Study on Reliable Multicast Transport Protocol

Multicast technology is required in tactical network for supporting the multicast applications,such as situational awareness and task collaboration.Radio communication could provide support for the multicast in tactical communications,but for its unreliability it could not be directly applied in practice if without any control.Thus,a Negative-ACKnowledgment(NACK) Oriented Reliable Multicast(NORM) protocol is proposed,which could provide reliable end-to-end data transportation over generic IP multicast routing and forwarding services.This paper analyzes in detail the key techniques of NORM protocol,including acknowledgment mechanism,congestion control,packet-level FEC and so on,then gives the research difficulties in this field,and finally forecasts the future prospects.