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Showing papers on "Routing table published in 2011"


Journal ArticleDOI
TL;DR: BUBBLE is designed and evaluated, a novel social-based forwarding algorithm that utilizes the aforementioned metrics to enhance delivery performance and empirically shows that BUBBLE can substantially improve forwarding performance compared to a number of previously proposed algorithms including the benchmarking history-based PROPHET algorithm, and social- based forwarding SimBet algorithm.
Abstract: The increasing penetration of smart devices with networking capability form novel networks Such networks, also referred as pocket switched networks (PSNs), are intermittently connected and represent a paradigm shift of forwarding data in an ad hoc manner The social structure and interaction of users of such devices dictate the performance of routing protocols in PSNs To that end, social information is an essential metric for designing forwarding algorithms for such types of networks Previous methods relied on building and updating routing tables to cope with dynamic network conditions On the downside, it has been shown that such approaches end up being cost ineffective due to the partial capture of the transient network behavior A more promising approach would be to capture the intrinsic characteristics of such networks and utilize them in the design of routing algorithms In this paper, we exploit two social and structural metrics, namely centrality and community, using real human mobility traces The contributions of this paper are two-fold First, we design and evaluate BUBBLE, a novel social-based forwarding algorithm, that utilizes the aforementioned metrics to enhance delivery performance Second, we empirically show that BUBBLE can substantially improve forwarding performance compared to a number of previously proposed algorithms including the benchmarking history-based PROPHET algorithm, and social-based forwarding SimBet algorithm

1,426 citations


Proceedings ArticleDOI
30 Aug 2011
TL;DR: This work proposes an architecture that integrates OpenFlow with WMNs and provides such flow-based routing and forwarding capabilities and implemented a simple solution to solve the problem of client mobility in a WMN which handles the fast migration of client addresses.
Abstract: everal protocols for routing and forwarding in Wireless Mesh Networks (WMN) have been proposed, such as AODV, OLSR or B.A.T.M.A.N. However, providing support for e.g. flow-based routing where flows of one source take different paths through the network is hard to implement in a unified way using traditional routing protocols. OpenFlow is an emerging technology which makes network elements such as routers or switches programmable via a standardized interface. By using virtualization and flow-based routing, OpenFlow enables a rapid deployment of novel packet forwarding and routing algorithms, focusing on fixed networks. We propose an architecture that integrates OpenFlow with WMNs and provides such flow-based routing and forwarding capabilities. To demonstrate the feasibility of our OpenFlow based approach, we have implemented a simple solution to solve the problem of client mobility in a WMN which handles the fast migration of client addresses (e.g. IP addresses) between Mesh Access Points and the interaction with re-routing without the need for tunneling. Measurements from a real mesh testbed (KAUMesh) demonstrate the feasibility of our approach based on the evaluation of forwarding performance, control traffic and rule activation time.

311 citations


Proceedings ArticleDOI
19 Aug 2011
TL;DR: CONET is a content-centric inter-network that provides users with a network access to remote named-resources, rather than to remote hosts, and supports the already proposed "clean-slate" and "overlay" deployment approaches.
Abstract: CONET is a content-centric inter-network that provides users with a network access to remote named-resources, rather than to remote hosts. Named-resources can be either data (named-data) or service-access-points (named-sap), identified by a network-identifier (a name). CONET interconnects CONET Sub Systems, which can be layer-2 networks, layer-3 networks or couples of nodes connected by a point-to-point link. CONET supports the already proposed "clean-slate" and "overlay" deployment approaches. In addition, CONET supports a novel "integration" approach, which extends the IP layer with a new header option that makes IP itself content-aware. CONET limits the size of name-based routing tables by including only a subset of all named-resources; missing entries are looked up in a name-system and then cached. CONET does not maintain states in network nodes, to deliver contents.

268 citations


Journal ArticleDOI
TL;DR: AntNet as mentioned in this paper is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems, which is a novel approach to the adaptive learning of routing tables in communications networks.
Abstract: This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning fields. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and artificial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal traffic distributions. Results are very encouraging. AntNet showed superior performance under all the experimental conditions with respect to its competitors. We analyze the main characteristics of the algorithm and try to explain the reasons for its superiority.

