Common Ancestor Objective Function and Parent Set DAG Metric Container Extension
draft-ietf-roll-nsa-extension-14

High reliability and low jitter can be achieved by being able to send   data packets through multiple paths, via different parents, in a   network.  This document details how to exchange the necessary   information within RPL control packets to let a node better select   the different parents that will be used to forward a packet over   different paths.  This document also describes the Objective Function   which takes advantage of this information to implement multi-path   routing.