A Depth First Forwarding (DFF) Extension for the LOADng Routing Protocol

International audienceThis paper explores the cooperation between the new standards for "Low Power and Lossy Networks" (LLNs): IETF RFC 6971, denoted "Depth-First Forwarding in Unreliable Networks" (DFF) and the ITU-T standardised routing protocol "LOADng" (Lightweight On-demand ad hoc Distance-vector Routing-next generation). DFF is a data-forwarding mechanism for increasing reliability of data delivery in networks with dynamic topology and lossy links, using a mechanism similar to a "depth-first search" for the destination of a packet. LOADng is a reactive on-demand routing protocol used in LLNs. The purpose of this study is to evaluate the benefit of using DFF conjointly with a routing protocol. To this end, the paper compares the performance of LOADng and LOADng+DFF using Ns2 simulations, showing a 20% end-to-end data delivery ratio increase at expense of expected longer path lengths

Depth-First Forwarding for Unreliable Networks: Extensions and Applications

International audienceThis paper introduces extensions and applications of Depth-First Forwarding (DFF)-a data forwarding mechanism for use in unreliable networks such as sensor networks and mobile ad hoc networks with limited computational power and storage, low-capacity channels, device mobility, etc. Routing protocols for these networks try to balance conflicting requirements of being reactive to topology and channel variation while also being frugal in resource requirements-but when the underlying topology changes, routing protocols require time to re-converge, during which data delivery failure may occur. DFF was developed to alleviate this situation: it reacts rapidly to local data delivery failures and attempts to successfully deliver data while giving a routing protocol time to recover from such a failure. An extension of DFF, denoted DFF++, is proposed in this paper, in order to optimise the performance of DFF by way of introducing a more efficient search ordering. This paper also studies the applicability, of DFF to three major routing protocols for the "Internet of Things", including the Lightweight On-demand Ad hoc Distance-vector Routing Protocol-Next Generation (LOADng), the Optimized Link State Routing protocol version 2 (OLSRv2), and the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL), and presents the performance of these protocols, with and without DFF, in lossy and unreliable networks