Unsplittable Anycast Flow Problem: Formulation and Algorithms

Abstract

Our discussion in this article centers on a new optimization problem called unsplittable anycast flow problem (UAFP). We are given a directed network with arc capacities and a set of anycast requests. Anycast is a one-to-one-of-many delivery technique that allows a client to choose a content server of a set of replicated servers. In the context of unsplittable flows, anycast request consists of two connections: upstream (from the client to the server) and the downstream (in the opposite direction). The objective of UAFP is to find a subset of the requests of maximum total demand for which upstream and downstream connection uses only one path and the capacity constraint is satisfied. To our best survey, this is the first study that addresses the UFP (unsplittable flow problem) in the context of anycast flows. After formulation of UAFP, we propose several heuristics to solve that problem. Next, we present results of simulation evaluation of these algorithms.