In a particular communication network, the server broadcasts a packet of data $($say$,$ L bytes long$)$ to N receivers. The server then waits to receive an acknowl$-$ edgment message from each of the N receivers before proceeding to broadcast the next packet. If the server does not receive all the acknowledgments within a certain time period, it will rebroadcast $($retransmit$)$ the same packet. The server is then said to be in the $$retransmission mode.$$ It will continue retransmitting the packet until all N acknowledgments are received.