220 citations


Journal ArticleDOI
TL;DR: A new routing/scheduling back-pressure algorithm that not only guarantees network stability (throughput optimality), but also adaptively selects a set of optimal routes based on shortest-path information in order to minimize average path lengths between each source and destination pair is proposed.
Abstract: Back-pressure-type algorithms based on the algorithm by Tassiulas and Ephremides have recently received much attention for jointly routing and scheduling over multihop wireless networks. However, this approach has a significant weakness in routing because the traditional back-pressure algorithm explores and exploits all feasible paths between each source and destination. While this extensive exploration is essential in order to maintain stability when the network is heavily loaded, under light or moderate loads, packets may be sent over unnecessarily long routes, and the algorithm could be very inefficient in terms of end-to-end delay and routing convergence times. This paper proposes a new routing/scheduling back-pressure algorithm that not only guarantees network stability (throughput optimality), but also adaptively selects a set of optimal routes based on shortest-path information in order to minimize average path lengths between each source and destination pair. Our results indicate that under the traditional back-pressure algorithm, the end-to-end packet delay first decreases and then increases as a function of the network load (arrival rate). This surprising low-load behavior is explained due to the fact that the traditional back-pressure algorithm exploits all paths (including very long ones) even when the traffic load is light. On the other-hand, the proposed algorithm adaptively selects a set of routes according to the traffic load so that long paths are used only when necessary, thus resulting in much smaller end-to-end packet delays as compared to the traditional back-pressure algorithm .

218 citations


Proceedings ArticleDOI
10 Apr 2011
TL;DR: SANE is the first forwarding mechanism that combines the advantages of both social-aware and stateless approaches in pocket switched network routing, based on the observation that individuals with similar interests tend to meet more often.
Abstract: In this paper we describe SANE, the first forwarding mechanism that combines the advantages of both social-aware and stateless approaches in pocket switched network routing. SANE is based on the observation“that we validate on real-world traces”that individuals with similar interests tend to meet more often. In our approach, individuals (network members) are characterized by their interest profile, a compact representation of their interests. Through extensive experiments, we show the superiority of social-aware, stateless forwarding over existing stateful, social-aware and stateless, social-oblivious forwarding. An important byproduct of our interest-based approach is that it easily enables innovative routing primitives, such as interest-casting. An interest-casting protocol is also described, and extensively evaluated through experiments based on both real-world and synthetic mobility traces.

212 citations


Journal ArticleDOI
TL;DR: This paper presents a class of routing protocols for vehicular ad hoc networks (VANETs) called the Intersection-based Geographical Routing Protocol (IGRP), which outperforms existing routing schemes in city environments and significantly improves VANET performance when compared with several prominent routing protocols, such as greedy perimeter stateless routing (GPSR), greedy perimeter coordinator routing ( GPCR), and optimized link-state routing (OLSR).
Abstract: This paper presents a class of routing protocols for vehicular ad hoc networks (VANETs) called the Intersection-based Geographical Routing Protocol (IGRP), which outperforms existing routing schemes in city environments. IGRP is based on an effective selection of road intersections through which a packet must pass to reach the gateway to the Internet. The selection is made in a way that guarantees, with high probability, network connectivity among the road intersections while satisfying quality-of-service (QoS) constraints on tolerable delay, bandwidth usage, and error rate. Geographical forwarding is used to transfer packets between any two intersections on the path, reducing the path's sensitivity to individual node movements. To achieve this, we mathematically formulate the QoS routing problem as a constrained optimization problem. Specifically, analytical expressions for the connectivity probability, end-to-end delay, hop count, and bit error rate (BER) of a route in a two-way road scenario are derived. Then, we propose a genetic algorithm to solve the optimization problem. Numerical and simulation results show that the proposed approach gives optimal or near-optimal solutions and significantly improves VANET performance when compared with several prominent routing protocols, such as greedy perimeter stateless routing (GPSR), greedy perimeter coordinator routing (GPCR), and optimized link-state routing (OLSR).

