Generalized load sharing for packet-switching networks

Abstract

In this paper, we propose a framework to study how to effectively perform load sharing in multipath communication networks. A generalized load sharing (GLS) model has been developed to conceptualize how traffic is split ideally on a set of active paths. A simple traffic splitting algorithm, called weighted fair routing (WFR), has been developed at two different granularity level, namely, the packet level, and the call level, to approximate GLS with the given routing weight vector. The packet-by-packet WFR (PWFR) mimics GLS by transmitting each packet as a whole, whereas the call-by-call WFR (CWFR) imitates GLS so that all packets belonging to a single flow are sent on the same path. We have developed some performance bounds for PWFR and found that PWFR is a deterministically fair traffic splitting algorithm. This attractive property is useful in the provision of service with guaranteed performance when multiple paths can be used simultaneously to transmit packets which belong to the same flow. Our simulation studies, based on a collection of Internet backbone traces, reveal that WFR outperforms two other traffic splitting algorithms, namely, generalized round robin routing (GRR), and probabilistic routing (PRR). These promising results form a basis for designing future adaptive constraint-based multipath routing protocols.