Showing papers by "Thomas Clausen published in 2015"

Depth-First Forwarding for Unreliable Networks: Extensions and Applications

Abstract: This 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 as DFF++, is proposed in this paper, in order to optimize 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 (IoT), 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.

Multi-Topology Extension for the Optimized Link State Routing Protocol Version 2 (OLSRv2)

Abstract: This specification describes an extension to the Optimized Link State Routing Protocol version 2 (OLSRv2) to support multiple routing topologies, while retaining interoperability with OLSRv2 routers that do not implement this extension. This specification updates RFCs 7188 and 7631 by modifying and extending TLV registries and descriptions.

An Optimization for the Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)

Abstract: The link quality mechanism of the MANET Neighborhood Discovery Protocol (NHDP) enables "ignoring" some 1-hop neighbors if the measured link quality from that 1-hop neighbor is below an acceptable threshold, while still retaining the corresponding link information as acquired from HELLO message exchange. This allows immediate reinstatement of the 1-hop neighbor if the link quality later improves sufficiently. NHDP also collects information about symmetric 2-hop neighbors. However it specifies that if a link from a symmetric 1-hop neighbor ceases being symmetric, including while "ignored" as described above, then corresponding symmetric 2-hop neighbors are removed. This may lead to symmetric 2-hop neighborhood information being permanently removed (until further HELLO messages are received) if the link quality of a symmetric 1-hop neighbor drops below the acceptable threshold, even if only for a moment. This specification updates RFC6130 "Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)", and RFC7181 "The Optimized Link State Routing Protocol version 2 (OLSRv2)" to permit retaining, but ignoring, symmetric 2-hop information when the link quality from the corresponding 1-hop neighbor drops below the acceptable threshold. This allows immediate reinstatement of the symmetric 2-hop neighbor if the link quality later improves sufficiently, thus making the symmetric 2-hop neighborhood more "robust".

TLV Naming in the Mobile Ad Hoc Network (MANET) Generalized Packet/Message Format

Abstract: This document reorganizes the naming of already-allocated TLV (type- length-value) types and type extensions in the "Mobile Ad hoc NETwork (MANET) Parameters" registries defined by RFC 5444 to use names appropriately. It has no consequences in terms of any protocol implementation. This document also updates the Expert Review guidelines in RFC 5444, so as to establish a policy for consistent naming of future TLV type and type extension allocations. It makes no other changes to RFC 5444.

Jitter Consideration for Reactive Protocols in Mobile Ad Hoc Networks (MANETs)

Abstract: This document provides recommendations for jittering (randomly timing) of routing control message transmission, especially route request dissemination, in reactive protocols of Mobile Ad Hoc Networks, to reduce the probability of collisions, decrease routing overhead, and help finding the optimum paths in the network.

Source-Destination Routing for Optimised Link State Routing Protocol

Abstract: Typical routing protocols maintain, in their RIB (Routing Information Base) entries permitting destination-based forwarding: for a given data packet, the choice of next hop is a function of the destination address only. However, in deployments where a given network is multi-homed, and where ingress filtering is commonly applied, a routing protocol is required to be able to provide routes so as to forward a data packet (i) to the destination address of the data packet, while (ii) routing through the gateway for which the source address of the data packet is topologically correct. This is called source-destination routing. This paper presents an extension to the Optimized Link State Routing Protocol version 2 (OLSRv2), providing support for such source-destination routing. In a multi- homed network, this OLSRv2 extension provides routes for data packets based also on the source prefix announced by the gateways. The extension is interoperable with unextended OLSRv2. The performance of this extension is quantified by way of simulation studies.