205 citations


Proceedings ArticleDOI
04 Jun 2011
TL;DR: This work designs a novel low-cost congestion propagation network that leverages both local and non-local network information for more accurate congestion estimates and offers effective adaptivity for congestion beyond neighboring nodes, and proposes Destination-Based Adaptive Routing (DBAR).
Abstract: With the emergence of many-core architectures, it is quite likely that multiple applications will run concurrently on a system. Existing locally and globally adaptive routing algorithms largely overlook issues associated with workload consolidation. The shortsightedness of locally adaptive routing algorithms limits performance due to poor network congestion avoidance. Globally adaptive routing algorithms attack this issue by introducing a congestion propagation network to obtain network status information beyond neighboring nodes. However, they may suffer from intra- and inter-application interference during output port selection for consolidated workloads, coupling the behavior of otherwise independent applications and negatively affecting performance. To address these two issues, we propose Destination-Based Adaptive Routing (DBAR). We design a novel low-cost congestion propagation network that leverages both local and non-local network information for more accurate congestion estimates. Thus, DBAR offers effective adaptivity for congestion beyond neighboring nodes. More importantly, by integrating the destination into the selection function, DBAR mitigates intra- and inter-application interference and offers dynamic isolation among regions. Experimental results show that DBAR can offer better performance than the best baseline algorithm for all measured configurations; it is well suited for workload consolidation. The wiring overhead of DBAR is low and DBAR provides improvement in the energy-delay product for medium and high injection rates.

183 citations


Patent
18 Nov 2011
TL;DR: In this paper, a first router and a second router having a shared set of interfaces are provided, enabling the first and second routers to share forwarding data for forwarding packets on the shared set.
Abstract: Methods and apparatus for providing a device for forwarding packets in a network are disclosed. A first router and a second router having a shared set of interfaces are provided, enabling the first router and the second router to share forwarding data for forwarding packets on the shared set of interfaces.

177 citations


Patent
27 Apr 2011
TL;DR: In this article, the authors present a VM-switch locator that corresponds to an identifier of the destination network adapter, and modifies the data packets to include the identifier in order to enforce communication policies that govern data-packet traffic.
Abstract: Computerized methods, systems, and computer-readable media are provided for establishing and managing a virtual network (V-net) and virtual machine (VM) switches that enable protected and isolated interconnections between members of the V-net. The V-net members include an originating network adapter that generates data packets addressed to a destination network adapter. Upon detecting data-packet generation, a source-side VM switch accesses a forwarding table associated with the V-net, ascertains a destination-side, VM-switch locator that corresponds to an identifier of the destination network adapter, and modifies the data packets to include the identifier. The forwarding table represents a mapping between the members of the V-net and VM switches located on respective nodes within the data center. In operation, the mapping enforces communication policies that govern data-packet traffic. Upon receiving the data packets, the destination-side VM switch restores the data packets and forwards them to the destination network adapter.

163 citations


Patent
04 Feb 2011
TL;DR: In this paper, the authors present a system for identifying invalid nodes within a mesh network, where a routing table is maintained by a utility meter and an alert message associated with the identified change may be generated by the utility meter.
Abstract: Systems (100), methods (300), and apparatus for identifying invalid nodes within a mesh network (105) are provided. A routing table (104) may be maintained by a utility meter (120). The routing table (140) may include information associated with one or more devices in communication with the utility meter via a mesh network. A change in the routing table may be identified by the utility meter (120), and an alert message associated with the identified change may be generated by the utility meter (120). The generated alert may then be output by the utility meter for communication to a central controller (110) configured to process the alert message to identify an invalid node within the mesh network.

