Equal-cost multi-path routing

About: Equal-cost multi-path routing is a research topic. Over the lifetime, 10472 publications have been published within this topic receiving 249362 citations.

Enhancing Contact Graph Routing for Delay Tolerant Space Networking

Abstract: When designing routing protocols for space-based networks, we must take into consideration the unique characteristics of such networks. Since space-based networks are inherently sparse with constrained resources, one needs to design smart routing algorithms that use the resources efficiently to maximize network performance. In Space Exploration Missions, the trajectories and orbits of spacecraft are predetermined, thus communication opportunities are predictable. This a-priori knowledge can be used to the advantage of scheduling and routing. In this paper, we focus on analyzing Contact Graph Routing (CGR) for space-based networks. CGR makes use of the predictable nature of the contacts to make routing decisions. Mars and Lunar mission-like scenarios were used in our simulations to gather statistics on routing protocol performance in terms of delay and buffer usage. We provide improvements to the underlying cost function of CGR to avoid routing loops and suggest applying Dijkstra's shortest path algorithm for path selection. The cost function change was incorporated into the latest Internet Draft posted for CGR. Dijkstra's shortest path algorithm was successfully implemented and tested in NASA's Interplanetary Overlay Network (ION) implementation of the DTN protocols.

Fast algorithms for routing around faults in multibutterflies and randomly-wired splitter networks

Abstract: Simple deterministic O(log N)-step algorithms for routing permutations of packets in multibutterflies and randomly wired splitter networks are described. The algorithms are robust against faults (even in the worst case), and are efficient from a practical point of view. As a consequence, it is found that the multibutterfly is an excellent candidate for a high-bandwidth low-diameter switching network underlying a shared-memory machine. >

Opportunistic Routing Algebra and its Applications

Abstract: Opportunistic routing (OR) has received much attention as a new routing paradigm due to its efficient utilization of broadcasting and spacial diversity of the wireless medium. Although numerous OR algorithms and protocols have been proposed to apply to various environments and integrate with numerous techniques, as far as we know, none of the existing works have used mathematical tools such as routing algebra to analyze the compatibility of routing metrics and routing protocols so as to provide a guideline for routing protocol design. In this paper, we design a new OR algebra based on the routing algebra proposed for inter-domain routing, identify the essential properties of OR in the mathematical language of the OR algebra, and analyze the design space in terms of routing metrics for various routing requirements.

Providing dynamic routing alternatives based on determined traffic conditions

Abstract: Methods, devices, and systems are provided to determine traffic conditions along a traffic path and dynamically present one or more entities with at least one alternate route. The alternate route is determined based on a number of entities along the traffic path and available routing points adjacent to the traffic conditions. The alternate route may be configured to optimize traffic for an entire traffic system rather than only optimizing traffic for receivers of the alternate routes. Data relating to the alternate routes presented to the entities can be tracked. This data may be used to evaluate an effectiveness of the routing decisions made. Effectiveness can be measured in cost and time saved or spent. Information, such as the data, determinations of the data, and/or even effectiveness of alternate routes, can be distributed to one or more parties. Distribution of the information may be associated with a tiered cost structure.

