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Showing papers on "Static routing published in 1994"


Proceedings ArticleDOI
01 Oct 1994
TL;DR: The modifications address some of the previous objections to the use of Bellman-Ford, related to the poor looping properties of such algorithms in the face of broken links and the resulting time dependent nature of the interconnection topology describing the links between the Mobile hosts.
Abstract: An ad-hoc network is the cooperative engagement of a collection of Mobile Hosts without the required intervention of any centralized Access Point. In this paper we present an innovative design for the operation of such ad-hoc networks. The basic idea of the design is to operate each Mobile Host as a specialized router, which periodically advertises its view of the interconnection topology with other Mobile Hosts within the network. This amounts to a new sort of routing protocol. We have investigated modifications to the basic Bellman-Ford routing mechanisms, as specified by RIP [5], to make it suitable for a dynamic and self-starting network mechanism as is required by users wishing to utilize ad hoc networks. Our modifications address some of the previous objections to the use of Bellman-Ford, related to the poor looping properties of such algorithms in the face of broken links and the resulting time dependent nature of the interconnection topology describing the links between the Mobile Hosts. Finally, we describe the ways in which the basic network-layer routing can be modified to provide MAC-layer support for ad-hoc networks.

6,877 citations


Journal ArticleDOI
TL;DR: This work shows that the vehicle routing problem can be modeled as the problem of finding a minimum cost K-tree with two K edges incident on the depot and subject to some side constraints that impose vehicle capacity and the requirement that each customer be visited exactly once.
Abstract: We consider the problem of optimally scheduling a fleet of K vehicles to make deliveries to n customers subject to vehicle capacity constraints. Given a graph with n + 1 nodes, a K-tree is defined to be a set of n + K edges that span the graph. We show that the vehicle routing problem can be modeled as the problem of finding a minimum cost K-tree with two K edges incident on the depot and subject to some side constraints that impose vehicle capacity and the requirement that each customer be visited exactly once. The side constraints are dualized to obtain a Lagrangian problem that provides lower bounds in a branch-and-bound algorithm. This algorithm has produced proven optimal solutions for a number of difficult problems, including a well-known problem with 100 customers and several real problems with 25–71 customers.

521 citations


Patent
Charles E. Perkins1
07 Dec 1994
TL;DR: In this paper, a decision is made to delay advertising routes which are about to change soon, thus damping oscillations of the route tables, in order to damp out oscillations, data is kept about how often the routes change.
Abstract: Packets are transmitted between stations of an ad-hoc network of mobile stations by using routing tables which are stored at each station of the network. Routing information is broadcast or multicast according to three schedules; upon demand to show new routes, periodically to show recently changed routes, and less often to provide a complete dump of all known routes. A new route will trigger immediate re-broadcast so that this information is quickly disseminated. A new route is defined to be one with a better metric or a metric of infinity. A metric of infinity indicates a broken link; i.e., a particular destination is no longer reachable and thus all other destinations depending upon the newly unreachable destination are themselves unreachable. Periodically, routes are advertised. This advertisement serves primarily in most cases to notify all neighbors that everything they have stored is still correct regarding the broadcasting Mobile Host. On rarer occasions when the routing topology changes, the demand nature of the incremental update displaces the periodic transmission until an update interval transpires. In order to damp out oscillations, data is kept about how often the routes change. Based on this data, a decision may be made to delay advertising routes which are about to change soon, thus damping oscillations of the route tables.

498 citations


Proceedings ArticleDOI
01 Oct 1994
TL;DR: The Protocol Independent Multicast (PIM) architecture maintains the traditional IP multicast service model of receiver-initiated membership and uses soft-state mechanisms to adapt to underlying network conditions and group dynamics, which make it well suited to large heterogeneous inter-networks.
Abstract: Existing multicast routing mechanisms were intended for use within regions where a group is widely represented or bandwidth is universally plentiful. When group members, and senders to those group members, are distributed sparsely across a wide area, these schemes are not efficient; data packets or membership report information are occasionally sent over many links that do not lead to receivers or senders, respectively. We have developed a multicast routing architecture that efficiently establishes distribution trees across wide area internets, where many groups will be sparsely represented. Efficiency is measured in terms of the state, control message processing, and data packet processing, required across the entire network in order to deliver data packets to the members of the group.Our Protocol Independent Multicast (PIM) architecture: (a) maintains the traditional IP multicast service model of receiver-initiated membership; (b) can be configured to adapt to different multicast group and network characteristics; (c) is not dependent on a specific unicast routing protocol; and (d) uses soft-state mechanisms to adapt to underlying network conditions and group dynamics. The robustness, flexibility, and scaling properties of this architecture make it well suited to large heterogeneous inter-networks.

