QoS control in ATM networks: a VP-shaper that regenerates quasi CBR-VCs

Abstract

This paper presents a VP-shaper for ATM networks that also converts jittered CBR traffic on the VCs into near CBR traffic. In contrast with conventional VP-shapers, the proposed shaper controls clumping of cells at the VC-level. Its scheduler guarantees the minimum inter-departure time of cells at both the VP and the VC levels. Furthermore, a dynamic priority scheme, where the cell with the earliest inter departure time limit has the highest priority, reduces cell-diffusion at the VC-level. In addition, two QoS levels are defined. Simulations show that compared with a conventional shaper, the delay and CDV performance are very good for high QoS level VCs, even when there is only a small number of low QoS level VCs. The proposed VP-shaper is thus particularly suitable for circuit emulation services. The low-priority VCs support the best effort service class.<>