Patent
30 Aug 2011
TL;DR: In this paper, an Internet Protocol (IP) routing information base of a packet switching device is filtered to produce a significantly smaller subset of IP routes that are installed in one or more forwarding information bases for forwarding of IP packets.
Abstract: In one embodiment, an Internet Protocol (IP) routing information base of a packet switching device is filtered to produce a significantly smaller subset of IP routes that are installed in one or more forwarding information bases for forwarding of IP packets. In one embodiment, these smaller forwarding information bases are located in memory local to a network processor to more quickly perform lookup operations thereon. In one embodiment, one or more of these forwarding information bases is used only for exact matching of addresses (not longest prefix matching). In one embodiment, the IP routes in these smaller forwarding information bases substantially correspond to packet switching devices in a network (e.g., core and edge routers), such as in contrast to including all the IP routes for devices external to the network.

Proceedings ArticleDOI
13 Jun 2011
TL;DR: This paper proposes RouteFlow, a commodity routing architecture that combines the line-rate performance of commercial hardware with the flexibility of open-source routing stacks (remotely) running on general purpose computers and outlines the research agenda that calls for a community-driven approach.
Abstract: The networking equipment market is being transformed by the need for greater openness and flexibility, not only for research purposes but also for in-house innovation by the equipment owners. In contrast to networking gear following the model of computer mainframes, where closed software runs on proprietary hardware, the software-defined networking approach effectively decouples the data from the control plane via an open API (i.e., OpenFlow protocol) that allows the (remote) control of packet forwarding engines. Motivated by this scenario, we propose RouteFlow, a commodity routing architecture that combines the line-rate performance of commercial hardware with the flexibility of open-source routing stacks (remotely) running on general purpose computers. The outcome is a novel point in the design space of commodity routing solutions with far-reaching implications towards virtual routers and IP networks as a service. This paper documents the progress achieved in the design and prototype implementation of our work and outlines our research agenda that calls for a community-driven approach.

Proceedings ArticleDOI
23 Oct 2011
TL;DR: This paper introduces secure network provenance (SNP), a novel technique that enables networked systems to explain to their operators why they are in a certain state -- e.g., why a suspicious routing table entry is present on a certain router, or where a given cache entry originated.
Abstract: This paper introduces secure network provenance (SNP), a novel technique that enables networked systems to explain to their operators why they are in a certain state -- e.g., why a suspicious routing table entry is present on a certain router, or where a given cache entry originated. SNP provides network forensics capabilities by permitting operators to track down faulty or misbehaving nodes, and to assess the damage such nodes may have caused to the rest of the system. SNP is designed for adversarial settings and is robust to manipulation; its tamper-evident properties ensure that operators can detect when compromised nodes lie or falsely implicate correct nodes. We also present the design of SNooPy, a general-purpose SNP system. To demonstrate that SNooPy is practical, we apply it to three example applications: the Quagga BGP daemon, a declarative implementation of Chord, and Hadoop MapReduce. Our results indicate that SNooPy can efficiently explain state in an adversarial setting, that it can be applied with minimal effort, and that its costs are low enough to be practical.

Patent
21 Nov 2011
TL;DR: In this paper, the authors describe a routing protocol for power line communications (PLC) in a mesh network and present a routing table for a plurality of PLC devices in a PLC mesh network.
Abstract: Systems and methods for routing protocols for power line communications (PLC) are described. In some embodiments, a method may include transmitting a one-hop broadcast request message to a plurality of PLC devices in a mesh network and receiving a response from each of the devices. The method may also include selecting one of the devices as a bootstrapping agent, sending a join request to a bootstrapping server through the bootstrapping agent, and, in response to successfully joining the network, setting the bootstrapping agent as a next hop toward a bootstrapping server. In another embodiment, a method may include maintaining a routing table for a plurality of PLC devices in a mesh network, receiving a join request from a PLC device, accepting the request, and updating the table to add a record corresponding to the PLC device; the record setting the bootstrapping agent as a penultimate hop toward the PLC device.

