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Showing papers on "Routing table published in 2008"


Journal ArticleDOI
01 Jun 2008
TL;DR: The dragonfly topology is introduced which uses a group of high-radix routers as a virtual router to increase the effective radix of the network and the use of selective virtual-channel discrimination and theUse of credit round-trip latency to both sense and signal channel congestion gives throughput and latency that approaches that of an ideal adaptive routing algorithm.
Abstract: Evolving technology and increasing pin-bandwidth motivate the use of high-radix routers to reduce the diameter, latency, and cost of interconnection networks. High-radix networks, however, require longer cables than their low-radix counterparts. Because cables dominate network cost, the number of cables, and particularly the number of long, global cables should be minimized to realize an efficient network. In this paper, we introduce the dragonfly topology which uses a group of high-radix routers as a virtual router to increase the effective radix of the network. With this organization, each minimally routed packet traverses at most one global channel. By reducing global channels, a dragonfly reduces cost by 20% compared to a flattened butterfly and by 52% compared to a folded Clos network in configurations with ≥ 16K nodes.We also introduce two new variants of global adaptive routing that enable load-balanced routing in the dragonfly. Each router in a dragonfly must make an adaptive routing decision based on the state of a global channel connected to a different router. Because of the indirect nature of this routing decision, conventional adaptive routing algorithms give degraded performance. We introduce the use of selective virtual-channel discrimination and the use of credit round-trip latency to both sense and signal channel congestion. The combination of these two methods gives throughput and latency that approaches that of an ideal adaptive routing algorithm.

641 citations


Journal ArticleDOI
TL;DR: The state of the art in WMN metrics is analyzed and a taxonomy for WMN routing protocols is proposed and performance measurements for a WMN, deployed using various routing metrics, are presented and corroborate the analysis.
Abstract: WMNs are low-cost access networks built on cooperative routing over a backbone composed of stationary wireless routers. WMNs must deal with the highly unstable wireless medium. Therefore, the design of algorithms that consider link quality to choose the best routes are enabling routing metrics and protocols to evolve. In this work, we analyze the state of the art in WMN metrics and propose a taxonomy for WMN routing protocols. Performance measurements for a WMN, deployed using various routing metrics, are presented and corroborate our analysis.

319 citations


Patent
30 Jul 2008
TL;DR: In this paper, a network router includes a plurality of interfaces configured to send and receive packets, and a routing component comprising: (i) a routing engine that includes a control unit that executes a routing protocol to maintain routing information specifying routes through a network, and (ii) a forwarding plane configured by the routing engine to select next hops for the packets in accordance with the routing information.
Abstract: A network router includes a plurality of interfaces configured to send and receive packets, and a routing component comprising: (i) a routing engine that includes a control unit that executes a routing protocol to maintain routing information specifying routes through a network, and (ii) a forwarding plane configured by the routing engine to select next hops for the packets in accordance with the routing information. The forwarding plane comprises a switch fabric to forward the packets to the interfaces based on the selected next hops. The network router also includes a security plane configured to apply security functions to the packets. The security plane is integrated within the network router to share a streamlined forwarding plane of the routing component.

306 citations


Proceedings ArticleDOI
08 Jun 2008
TL;DR: A reconfigurable routing algorithm for a 2D-mesh network-on-chip (NoC) dedicated to fault- tolerant, massively parallel multi-processors systems on chip (MP2-SoC) and evaluated from the point of view of performance, cost, and penalty on the network saturation threshold.
Abstract: In this paper we present a reconfigurable routing algorithm for a 2D-mesh network-on-chip (NoC) dedicated to fault- tolerant, massively parallel multi-processors systems on chip (MP2-SoC). The routing algorithm can be dynamically reconfigured, to adapt to the modification of the micro-network topology caused by a faulty router. This algorithm has been implemented in a reconfigurable version of the DSPIN micro-network, and evaluated from the point of view of performance (penalty on the network saturation threshold), and cost (extra silicon area occupied by the reconfigurable version of the router).

