound. We show that a session does not need to specify its traffic behavior to a network composed of LBR servers, since LBR service disciplines allow calculation of the proved service guarantees as a function of solely a session’s own dynamic traffic behavior. We also show that for a session conforming to a leaky bucket filter, the session’s traffic that exits its network connection is also leaky bucket constrained.