A method for operating a memory buffer system implemented at a sender station connectable to a communication network for the fast data transport over the communication network with a reliable transport protocol working in a point-to-multipoint data transfer mode, wherein the memory buffer system comprises a send buffer comprising data cells in which the data units ready to be sent over the communication network are stored and in which the data units are stored which have been sent over the communication network with corresponding data packets but not being completely acknowledged by the receiving stations of said point-to-multipoint data communication mode, wherein the memory buffer system further comprises a meta-storage buffer comprising cells in which the meta-data in the form of protocol-dependent parameters for the data packets which have been sent over the communication network but not being completely acknowledged are stored, whereby: - with a sending thread which is responsible for sending data packets to a multipoint receiver group, adding the meta-data for a sent data packet into a next free cell of the meta-storage buffer , thereby shifting a first descriptor, ActiveCellsEndDescr, pointing to the end of the occupied cells range in the meta-storage forward; - with a receiver servicing thread which is responsible for the adding of meta-data into the meta-storage buffer removing a cell from the range of occupied cells in the meta-storage buffer in the case that it is found that the corresponding data packet has been completely acknowledged by all active receivers in the point-to-multipoint communication mode, thereby shifting a second descriptor, ActiveCellsBeginDescr, pointing to the beginning of the occupied cells range in the meta-storage forward; and in the receiver servicing thread checking whether an acknowledgment message from the multipoint receivers is missing for the corresponding data packet thereby checking if the receiver from which an acknowledgement message is missing is in an inactive state, wherein in case the missing acknowledgment message is not from an inactive receiver, declaring the data packet to be a candidate for retransmission over the communication network to at least the multipoint receiver from which the acknowledgment message is missing. - with a sending thread which is responsible for sending data packets to a multipoint receiver group, adding the meta-data for a sent data packet into a next free cell of the meta-storage buffer , thereby shifting a first descriptor, ActiveCellsEndDescr, pointing to the end of the occupied cells range in the meta-storage forward; - with a receiver servicing thread which is responsible for the adding of meta-data into the meta-storage buffer removing a cell from the range of occupied cells in the meta-storage buffer in the case that it is found that the corresponding data packet has been completely acknowledged by all active receivers in the point-to-multipoint communication mode, thereby shifting a second descriptor, ActiveCellsBeginDescr, pointing to the beginning of the occupied cells range in the meta-storage forward; and in the receiver servicing thread checking whether an acknowledgment message from the multipoint receivers is missing for the corresponding data packet thereby checking if the receiver from which an acknowledgement message is missing is in an inactive state, wherein in case the missing acknowledgment message is not from an inactive receiver, declaring the data packet to be a candidate for retransmission over the communication network to at least the multipoint receiver from which the acknowledgment message is missing. <EOS>