394 citations


Journal ArticleDOI
TL;DR: This paper presents a model for designing wormhole routing algorithms based on analyzing the directions in which packets can turn in a network and the cycles that the turns can form, which produces routing algorithms that are deadlock free, livelockfree, minimal or nonminimal, and highly adaptive.
Abstract: This paper presents a model for designing wormhole routing algorithms. A unique feature of the model is that it is not based on adding physical or virtual channels to direct networks (although it can be applied to networks with extra channels). Instead, the model is based on analyzing the directions in which packets can turn in a network and the cycles that the turns can form. Prohibiting just enough turns to break all of the cycles produces routing algorithms that are deadlock free, livelock free, minimal or nonminimal, and highly adaptive. This paper focuses on the two most common network topologies for wormhole routing, n-dimensional meshes and k-ary n-cubes without extra channels

385 citations


Journal ArticleDOI
TL;DR: It is proved that there exists a schedule for routing any set of packets with edge-simple paths, on any network, inO(c+d) steps, wherec is the congestion of the paths in the network, andd is the length of the longest path.
Abstract: In this paper, we prove that there exists a schedule for routing any set of packets with edge-simple paths, on any network, inO(c+d) steps, wherec is the congestion of the paths in the network, andd is the length of the longest path. The result has applications to packet routing in parallel machines, network emulations, and job-shop scheduling.

344 citations


Journal ArticleDOI
TL;DR: These are the first deadlock-free multicast wormhole routing algorithms ever proposed and studied and indicate that a dual-path routing algorithm offers performance advantages over tree-based, multipath, and fixed-path algorithms.
Abstract: Multicast communication services, in which the same message is delivered from a source node to an arbitrary number of destination nodes, are being provided in new-generation multicomputers. Broadcast is a special case of multicast in which a message is delivered to all nodes in the network. The nCUBE-2, a wormhole-routed hypercube multicomputer, provides hardware support for broadcast and a restricted form of multicast in which the destinations form a subcube. However, the broadcast routing algorithm adopted in the nCUBE-2 is not deadlock-free. In this paper, four multicast wormhole routing strategies for 2-D mesh multicomputers are proposed and studied. All of the algorithms are shown to be deadlock-free. These are the first deadlock-free multicast wormhole routing algorithms ever proposed. A simulation study has been conducted that compares the performance of these multicast algorithms under dynamic network traffic conditions in a 2-D mesh. The results indicate that a dual-path routing algorithm offers performance advantages over tree-based, multipath, and fixed-path algorithms. >

287 citations


Journal ArticleDOI
TL;DR: The authors study the synchronization of periodic routing messages, and offer guidelines on how to avoid inadvertent synchronization, and show that synchronization can be avoided by the addition of randomization to the traffic sources and quantify how much randomization is necessary.
Abstract: The paper considers a network with many apparently-independent periodic processes and discusses one method by which these processes can inadvertently become synchronized. In particular, the authors study the synchronization of periodic routing messages, and offer guidelines on how to avoid inadvertent synchronization. Using simulations and analysis, they study the process of synchronization and show that the transition from unsynchronized to synchronized traffic is not one of gradual degradation but is instead a very abrupt 'phase transition': in general, the addition of a single router will convert a completely unsynchronized traffic stream into a completely synchronized one. They show that synchronization can be avoided by the addition of randomization to the traffic sources and quantify how much randomization is necessary. In addition, they argue that the inadvertent synchronization of periodic processes is likely to become an increasing problem in computer networks. >

265 citations


Proceedings ArticleDOI
15 Aug 1994
TL;DR: A partially adaptive routing algorithm for k-ary n-cubes which doubles the throughput without increasing the hardware complexity significantly and is the key for the design of maximally adaptive routing algorithms with minimum restrictions.
Abstract: Deadlock avoidance is a key issue in wormhole networks. A first approach [8] consists of removing the cyclic dependencies between channels. Although this is a necessary and sufficient condition for deadlock-free deterministic routing, it is only a sufficient condition for deadlock-free adaptive routing. A more powerful approach [12] only requires the absence of cyclic dependencies on a connected channel subset. The remaining channels can be used in almost any way. In this paper, we propose a necessary and sufficient condition for deadlock-free adaptive routing. This condition is the key for the design of maximally adaptive routing algorithms with minimum restrictions. Some examples are given, showing the application of the new theory. In particular, we propose a partially adaptive routing algorithm for k-ary n-cubes which doubles the throughput without increasing the hardware complexity significantly.

