On Flow Distribution over Multiple Paths Based on Traffic Characteristics

Abstract

In traffic engineering to effectively distribute traffic flows over multiple network paths, taking into account traffic characteristics for individual flows is vital in appropriately assigning flows to network paths for achieving better delay performance of the total traffic. All flows assigned to a path, in which some flows are highly bursty, equally experience a significant queuing delay when the path is highly utilized. We analyze the mean, variance, and 99.5^th percentile of queuing delay when two types of flows are multiplexed into a single path using an infinite buffer model with on-off state fluid flows. This is carried out to find a better traffic distribution strategy over multiple paths so as to lower queuing delay incurred to multiplexed flows with distinct traffic characteristics. From the analytical results, we found that trivial strategies, such as dividing individual types of flows in a proportional manner to the bandwidth of each path, or segregating distinct types of flows as much as possible, do not always achieve a good delay performance, e.g., in terms of max-min fairness. Thus, the flows should be distributed considering their traffic characteristics, the number of flows, and the path bandwidths.