The present invention relates to a sending device able to send packets in a network comprising at least two stations, the said device comprising means for extracting image pips on the basis of a synchronization signal, initializing an image counter on the basis of the image pips, initializing a counter every “m” zero-crossings of the image counter, the counter being regulated by a clock produced by the image counter, sampling the counter every period Tsmp, where Tsmp emanates from a time base synchronized on all the stations of the said network; and sending packets containing the samples of the counter in the network. According to the invention, it comprises means for receiving packets containing samples sent by a station of the network as echo to the samples and when samples are received for: evaluating a duration of propagation of samples over an outward-return trip between the said device and the said station; determining a phase shift value Δφ on the basis of the duration of propagation; sending the phase shift value Δφ in the network.