- We present a novel approach for the estimation of one-way delays between network nodes without any time synchronization in the network. It is based on conducting multiple and simple one-way measurements among pairs of nodes, and estimating the one-way delays by optimizing the value of a global objective function that is affected by the overall network topology and not just by individual measurements. We examine two objective functions. The first intuitive choice is the least square error (LSE). Using a novel concept of delay-induced link probabilities, we develop a second objective function that is based on the maximum- entropy (ME) principle. Extensive numerical experiments show that both functions considerably outperform the common method of halving the round-trip delays. They also show that ME outperforms the commonly used LSE.