Concurrent multipath routing over bounded paths: Minimizing delay variance

In this paper we consider the problem of minimizing delay variance amongst paths utilized for concurrent multi-path routing. We will assume that we are provided with a polynomial size set of paths. Minimizing the variance in the delay will reduce out-of-sequence packets and hence reduce jitter in the received stream. We assume a network with edge delays as well as edge capacities. The edge delays are modelled using constant, affine (including linear) and queueing delays. We show that the problem is NP-hard (even in the case when polynomial-size paths are given and there is no capacity constraint). We also propose a practical heuristic approach and present experimental results on network topologies mimicking large backbone networks.