Journal ArticleDOI
TL;DR: A geographical routing algorithm called location-aware routing for delay-tolerant networks (LAROD), enhanced with a location service, location dissemination service (LoDiS), which together are shown to suit an intermittently connected MANET (IC-MANET).
Abstract: Combining mobile platforms such as manned or unmanned vehicles and peer-assisted wireless communication is an enabler for a vast number of applications. A key enabler for the applications is the routing protocol that directs the packets in the network. Routing packets in fully connected mobile ad hoc networks (MANETs) has been studied to a great extent, but the assumption on full connectivity is generally not valid in a real system. This case means that a practical routing protocol must handle intermittent connectivity and the absence of end-to-end connections. In this paper, we propose a geographical routing algorithm called location-aware routing for delay-tolerant networks (LAROD), enhanced with a location service, location dissemination service (LoDiS), which together are shown to suit an intermittently connected MANET (IC-MANET). Because location dissemination takes time in IC-MANETs, LAROD is designed to route packets with only partial knowledge of geographic position. To achieve low overhead, LAROD uses a beaconless strategy combined with a position-based resolution of bids when forwarding packets. LoDiS maintains a local database of node locations, which is updated using broadcast gossip combined with routing overhearing. The algorithms are evaluated under a realistic application, i.e., unmanned aerial vehicles deployed in a reconnaissance scenario, using the low-level packet simulator ns-2. The novelty of this paper is the illustration of sound design choices in a realistic application, with holistic choices in routing, location management, and the mobility model. This holistic approach justifies that the choice of maintaining a local database of node locations is both essential and feasible. The LAROD-LoDiS scheme is compared with a leading delay-tolerant routing algorithm (spray and wait) and is shown to have a competitive edge, both in terms of delivery ratio and overhead. For spray and wait, this case involved a new packet-level implementation in ns-2 as opposed to the original connection-level custom simulator.

Patent
Wenhu Lu1, Albert Jining Tian1
22 Sep 2011
TL;DR: In this article, a router detects a network failure and, responsive to that failure, floods a fast failure notification message out a set of interfaces of the router, including information that identifies the network failure, and includes as its source MAC (Media Access Control) address a MAC address that is assigned to an interface that is coupled with the detected network failure.
Abstract: A router detects a network failure and responsive to that failure, floods a fast failure notification message out a set of interfaces of the router. The fast failure notification message includes information that identifies the network failure and includes as its source MAC (Media Access Control) address a MAC address that is assigned to an interface that is coupled with the detected network failure and is not part of the set of interfaces of the router. The router updates a routing table to reflect the network failure. The flooding of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.

Journal ArticleDOI
TL;DR: In this article, the authors proposed an iterative exact algorithm for vehicle routing with time windows and multiple routes, which considers that a given vehicle can be assigned to more than one route per planning period.

Journal ArticleDOI
01 Mar 2011
TL;DR: The proposed connectivity-aware minimum-delay geographic routing protocol for vehicular ad hoc networks (VANETs), which adapts well to continuously changing network status in such networks, is compared with two plausible geographic connectivity- aware routing protocols for VANets, A-STAR and VADD.
Abstract: In this paper, we propose the connectivity-aware minimum-delay geographic routing (CMGR) protocol for vehicular ad hoc networks (VANETs), which adapts well to continuously changing network status in such networks. When the network is sparse, CMGR takes the connectivity of routes into consideration in its route selection logic to maximize the chance of packet reception. On the other hand, in situations with dense network nodes, CMGR determines the routes with adequate connectivity and selects among them the route with the minimum delay. The performance limitations of CMGR in special vehicular networking situations are studied and addressed. These situations, which include the case where the target vehicle has moved away from its expected location and the case where traffic in a road junction is so sparse that no next-hop vehicle can be found on the intended out-going road, are also problematic in most routing protocols for VANETs. Finally, the proposed protocol is compared with two plausible geographic connectivity-aware routing protocols for VANETs, A-STAR and VADD. The obtained results show that CMGR outperforms A-STAR and VADD in terms of both packet delivery ratio and ratio of dropped data packets. For example, under the specific conditions considered in the simulations, when the maximum allowable one-way transmission delay is 1min and one gateway is deployed in the network, the packet delivery ratio of CMGR is approximately 25% better than VADD and A-STAR for high vehicle densities and goes up to 900% better for low vehicle densities.

