A Simple Fair Cell Discarding Algorithm on Per-VC Queueing Basis

Abstract

In this paper we propose a simple Fair Cell Discarding (FCD) algorithm with virtual per-VC queueing. The main objective of FCD algorithm is to redistribute the cell losses according to each connection's QoS requirement. In case the buffer is full, the newly arrived cell is not automatically discarded but rather a cell from a sub-queue U which is selected according to a fairness criterion which is defined by connections mean arrival rates and their QoS (Quality of Service) such as CLR (Cell Loss Ratio) requirements. Extensive analytical analysis and simulations have been conducted to evaluate FCD algorithm's property and to validate its effectiveness under various traffic and switch configurations. Our study reveals that a very simple approach like FCD can actually differentiate connections with different traffic characteristics and QoS requirements; and satisfy their specified QoS as long as a minimum amount of resources (bandwidth and total buffer space) is allocated for guaranteeing the aggregate QoS/CLR requirement of all active connections.

Admission control for VoIP calls with heterogeneous codecs

“…First, when admitting a new flow, impact of packet level performance on existing flows can vary due to traffic heterogeneity [4,5,6,7,14,17]. Even though assigned bandwidth can satisfy the aggregate delay and loss objectives in a single FIFO queue, packet level performance of some individual sources in heterogeneous traffic might exceed their loss or delay targets.…”