241 citations


Journal ArticleDOI
17 Aug 2008
TL;DR: It is argued that far more significant network-wide benefits can be derived by redesigning network routing protocols to leverage the universal deployment of packet-level redundant content elimination as a universal primitive on all Internet routers.
Abstract: Many past systems have explored how to eliminate redundant transfers from network links and improve network efficiency. Several of these systems operate at the application layer, while the more recent systems operate on individual packets. A common aspect of these systems is that they apply to localized settings, e.g. at stub network access links. In this paper, we explore the benefits of deploying packet-level redundant content elimination as a universal primitive on all Internet routers. Such a universal deployment would immediately reduce link loads everywhere. However, we argue that far more significant network-wide benefits can be derived by redesigning network routing protocols to leverage the universal deployment. We develop "redundancy-aware" intra- and inter-domain routing algorithms and show that they enable better traffic engineering, reduce link usage costs, and enhance ISPs' responsiveness to traffic variations. In particular, employing redundancy elimination approaches across redundancy-aware routes can lower intra and inter-domain link loads by 10-50%. We also address key challenges that may hinder implementation of redundancy elimination on fast routers. Our current software router implementation can run at OC48 speeds.

230 citations


Journal ArticleDOI
TL;DR: A novel selection strategy based on the concept of Neighbors-on-Path is presented that can be coupled with any adaptive routing algorithm to exploit the situations of indecision occurring when the routing function returns several admissible output channels.
Abstract: Efficient and deadlock-free routing is critical to the performance of networks-on-chip. The effectiveness of any adaptive routing algorithm strongly depends on the underlying selection strategy. A selection function is used to select the output channel where the packet will be forwarded on. In this paper we present a novel selection strategy that can be coupled with any adaptive routing algorithm. The proposed selection strategy is based on the concept of Neighbors-on-Path the aims of which is to exploit the situations of indecision occurring when the routing function returns several admissible output channels. The overall objective is to choose the channel that will allow the packet to be routed to its destination along a path that is as free as possible of congested nodes. Performance evaluation is carried out by using a flit-accurate simulator under traffic scenarios generated by both synthetic and real applications. Results obtained show how the proposed selection strategy applied to the Odd-Even routing algorithm yields an improvement in both average delay and saturation point up to 20% and 30% on average respectively, with a minimal overhead in terms of area occupation. In addition, a positive effect on total energy consumption is also observed under near-congestion packet injection rates.

226 citations


Patent
27 Oct 2008
TL;DR: In this article, the authors propose a method and apparatus for interdomain routing of calls in a network, where the network represents a first wide area network, and each of the adjacent nodes inserts an entry in its own routing table associating access to the range of addresses in the second-wide area network with the network address of the routing node and the cost for access.
Abstract: A method and apparatus for inter-domain routing of calls in a network, where the network represents a first wide area network. A routing node of the network advertises its access to a range of addresses in a second wide area network and a cost for access to the range of addresses to all adjacent nodes in the network. Each of the adjacent nodes inserts an entry in its own routing table associating access to the range of addresses in the second wide area network with the network address of the routing node and the cost for access. Each adjacent node then modifies the cost for access by adding its own cost and advertises its access to the range of addresses in the second wide area network and the modified cost for access to all of its adjacent nodes. When a call addressed to a destination address in the range of address in the second wide area network is received at each node of the network, then the node searches for the entry in its routing table corresponding to the range of addresses in the second wide area network having the lowest cost for access and connects the call to the adjacent node associated with the entry having the lowest cost. The routing node can also advertise one or more protocol types which it can support, where the protocol types are associated with the routing node in the routing table in each adjacent node and a call having a given protocol type is also routed at each node of the network based upon its protocol type.

202 citations


Patent
20 Apr 2008
TL;DR: A peer-to-peer collaboration system in which changes to a shared space may be broadcast to all of the peers in a collaboration session using messages sent with a combination of addressing techniques is described in this article.
Abstract: A peer-to-peer collaboration system in which changes to a shared space may be broadcast to all of the peers in a collaboration session using messages sent with a combination of addressing techniques. Messages may be addressed for direct peer-to-peer transmission, indirect transmission through another peer or indirect transmission through a server. The type of addressing used to communicate with each peer is determined through the use of a routing table. The routing table defines interconnected groups of peers and may be used to select one or more peers in each group as the initial recipients of the message. The initial recipients may forward the message to other peers within their groups, such that all peers receive the message. For peers behind a NAT, one or more NAT traversal techniques may be used to obtain information to construct the routing table.