Proceedings ArticleDOI
Binzhang Fu1, Yinhe Han1, Jun Ma1, Huawei Li1, Xiaowei Li1 
04 Jun 2011
TL;DR: The abacus-turn-model (AbTM) is proposed for designing time/space-efficient reconfigurable wormhole routing algorithms and its applicability with scalable performance in large-scale NoC applications is proved.
Abstract: Applications' traffic tends to be bursty and the location of hot-spot nodes moves as time goes by. This will significantly aggregate the blocking problem of wormhole-routed Network-on-Chip (NoC). Most of state-of-the-art traffic balancing solutions are based on fully adaptive routing algorithms which may introduce large time/space overhead to routers. Partially adaptive routing algorithms, on the other hand, are time/space efficient, but lack of even or sufficient routing adaptiveness. Reconfigurable routing algorithms could provide on-demand routing adaptiveness for reducing blocking, but most of them are off-line solutions due to the lack of a practical model to dynamically generate deadlock-free routing algorithms. In this paper, we propose the abacus-turn-model (AbTM) for designing time/space-efficient reconfigurable wormhole routing algorithms. Unlike the original turn model, AbTM exploits dynamic communication patterns in applications to reduce the routing latency and chip area requirements. We apply forbidden turns dynamically to preserve deadlock-free operations. Our AbTM routing architecture has two distinct advantages: First, the AbTM leads to a new router architecture without adding virtual channels and routing table. This reconfigurable architecture updates the routing path once the communication pattern changes, and always provides full adaptiveness to hot-spot directions to reduce network blocking. Secondly, the reconfiguration scheme has a good scalability because all operations are carried out between neighbors. We demonstrate these advantages through extensive simulation experiments. The experimental results are indeed encouraging and prove its applicability with scalable performance in large-scale NoC applications.

Proceedings ArticleDOI
07 Nov 2011
TL;DR: Lookahead routing is developed to give the placer advance, firsthand knowledge of trouble spots, not distorted by crude congestion models, and global placement is extended to spread cells apart in congested areas, and move cells together in less-congested areas to ensure short, routable interconnects and moderate runtime.
Abstract: Highly-optimized placements may lead to irreparable routing congestion due to inadequate models of modern interconnect stacks and the impact of partial routing obstacles. Additional challenges in routability-driven placement include scalability to large netlists and limiting the complexity of software integration. Addressing these challenges, we develop lookahead routing to give the placer advance, firsthand knowledge of trouble spots, not distorted by crude congestion models. We also extend global placement to (i) spread cells apart in congested areas, and (ii) move cells together in less-congested areas to ensure short, routable interconnects and moderate runtime. While previous work adds isolated steps to global placement, our SIMultaneous PLace-and-Route tool SimPLR integrates a layer- and via-aware global router into a leading-edge, force-directed placer. The complexity of integration is mitigated by careful design of simple yet effective optimizations. On the ISPD 2011 Contest Benchmark Suite, with the official evaluation protocol, SimPLR outperforms every contestant on every benchmark.

Patent
15 Jun 2011
TL;DR: In this paper, the authors present methods, systems, and computer readable media for providing dynamic origination-based routing key registration in a DIAMETER network and present a routing rule is automatically generated, at he first DIAMetER node, based on the received origin-based information.
Abstract: Methods, systems, and computer readable media for providing dynamic origination-based routing key registration in a DIAMETER network are disclosed. According to one method, origin-based routing information is received, at a first DIAMETER node, from a second DIAMETER node. The origin-based routing information specifies one or more sources such that traffic originating from one of the one or more sources should be routed to the second DIAMETER node. A routing rule is automatically generated, at he first DIAMETER node, based on the received origin-based routing information.