Multipath routing in wireless mesh networks

Abstract: Multipath Routing in Wireless Mesh Networks Marc Mosko ∗ Palo Alto Research Center 3333 Coyote Hill Road Palo Alto, CA 94304 Email: mmosko@parc.com Abstract— This paper addresses multipath routing in a mobile wireless network. We review the premise that a routing protocol should prefer disjoint path construction and argue that using disjoint paths limits route reliability in mobile ad hoc networks compared to using multiple loop-free paths that need not be disjoint. In a mobile ad hoc network, link lifetimes may be relatively short compared to traffic flows. The characteristics of a MANET are significantly different than the networks considered by Kleinrock in his original delay analysis of alternate path routing. In particular, on-demand routing protocols may suffer a significant delay during path discovery. We argue that a routing protocol should exploit the mesh connectivity over non-disjoint loop-free paths to improve s, t-connectedness lifetime in a mobile network. Exploiting mesh connectivity amortizes expensive path discovery operations and may lead to better performance than using disjoint or maximally disjoint paths. I. I NTRODUCTION The main objective of using multipath routing in a mobile ad hoc network is to use several good paths to reach destinations, not just the one best path [1], without imposing excessive control overhead in maintaining such paths. Multipath routing has long been recognized as an important feature in networks to adapt to load and increase reliability [2], [3]. Telecommunication networks adopted alternate path rout- ing, really a form of path failover, in 1984 [4]. Many routing papers on ad hoc routing suggest that the proposed routing protocol may operate correctly (i.e., provide multiple loop- free paths), without specifically addressing the performance of the protocol when multipaths 1 are used [5]–[9]. Other protocols suggest building alternate paths, but without claims of correct operation (e.g. [10]–[13]). Several papers measure route coupling [14]–[16], the mutual interference of routes in a common-channel multi-hop ad hoc network, and find routes with low coupling. Route coupling, however, makes every flow dependent on every other flow through an area and the papers on route coupling do not address the cost of maintaining low- coupled routes in an on-demand protocol; they typically use link-state pro-active protocols. Most of the works on ad hoc multipath restrict the number of potential routes to a small number, usually two. AOMDV [17] allows up to k link-disjoint RREPs, where one is the “quickest” path and the others are chosen from the next link-disjoint RREQs. SMR [18] builds two paths from the quickest RREQ and then collects RREQs 1 We use the term ”multipath” to denote a set of multiple paths to a destination that need not be node or edge disjoint. J.J. Garcia-Luna-Aceves ∗† Computer Engineering Department University of California at Santa Cruz Santa Cruz, CA 95064 Email: jj@soe.ucsc.edu for a period and chooses a second maximally disjoint path from the first. In a zone-disjoint scheme [16], only two paths are built, but they are not necessarily minimum. This scheme uses an iterative algorithm to discard the worst choice each round until only two paths are left. In this paper, we argue that a routing protocol for ad hoc networks should fully exploit the rich connectivity of the network to improve the reliability of packet delivery. In a nutshell, a well-designed multipath routing protocol should find many alternate loop-free paths to destinations and should keep those paths alive by sending some amount of data traffic over them as a function of their quality. Paths with poor quality or significantly longer distance should not be used. The exact methods used by a routing protocol to propagate metrics and distribute load between paths is an open ques- tion. Interestingly, a number of routing protocols for ad hoc networks that attempt to take advantage of multiple paths to destinations advocate the use of node- or edge-disjoint paths. Section II surveys the literature and makes the case that disjoint paths are not necessary to improve the reliability of wireless ad hoc networks. Furthermore, Section III shows that multiple well-connected loop-free paths offer substantially longer path lifetimes than sets of disjoint paths. Based on these results, Section IV illustrates a multipath routing approach in which node or edge disjoint paths are not enforced, using the DOS [19] routing protocol as an example. Section V summarizes the implementation of DOS used in the simulation study presented in Section VI, which compares the path distributions of our loop-free on-demand routing protocol and shows that we can maintain between 1.2 and 1.5 paths per hop, without any special path maintenance mechanisms. In 100-node simulations, the multipath scheme has about 1/3 the network load of min-hop multipath and a slightly higher delivery ratio. II. P RIOR W ORK In the literature, there are several types of disjoint paths. In two node disjoint paths, P 1 and P 2 , there is no common nodes except the first (source) and last (destination). In link disjoint paths, there are no common edges, though there may be common nodes. P 1 = {s, a, b, c, t} and P 2 = {s, m, b, n, t} are two link-disjoint paths, although they share the node b. There are also zone disjoint paths, which try to keep paths separated by some number of hops. Two “maximally”