A Unifying Service Discipline for Providing Rate-Based Guaranteed and Fair Queuing Services Based on the Timed Token Protocol

Multiservice networks face the challenge of managing several traffic classes simultaneously. Service disciplines devised for multiservice networks therefore need to be flexible, i.e., able to provide different types of service, in order to accommodate different traffic classes efficiently. In this paper, we present and analyze an innovative Timed Token Service Discipline (TTSD, which has been given Patent Application No. TO2000A001000) which is able to schedule both rate-guaranteed and best-effort traffic simultaneously at a feasible computational complexity. The service paradigm approximated by TTSD is unveiled by means of a fluid-flow analysis and proven to be different from the well-known Generalized Processor Sharing. We then describe the TTSD properties, deriving minimum rate guarantees and delay bounds for leaky-bucket constrained traffic, both in a single node and in a multinode environment. Furthermore, algorithms for selecting the TTSD parameters in order to achieve a prespecified rate and delay guarantees are proposed