Proceedings ArticleDOI
28 Mar 2011
TL;DR: The analysis of the ns-3 simulations shows AeroRP has several advantages over other MANET routing protocols in terms of PDR, accuracy, delay, and overhead, and AeroRP offers performance tradeoffs in the form of different AeroRP modes.
Abstract: Emerging networked systems require domain-specific routing protocols to cope with the challenges faced by the aeronautical environment. We present a geographic routing protocol AeroRP for multihop routing in highly dynamic MANETs. The AeroRP algorithm uses velocity-based heuristics to deliver the packets to destinations in a multi-Mach speed environment. Furthermore, we present the decision metrics used to forward the packets by the various AeroRP operational modes. The analysis of the ns-3 simulations shows AeroRP has several advantages over other MANET routing protocols in terms of PDR, accuracy, delay, and overhead. Moreover, AeroRP offers performance tradeoffs in the form of different AeroRP modes.

Proceedings ArticleDOI
10 Apr 2011
TL;DR: It is shown that the parameters of the filter need to be varied to guarantee the stability of the packet forwarding, and a bit permutation technique is presented that effectively prevents both accidental and maliciously created anomalies.
Abstract: Several recently proposed multicast protocols use in-packet Bloom filters to encode multicast trees. These mechanisms are in principle highly scalable because no per-flow state is required in the routers and because routing decisions can be made efficiently by simply checking for the presence of outbound links in the filter. Yet, the viability of previous approaches is limited by the possibility of forwarding anomalies caused by false positives inherent in Bloom filters. This paper explores such anomalies, namely (1) packets storms, (2) forwarding loops and (3) flow duplication. We propose stateless solutions that increase the robustness and the scalability of Bloom filter-based multicast protocols. In particular, we show that the parameters of the filter need to be varied to guarantee the stability of the packet forwarding, and we present a bit permutation technique that effectively prevents both accidental and maliciously created anomalies. We evaluate our solutions in the context of BloomCast, a source-specific inter-domain multicast protocol, using analytical methods and simulations.

01 Oct 2011
TL;DR: This document describes Contact Graph Routing (CGR), a procedure for computing efficient Delay-Tolerant Networking (DTN) bundle forwarding routes between source and destination endpoints when connectivity between pairs of neighboring bundle protocol agents in the network is scheduled and episodic rather than continuous.
Abstract: Contact Graph Routing (CGR) is a dynamic routing system that computes routes through a time-varying topology of scheduled communication contacts in a network based on the DTN (Delay-Tolerant Networking) architecture. It is designed to enable dynamic selection of data transmission routes in a space network based on DTN. This dynamic responsiveness in route computation should be significantly more effective and less expensive than static routing, increasing total data return while at the same time reducing mission operations cost and risk. The basic strategy of CGR is to take advantage of the fact that, since flight mission communication operations are planned in detail, the communication routes between any pair of bundle agents in a population of nodes that have all been informed of one another's plans can be inferred from those plans rather than discovered via dialogue (which is impractical over long one-way-light-time space links). Messages that convey this planning information are used to construct contact graphs (time-varying models of network connectivity) from which CGR automatically computes efficient routes for bundles. Automatic route selection increases the flexibility and resilience of the space network, simplifying cross-support and reducing mission management costs. Note that there are no routing tables in Contact Graph Routing. The best route for a bundle destined for a given node may routinely be different from the best route for a different bundle destined for the same node, depending on bundle priority, bundle expiration time, and changes in the current lengths of transmission queues for neighboring nodes; routes must be computed individually for each bundle, from the Bundle Protocol agent's current network connectivity model for the bundle s destination node (the contact graph). Clearly this places a premium on optimizing the implementation of the route computation algorithm. The scalability of CGR to very large networks remains a research topic. The information carried by CGR contact plan messages is useful not only for dynamic route computation, but also for the implementation of rate control, congestion forecasting, transmission episode initiation and termination, timeout interval computation, and retransmission timer suspension and resumption.

Journal ArticleDOI
TL;DR: The basic concepts ofortunistic routing are reviewed and components of OR are described with examples, and current trends, issues and challenges of Or are discussed.

