Reliable multicast faces the challenge of extending reliability in form of the exactly once delivery semantics or its less strict cousins to communication where data is sent from a single sender to multiple recipients. A straightforward approach is to use the acknowledgements as in reliable unicast.
References.Â
Levine B. N., Garcia-Luna-Aceves J. J.: A Comparison of Known Classes of Reliable Multicast Protocols
Pingali S., Towsley D., Kurose J. F.: A Comparison of Sender-Initiated and Receiver-Initiated Reliable Multicast Protocols