187 citations


Patent
Van L. Jacobson1, Diana K. Smetters1
18 Dec 2008
TL;DR: In this paper, the authors present a system for controlling the spread of interests and content in a content centric network (CCN), which maintains a routing policy for content data and receives a packet associated with a piece of content or an interest for the content.
Abstract: One embodiment of the present invention provides a system for controlling the spread of interests and content in a content centric network (CCN). During operation, the system maintains a routing policy for content data. The system also receives a packet associated with a piece of content or an interest for the content. Next, the system determines that the structured name included in the packet is within the namespace specified in the routing policy. The system further determines that the packet satisfies the condition in the routing policy. Subsequently, the system routes the packet based on in part the action corresponding to the condition as specified in the routing policy.

185 citations


Patent
25 Nov 2008
TL;DR: In this paper, the authors present a routing management system for VoIP calls in a Voice over Internet Protocol (VoIP) system, which includes a routing manager which maintains a list of local routes, establishes and manages connections to the routing server, exports routes to the Routing Server, imports disseminated routes from the routing Server, caches those routes for future use, finds all matching routes for a particular number dialed by the user and prioritizes those routes based on timing, access and ordering information.
Abstract: A method, system, and computer program product for routing network traffic (calls in a Voice over Internet Protocol (VoIP)), which expands the capabilities of existing systems by providing faster and more efficient direction of network traffic, is disclosed. A routing management system includes a routing manager which maintains a list of local routes, establishes and manages connections to the routing server(s), exports routes to the routing server(s), imports disseminated routes from the routing server(s), obtains static global and dynamic routes from the routing server(s), caches those routes for future use, finds all matching routes for a particular number dialed by the user, and prioritizing those routes based on timing, access and ordering information. An additional embodiment contains at least one routing server which provides look-up services for gateway server(s), allows export of local routes from gateway server(s), and distributes translation data; and at least one gateway server which handles calls received on either the Internet protocol (IP) or traditional telephony networks. The gateway server bridges calls between the different kinds of networks, interacts with users, interfaces with the routing system.

168 citations


Journal ArticleDOI
TL;DR: This paper presents the taxonomy of the multicast routing protocols, their properties and design features, and aims to aid MANETs researchers and application developers in selecting appropriate multicasts routing protocols for their work.

Journal ArticleDOI
TL;DR: An algorithmic model for wireless ad hoc and sensor networks that aims to be sufficiently close to reality as to represent practical realworld networks while at the same time being concise enough to promote strong theoretical results is studied.
Abstract: In this paper, we study an algorithmic model for wireless ad hoc and sensor networks that aims to be sufficiently close to reality as to represent practical real-world networks while at the same time being concise enough to promote strong theoretical results The quasi unit disk graph model contains all edges shorter than a parameter d between 0 and 1 and no edges longer than 1 We show that--in comparison to the cost known for unit disk graphs--the complexity results of geographic routing in this model contain the additional factor 1/d2 We prove that in quasi unit disk graphs flooding is an asymptotically message-optimal routing technique, we provide a geographic routing algorithm being most efficient in dense networks, and we show that classic geographic routing is possible with the same asymptotic performance guarantees as for unit disk graphs if d ≥ 1/√2

Patent
01 Jul 2008
TL;DR: In this article, the authors propose a method for analyzing traffic in a communications network that includes sampling data packets at a plurality of network interconnection points and aggregating the sampled packet data in a neutral format from the plurality of interconnection nodes.
Abstract: A method for analyzing traffic in a communications network includes sampling data packets at a plurality of network interconnection points, wherein sampling the data packets includes generating a plurality of sampled packet data in one or more standardized formats, converting the sampled packet data from the one or more standardized formats into a neutral format, and aggregating the sampled packet data in the neutral format from the plurality of network interconnection points. A system includes a communications node operable to sample data packets flowing through and generate sample packet data in a specified format, a collector node operable to convert the sampled packet data into a neutral format, the collector node further operable to map IP addresses of the sampled packet data to corresponding prefixes in a routing table; and an aggregator node operable to aggregate neutrally formatted sampled packet data from a plurality of collector nodes.