Journal ArticleDOI
TL;DR: A deadlock-free routing architecture which employs a dynamic programming (DP) network to provide on-the-fly optimal path planning and network monitoring for packet switching and a new routing strategy called k-step look ahead is introduced.
Abstract: Dynamic routing is desirable because of its substantial improvement in communication bandwidth and intelligent adaptation to faulty links and congested traffic. However, implementation of adaptive routing in a network-on-chip system is not trivial and is further complicated by the requirements of deadlock-free and real-time optimal decision making. In this paper, we present a deadlock-free routing architecture which employs a dynamic programming (DP) network to provide on-the-fly optimal path planning and network monitoring for packet switching. Also, a new routing strategy called k-step look ahead is introduced. This new strategy can substantially reduce the size of routing table and maintain a high quality of adaptation which leads to a scalable dynamic-routing solution with minimal hardware overhead. Our results, based on a cycle-accurate simulator, demonstrate the effectiveness of the DP network, which outperforms both the deterministic and adaptive-routing algorithms in average delay on various traffic scenarios by 22.3%. Moreover, the hardware overhead for DP network is insignificant, based on the results obtained from the hardware implementations.

Journal ArticleDOI
TL;DR: The optimal network throughput regions are characterized under the above described NSI models and it is shown that the throughput regions shrinks with the increase of delay.
Abstract: The problem of routing/scheduling in a wireless network with partial/delayed network (channel and queue) state information (NSI) is studied in this paper. Two cases are considered: (i) centralized routing/scheduling, where a central controller obtains heterogeneously delayed information from each of the nodes (thus, the controller has NSI with different delays from different nodes), and makes routing/scheduling decisions; (ii) decentralized routing/scheduling, where each node makes a decision based on its current channel and queue states along with homogeneous delayed NSI from other nodes. For each of the cases (with additional flow restrictions for the decentralized routing/scheduling case), the optimal network throughput regions are characterized under the above described NSI models and it is shown that the throughput regions shrinks with the increase of delay. Further, channel and queue length based routing/scheduling algorithms that achieve the above throughput regions are proposed in this paper.

Journal ArticleDOI
TL;DR: It is proved that construction of a minimum α-MOC-CDS is NP-hard in a general graph and a heuristic algorithm is proposed for construction of α- MOC- CDS to improve the performance of CDS based broadcasting and routing.
Abstract: Topology control is one vital factor to a wireless network's efficiency. A Connected Dominating Set (CDS) can be a useful basis of a backbone topology construction. In this paper, a special CDS, named α Minimum routing Cost CDS (α-MOC-CDS), will be studied to improve the performance of CDS based broadcasting and routing. In this paper, we prove that construction of a minimum α-MOC-CDS is NP-hard in a general graph and we propose a heuristic algorithm for construction of α-MOC-CDS.

Proceedings ArticleDOI
06 Dec 2011
TL;DR: SMALTA is presented, a practical, near-optimal FIB aggregation scheme that shrinks forwarding table size without modifying routing semantics or the external behavior of routers, and without requiring changes to FIB lookup algorithms and associated hardware and software.
Abstract: IP Routers use sophisticated forwarding table (FIB) lookup algorithms that minimize lookup time, storage, and update time. This paper presents SMALTA, a practical, near-optimal FIB aggregation scheme that shrinks forwarding table size without modifying routing semantics or the external behavior of routers, and without requiring changes to FIB lookup algorithms and associated hardware and software. On typical IP routers using the FIB lookup algorithm Tree Bitmap, SMALTA shrinks FIB storage by at least 50%, representing roughly four years of routing table growth at current rates. SMALTA also reduces average lookup time by 25% for a uniform traffic matrix. Besides the benefits this brings to future routers, SMALTA provides a critical easy-to-deploy one-time benefit to the installed base should IPv4 address depletion result in increased routing table growth rate. The effective cost of this improvement is a sub-second delay in inserting updates into the FIB once every few hours. We describe SMALTA, prove its correctness, measure its performance using data from a Tier-1 provider as well as Route-Views. We also describe an implementation in Quagga that demonstrates its ease of implementation.