A network device receives a data packet sourced from a root of a tree-based topology and including a data structure identifying transmitted data packets transmitted by the root; in response to determining one or more absent transmitted data packets based on the data structure, the network device starts a deferred transmission timer requiring the network device to wait a first half of a selected minimum contention interval before attempting transmission to a parent at a randomized position within a second half of the selected minimum contention interval, the selected minimum contention interval based on the distance to the root and at least twice that of the parent; the network device selectively transmits a control message to the parent to request the absent transmitted data packets only if, upon reaching the corresponding randomized position of the deferred transmission timer, the network device has not received the absent transmitted data packets.