Proceedings ArticleDOI
13 Apr 2008
TL;DR: This work provides important guidelines for designing routing metrics and identifies the specific properties that a routing metric must have in order to be combined with certain type of routing protocols.
Abstract: The design of a routing protocol must be based on the characteristics of its target networks. The diversity of wireless networks motivates the design of different routing metrics, capturing different aspects of wireless communications. The design of routing metrics, however, is not arbitrary since it has a great impact on the proper operation of routing protocols. Combining a wrong type of routing metrics with a routing protocol may result in routing loops and suboptimal paths. In this paper, we thoroughly study the relationship between routing metrics and routing protocols. Our work provides important guidelines for designing routing metrics and identifies the specific properties that a routing metric must have in order to be combined with certain type of routing protocols.

Journal ArticleDOI
TL;DR: Simulations show that the improved FEC and CNHA/CWA schemes outperform the most recent O(log2|T|) schemes in terms of lookup time, update time, and memory requirement.
Abstract: Dynamic IP router table schemes, which have recently been proposed in the literature, perform an IP lookup or an online prefix update in O(log2|T|) memory accesses (MAs). In terms of lookup time, they are still slower than the full expansion/compression (FEC) scheme (compressed next-hop array/code word array (CNHA/CWA)), which requires exactly (at most) three MAs, irrespective of the number of prefixes |T| in a routing table T. The prefix updates in both FEC and CNHA/CWA have a drawback: Inefficient offline structure reconstruction is arguably the only viable solution. This paper solves the problem. We propose the use of lexicographic ordered prefixes to reduce the offline construction time of both schemes. Simulations on several real routing databases, run on the same platform, show that our approach constructs FEC (CNHA/CWA) tables in 2.68 to 7.54 (4.57 to 6) times faster than that from previous techniques. We also propose an online update scheme that, using an updatable address set and selectively decompressing the FEC and CNHA/CWA structures, modifies only the next hops of the addresses in the set. Recompressing the updated structures, the resulting forwarding tables are identical to those obtained by structure reconstructions, but are obtained at much lower computational cost. Our simulations show that the improved FEC and CNHA/CWA outperform the most recent O(log2|T|) schemes in terms of lookup time, update time, and memory requirement.

Proceedings Article
16 Apr 2008
TL;DR: A fitted bed sheet and a method of making the sheet from a rectangular blank of sheet material are disclosed.
Abstract: Internet routing protocols (BGP, OSPF, RIP) have traditionally favored responsiveness over consistency. A router applies a received update immediately to its forwarding table before propagating the update to other routers, including those that potentially depend upon the outcome of the update. Responsiveness comes at the cost of routing loops and blackholes--a router A thinks its route to a destination is via B but B disagrees. By favoring responsiveness (a liveness property) over consistency (a safety property), Internet routing has lost both. Our position is that consistent state in a distributed system makes its behavior more predictable and securable. To this end, we present consensus routing, a consistency-first approach that cleanly separates safety and liveness using two logically distinct modes of packet delivery: a stable mode where a route is adopted only after all dependent routers have agreed upon it, and a transient mode that heuristically forwards the small fraction of packets that encounter failed links. Somewhat surprisingly, we find that consensus routing improves overall availability when used in conjunction with existing transient mode heuristics such as backup paths, deflections, or detouring. Experiments on the Internet's AS-level topology show that consensus routing eliminates nearly all transient disconnectivity in BGP.

Journal ArticleDOI
TL;DR: The decomposition is demonstrated by implementing an overlay construction toolkit Overlay Weaver, which is the first feasibility proof of the layered model by supporting multiple algorithms and the higher-level services and the resulting algorithm implementations work on a real TCP/IP network as it is.