215 citations


Journal ArticleDOI
TL;DR: In this paper, the authors developed detailed analytical performance models for k-ary n-cube networks with single-hit or infinite buffers, wormhole routing, and the nonadaptive deadlock-free routing scheme proposed by Dally and Seitz (1987).
Abstract: This paper develops detailed analytical performance models for k-ary n-cube networks with single-hit or infinite buffers, wormhole routing, and the nonadaptive deadlock-free routing scheme proposed by Dally and Seitz (1987). In contrast to previous performance studies of such networks, the system is modeled as a closed queueing network that: includes the effects of blocking and pipelining of messages in the network; allows for arbitrary source-destination probability distributions; and explicitly models the virtual channels used in the deadlock-free routing algorithm. The models are used to examine several performance issues for 2-D networks with shared-memory traffic. These results should prove useful for engineering high-performance systems based on low-dimensional k-ary n-cube networks. >

148 citations


Book
01 Jun 1994
TL;DR: In this article, the concept of virtual channels is extended to multiple virtual communication systems that provide adaptability and fault tolerance in addition to being deadlock-free, and a channel dependency graph is taken as the definition of what connections are possible, and any routing function must use only those connections defined by it.
Abstract: The concept of virtual channels is extended to multiple virtual communication systems that provide adaptability and fault tolerance in addition to being deadlock-free. A channel dependency graph is taken as the definition of what connections are possible, and any routing function must use only those connections defined by it. Virtual interconnection networks allowing adaptive, deadlock-free routing are examined for three k-ary n-cube topologies: unidirectional, torus-connected bidirectional, and mesh-connected bidirectional. >

Journal ArticleDOI
TL;DR: Four worm-hole routing techniques for the two-dimensional torus are experimentally evaluated using a dynamic message injection model and different traffic patterns and message lengths.
Abstract: This paper consists of two parts. In the first part, two new algorithms for deadlock- and livelock-free wormhole routing in the torus network are presented. The first algorithm, called Channels, is for the n-dimensional torus network. This technique is fully-adaptive minimal, that is, all paths with a minimal number of hops from source to destination are available for routing, and needs only five virtual channels per bidirectional link, the lowest channel requirement known in the literature for fully-adaptive minimal worm-hole routing. In addition, this result also yields the lowest buffer requirement known in the literature for packet-switched fully-adaptive minimal routing. The second algorithm, called 4-Classes, is for the bidimensional torus network. This technique is fully-adaptive minimal and requires only eight virtual channels per bidirectional link. Also, it allows for a highly parallel implementation of its associated routing node. In the second part of this paper, four worm-hole routing techniques for the two-dimensional torus are experimentally evaluated using a dynamic message injection model and different traffic patterns and message lengths. >

Journal ArticleDOI
TL;DR: An analytical model is presented for the performance evaluation of hypercube computers aimed at modeling a deadlock-free wormhole routing scheme prevalent on second generation hypercube systems and extended to virtual cut-through routing and random wormholes routing techniques.
Abstract: We present an analytical model for the performance evaluation of hypercube computers. This analysis is aimed at modeling a deadlock-free wormhole routing scheme prevalent on second generation hypercube systems. Probability of blocking and average message delay are the two performance measures discussed. We start with the communication traffic to find the probability of blocking. The traffic analysis can capture any message destination distribution. Next, we find the average message delay that consists of two parts. The first part is the actual message transfer delay between any source and destination nodes. The second part of the delay is due to blocking caused by the wormhole routing scheme. The analysis is also extended to virtual cut-through routing and random wormhole routing techniques. The validity of the model is demonstrated by comparing analytical results with those from simulation. >

