Estimating One-way Delays from Cyclic-Path Delay Measurements

In this paper we present a novel approach for the estimation of one-way delays from cyclic-path delay measurements that does not require any kind of synchronization among the nodes of the network. Furthermore, this approach is taking into account the asymmetric nature of the network, and the fact that traffic flows are not necessarily the same in both directions. Our approach is based on cyclic-path delay measurements, each of which is extracted using a single (source) clock and therefore is accurate. The basic idea of the approach is to express the cyclic-path delays in terms of one-way delay variables. If there were enough independent cyclic-path delay measurements, then one could solve explicitly for the one-way delays. We show that the maximal number of independent measurements that can be taken is smaller, hence a procedure for estimating the one-way delay is proposed. Keywords— Cyclic-path delay; Round-trip delay; One-way delay; Estimation; Measurements