Proceedings ArticleDOI
13 Apr 2008
TL;DR: It is shown that a cubic routing stretch constitutes a lower bound for any local memoryless routing algorithm, and several randomized geographic routing algorithms which work well for 3D network topologies are proposed and analyzed.
Abstract: We reconsider the problem of geographic routing in wireless ad hoc networks. We are interested in local, memoryless routing algorithms, i.e. each network node bases its routing decision solely on its local view of the network, nodes do not store any message state, and the message itself can only carry information about O(1) nodes. In geographic routing schemes, each network node is assumed to know the coordinates of itself and all adjacent nodes, and each message carries the coordinates of its target. Whereas many of the aspects of geographic routing have already been solved for 2D networks, little is known about higher-dimensional networks. It has been shown only recently that there is in fact no local memoryless routing algorithm for 3D networks that delivers messages deterministically. In this paper, we show that a cubic routing stretch constitutes a lower bound for any local memoryless routing algorithm, and propose and analyze several randomized geographic routing algorithms which work well for 3D network topologies. For unit ball graphs, we present a technique to locally capture the surface of holes in the network, which leads to 3D routing algorithms similar to the greedy-face-greedy approach for 2D networks.

Journal ArticleDOI
TL;DR: This paper considers (p, q )-Epidemic Routing, a class of store-carry-forward routing schemes, for sparsely populated mobile ad hoc networks, taking account of the recovery process that deletes unnecessary packets from the network.
Abstract: This paper considers (p, q )-Epidemic Routing, a class of store-carry-forward routing schemes, for sparsely populated mobile ad hoc networks. Our forwarding scheme includes Two-Hop Forwarding and the conventional Epidemic Routing as special cases. In such forwarding schemes, the original packet is copied many times and its packet copies spread over the network. Therefore those packet copies should be deleted after a packet reaches the destination. We analyze the performance of (p, q)-Epidemic Routing with VACCINE recovery scheme. Unlike most of the existing studies, we discuss the performance of (p, q)-Epidemic Routing in depth, taking account of the recovery process that deletes unnecessary packets from the network.

Patent
15 Dec 2008
TL;DR: In this article, a system and method for routing an incoming call to a subscriber-selected destination number in accordance with dynamic data concerning the subscriber provided by an address book, a calendar and a presence server is presented.
Abstract: A system and method for routing an incoming call to a subscriber-selected destination number in accordance with dynamic data concerning the subscriber provided by an address book, a calendar and a presence server. A routing system routes the incoming call in accordance with a subscriber-defined routing rule associated with the originating number of the incoming call, as determined from the address book. The routing rule may specify that the incoming call be routed to a destination number associated with the current date and time, as indicated by the calendar. The routing rule may specify, alternatively or in addition thereto, that the incoming call be routed to a destination number associated with a presence-enabled service on which the subscriber is currently active. The subscriber or caller may also be alternatively notified of the routing of the incoming call.

Proceedings ArticleDOI
09 Dec 2008
TL;DR: LISP-DHT is designed to take full advantage of the DHT architecture in order to build an efficient and secured mapping lookup system while preserving the locality of the mapping.
Abstract: Recent activities in the IRTF (Internet Research Task Force), and in particular in the Routing Research Group (RRG), focus on defining a new Internet architecture, in order to solve scalability issues related to interdomain routing. The research community has agreed that the separation of the end-systems' addressing space (the identifiers) and the routing locators' space will alleviate the routing burden of the Default Free Zone. Nevertheless, such approach, adding a new level of indirection, implies the need of storing and distributing mappings between identifiers and routing locators. In this paper we present LISP-DHT, a mapping distribution system based on Distributed Hash Tables (DHTs). LISP-DHT is designed to take full advantage of the DHT architecture in order to build an efficient and secured mapping lookup system while preserving the locality of the mapping. The paper describes the overall architecture of LISP-DHT, explaining its main points and how it works.

Journal ArticleDOI
TL;DR: This paper contains an introduction to the problem field of geographic routing, a specific routing algorithm based on a synthesis of the greedy forwarding and face routing approaches, and an algorithmic analysis of the presented algorithm from both a worst-case and an average-case perspective.
Abstract: The one type of routing in ad hoc and sensor networks that currently appears to be most amenable to algorithmic analysis is geographic routing. This paper contains an introduction to the problem field of geographic routing, presents a specific routing algorithm based on a synthesis of the greedy forwarding and face routing approaches, and provides an algorithmic analysis of the presented algorithm from both a worst-case and an average-case perspective.

