Technologies are generally described for measuring clock skew between two remote hosts connected through a computer network. According to some examples, pairs of probe packets, also referred to as a compound probe, may be transmitted over an end-to-end path in both directions (forward and reverse paths) to measure a gap value at the end nodes for clock skew estimation. Compound probes may arrive at the end nodes with a zero dispersion gap (no separation) and the gap values along the forward and reverse paths may be determined by a capacity of the links connected to the end nodes added to the clock speeds of the measuring nodes upon arriving at the end nodes. The link capacity is a constant network parameter. Thus, the ratio of the measured gap values may provide an estimate of clock speed discrepancy between the end nodes.