Multicast transmissions do not allow for individual receivers to acknowledge that data was received by each receiver in the network. This is not acceptable for isochronous systems that require specific levels of QoS for each device. A multimedia communications protocol supports using multicast transmissions (one-to-many) in multimedia isochronous systems. A transmitter establishes a Multi-ACKed Multicast protocol within which a group of receiving devices can acknowledge the multicast transmission during a multi-acknowledgment period.