This invention relates to packet selection techniques that can be used in conjunction with a clock recovery mechanism to mitigate the effects of packet delay variation on timing messages exchanged over a packet network, particularly when seeking to synchronize the time of a clock in a slave device to that of a master clock. The packet selection techniques can assist in reducing the noise in the recovered clock signal at the slave device, allowing recovery to a higher quality. Embodiments of the invention provide techniques based on extracting timing packets that create a constant interval between the arrival of selected packets at the slave device and on extracting timing packets which are closest to making the interval between arrival of the selected packets equal to the interval between the departure of the packets.