Journal Article
Wei Gang1
TL;DR: The problems and challenges of routing protocols are presented by the analysis and comparison of typical flat and hierarchical routing protocols and the important features that ideal routing protocols possess are summarized.
Abstract: This paper presented the problems and challenges of routing protocols by the analysis and comparison of typical flat and hierarchical routing protocols.Finally,summaried the important features that ideal routing protocols possess as well as its future research strategies and trends.

Journal ArticleDOI
TL;DR: This work proposes a single copy and multi-hop opportunistic routing scheme for sparse delay tolerant networks (DTNs) that aims at minimizing delivery time in case of independent exponential pairwise inter-contacts.
Abstract: We propose in this work a single copy and multi-hop opportunistic routing scheme for sparse delay tolerant networks (DTNs). The scheme uses as only input the estimates of the average inter-contact times between the nodes in the network. Defined as the fixed point of a recursive process, it aims at minimizing delivery time in case of independent exponential pairwise inter-contacts. The two properties of loop-free forwarding and polynomial convergence make the scheme workable for routing in DTNs. The routing performances of the scheme are evaluated on three publicly available reference data sets. Comparisons with well known single-copy schemes, including MED and the two hop relay strategy, consistently demonstrate improvements for both delivery ratio and delay.

Patent
15 Feb 2008
TL;DR: In this article, a rules engine evaluates its policies on a state change (e.g., network availability, time of day, etc.) to configure a routing table and, together with communication APIs, provides an appropriate connection to an application for its respective communications.
Abstract: Communication devices capable of at least two communication modes (e.g. WLAN, WMAN and WWAN and/or wired modes) can be configured to optimize communications using a policy-based mechanism to configure connections and routes. A rules engine evaluates its policies on a state change (e.g. network availability, time of day, etc.) to configure a routing table and, together with communication APIs, provides an appropriate connection to an application for its respective communications. Policies may be responsive to various factors such as Radio Access Technology (high/low bandwidth), cost, presence, time of day, location, application type and quality of service (QoS) requirements among others to optimize communications.

Journal ArticleDOI
TL;DR: A novel real-time routing protocol with load distribution (RTLD) that ensures high packet throughput with minimized packet overhead and prolongs the lifetime of WSN.

Journal ArticleDOI
Michael D. Moffitt1
TL;DR: MaizeRouter reflects a significant leap in progress over existing publicly available routing tools yet relies upon relatively simple operations, includingextreme edge shifting, a technique aimed primarily at the efficient reduction of routing congestion, and edge retraction, a counterpart to extreme edge shifting that serves to reduce unnecessary wirelength.
Abstract: In this paper, we present the complete design and architectural details of MaizeRouter. MaizeRouter reflects a significant leap in progress over existing publicly available routing tools yet relies upon relatively simple operations, including extreme edge shifting, a technique aimed primarily at the efficient reduction of routing congestion, and edge retraction, a counterpart to extreme edge shifting that serves to reduce unnecessary wirelength. We present enhanced variations of these operations to enable the rapid exploration of candidate paths, along with a form of dynamic cost deflation that provides our various path computation procedures with progressively more accurate (and less optimistic) cost information as search continues. These algorithmic contributions are built upon a framework of interdependent net decomposition, a representation that improves upon traditional two-pin net decomposition by preventing duplication of routing resources while enabling cheap and incremental topological reconstruction. Collectively, these operations permit a broad search space that previous algorithms have been unable to achieve, resulting in solutions of considerably higher quality than those of well-established routers.

