Low Power and Lossy Networks (LLNs) are a class of network in which both routers and their interconnect are constrained. LLN routers typically operate with constraints on (any subset of) processing power, memory and energy (battery), and their interconnects are characterized by (any subset of) high loss rates, low data rates, and instability. LLNs comprises of anything from a few dozen to thousands of LLN routers, and support point-to-point traffic (between devices inside the LLN), point-to-multipoint traffic (from a central control point to a subset of devices inside the LLN) and multipoint-to-point traffic (from devices inside the LLN towards a central control point).
The Routing Protocol for Low Power and Lossy Networks feature specifies the IPv6 routing protocol for LLNs, thereby providing a mechanism whereby multipoint-to-point traffic from devices inside the LLN towards a central control point, and point-to-multipoint traffic from the central control point to the devices inside the LLN, is supported. Point-to-point traffic is also supported.
For detailed information about this feature, see the following document: