Patent ID: 8520676

Claim:
A method of distributing a multicast message in a Low power and Lossy Network (LLNs), the method comprising: receiving, at a first node in a multicast network, a multicast message from a parent node of the first node; transmitting the multicast message to child nodes of the first node in the multicast network; accessing a population of the child nodes to which the multicast message was transmitted; receiving, at the first node in the multicast network, acknowledgement messages which reveal child nodes that are among an acknowledging subset of less than all of the child nodes of the first node; comparing child nodes revealed by the received acknowledgement messages with child nodes determined to be among the population of child nodes to which the multicast message was transmitted; identifying, based on results of the comparison of child nodes revealed by the received acknowledgement messages with child nodes determined to be among the population of child nodes by which the multicast message is expected to be received, a non-acknowledging subset of less than all of the child nodes from which the acknowledgement message has not yet been received; and transmitting an indication of the non-acknowledging nodes to the parent node of the first node.