Proceedings ArticleDOI
13 Apr 2008
TL;DR: A parallel SRAM-based multi- pipeline architecture for terabit IP lookup, with a two-level mapping scheme, that can store a core routing table with over 200 K unique routing prefixes using 3.5 MB of memory.
Abstract: Continuous growth in network link rates poses a strong demand on high speed IP lookup engines. While Ternary Content Addressable Memory (TCAM) based solutions serve most of today's high-end routers, they do not scale well for the next-generation. On the other hand, pipelined SRAM- based algorithmic solutions become attractive. Intuitively multiple pipelines can be utilized in parallel to have a multiplicative effect on the throughput. However, several challenges must be addressed for such solutions to realize high throughput. First, the memory distribution across different stages of each pipeline as well as across different pipelines must be balanced. Second, the traffic on various pipelines should be balanced. In this paper, we propose a parallel SRAM-based multi- pipeline architecture for terabit IP lookup. To balance the memory requirement over the stages, a two-level mapping scheme is presented. By trie partitioning and subtrie-to-pipeline mapping, we ensure that each pipeline contains approximately equal number of trie nodes. Then, within each pipeline, a fine-grained node-to-stage mapping is used to achieve evenly distributed memory across the stages. To balance the traffic on different pipelines, both pipelined prefix caching and dynamic subtrie-to-pipeline remapping are employed. Simulation using real-life data shows that the proposed architecture with 8 pipelines can store a core routing table with over 200 K unique routing prefixes using 3.5 MB of memory. It achieves a throughput of up to 3.2 billion packets per second, i.e. 1 Tbps for minimum size (40 bytes) packets.

Journal ArticleDOI
TL;DR: In this article, the authors study the performance of a wide array of forwarding strategies, via analysis, extensive simulations and a set of experiments on motes, and find that the product of packet reception rate and the distance improvement towards destination (PRR × d) is a highly suitable metric for geographic forwarding in realistic environments.
Abstract: Recent experimental studies have shown that wireless links in real sensor networks can be extremely unreliable, deviating to a large extent from the idealized perfect-reception-within-range models used in common network simulation tools. Previously proposed geographic routing protocols commonly employ a maximum-distance greedy forwarding technique that works well in ideal conditions. However, such a forwarding technique performs poorly in realistic conditions as it tends to forward packets on lossy links. Based on a recently developed link loss model, we study the performance of a wide array of forwarding strategies, via analysis, extensive simulations and a set of experiments on motes. We find that the product of the packet reception rate and the distance improvement towards destination (PRR × d) is a highly suitable metric for geographic forwarding in realistic environments.

Proceedings ArticleDOI
08 Nov 2008
TL;DR: In this paper, the authors propose bLBDR, an efficient multicast and broadcast mechanism built on top of LBDR, which performs multicast operations using a logic-based broadcast within a domain (a region with bounds).
Abstract: Beyond a certain number of cores, multi-core processing chips will require a network-on-chip (NoC) to interconnect the cores and overcome the limitations of a bus. NoCs must be carefully designed to meet constraints like power consumption, area, and ultra low latencies. Although 2D meshes with DOR (dimension-order-routing) meet these constraints, the need for partitioning (e.g. virtual machines, coherency domains) and traffic isolation may prevent the use of DOR routing. Also, core heterogeneity and manufacturing and run-time faults may lead to partially irregular topologies. Routing in these topologies is complex, and previously proposed solutions required routing tables, which drastically increase power consumption, area, and latency. The exception is LBDR (logic-based distributed routing), a flexible routing method for irregular topologies that removes the need for using routing tables (both at end-nodes and switches), thus achieving large savings in chip area and power consumption. But LBDR lacks support for multicast and broadcast, which are required to efficiently support cache coherence protocols both for single and multiple coherence domains. In this paper we propose bLBDR, an efficient multicast and broadcast mechanism built on top of LBDR. bLBDR performs multicast operations using a logic-based broadcast within a domain (a region with bounds). This allows us to isolate the traffic into different domains, thus enabling the concept of visualization at the NoC level. Also, bLBDR extends the concept of routing regions in LBDR by providing a mechanism that allows the flexible definition of multiple domains, sets of network resources. bLBDR fulfills all the practical requirements, including not only low latency and power and area efficiency, but also support for visualization, partitionability, fault-tolerance, traffic isolation and broadcast across the entire network as well as constrained to coherency domains or regions. All this is achieved by a small and power efficient routing logic (7times area savings and 17times power reduction when compared to a routing table in an 8 times 8 mesh network).