The present invention provides a scalable and reliable feedback suppression method for receiving and transmitting data block. The method comprises receiving at least one initial data packet of the data block which is sent by the transmitter to the multicast group of receivers; and sending at least one NAK packet indicating packet loss to the transmitter by at least one receiver of the multicast group, wherein the at least one NAK packet is sent in a single uplink time slot dedicated to said multicast group of receivers, and wherein the NAK packet is identical for all receivers of said multicast group.