Proceedings ArticleDOI
20 Nov 1994
TL;DR: The paper describes both upper and lower bounds on the competitive ratio of algorithms for admission control and virtual circuit routing in trees, arrays, and hypercubes (the networks most commonly used in conjunction with nigh performance computing and communication).
Abstract: This paper considers the problems of admission control and virtual circuit routing in high performance computing and communication systems. Admission control and virtual circuit routing problems arise in numerous applications, including video-servers, real-lime database servers, and the provision of permanent virtual channel in large-scale communications networks. The paper describes both upper and lower bounds on the competitive ratio of algorithms for admission control and virtual circuit routing in trees, arrays, and hypercubes (the networks most commonly used in conjunction with nigh performance computing and communication). Our results include optimal algorithms for admission control and virtual circuit routing in trees, as well as the first competitive algorithms for these problems on non-tree networks. A key result of our research is the development of on-line algorithms that substantially outperform the greedy-based approaches that are used in practice. >

Patent
31 May 1994
TL;DR: In this paper, routing tables for each node are generated in advance by a recursive process that considers link usage and anticipated link loading for different times and states of the constellation, and the routing tables are updated regularly to reflect anticipated traffic loading and physical changes in node connectivity within the constellation which occur as a result of satellite motion.
Abstract: Information packets are routed among a constellation of satellite nodes in a communication system in a distributed, yet systematic fashion. Routing tables for each node are generated in advance by a recursive process that considers link usage and anticipated link loading for different times and states of the constellation. Routing tables are generated centrally, distributed to, and maintained in each satellite node. The routing tables are updated regularly to reflect anticipated traffic loading and physical changes in node connectivity within the constellation which occur as a result of satellite motion. The tables are also updated responsively to reflect changes in network connectivity which occur because of failures that may occur in the cross-links or satellite nodes.

Proceedings ArticleDOI
01 Apr 1994
TL;DR: The advantages of CR and FCR not only simplify hardware support for adaptive routing and fault-tolerance, they also can simplify communication software layers.
Abstract: Compressionless Routing (GR) is a new adaptive routing framework which provides a unified framework for efficient deadlock-free adaptive routing and fault-tolerance. CR exploits the tight-coupling between wormhole routers for flow control to detect potential deadlock situations and recover from them. Fault-tolerant Compressionless Routing (FCR) extends Compressionless Routing to support end-to-end fault-tolerant delivery. Detailed routing algorithms, implementation complexity and performance simulation results for CR and FCR are presented.CR has the following advantages: deadlock-free adaptive routing in torus networks with no virtual channels, simple router designs, order-preserving message transmission, applicability to a wide variety of network topologies, and elimination of the need for buffer allocation messages. FCR has the following advantages: tolerates transient faults while maintaining data integrity (nonstop fault-tolerance), tolerates permanent faults, can be applied to a wide variety of network topologies, and eliminates the need for software buffering and retry for reliability. These advantages of CR and FCR not only simplify hardware support for adaptive routing and fault-tolerance, they also can simplify communication software layers.

Patent
Akira Hashimoto1, Yuji Ito1
19 May 1994
TL;DR: In this paper, a local router comprises a protocol processor for periodically processing the routing information into a local routing information protocol (RIP) datum indicative of connection information to the LAN's connected to the local router and a comparator comparing the local RIP datum with stored information of an RIP memory.
Abstract: Connected to different routers of a packet routing network through a public network and to local area networks (LAN's) and comprising a routing table keeping routing information for an optimum path between each pair of the LAN's, a local router comprises a protocol processor for periodically processing the routing information into a local routing information protocol (RIP) datum indicative of connection information to the LAN's connected to the local router and a comparator comparing the local RIP datum with stored information of an RIP memory to discard and to write in the memory as a current datum the local RIP datum if the local RIP datum is coincident and incoincident with the stored information, respectively. A public network interface sends the current datum towards the different routers. In the routing table, the routing information is dynamically updated in response to an incoming RIP datum received from any one of the different routers.

Proceedings ArticleDOI
30 May 1994
TL;DR: This paper presents a new model for VLSI routing in the presence of obstacles, that transforms any routing instance from a geometric problem into a graph problem, and is the first model that allows computation of optimal obstacle-avoiding rectilinear Steiner trees in time corresponding to the instance size rather than the size of the routing area.
Abstract: This paper presents a new model for VLSI routing in the presence of obstacles, that transforms any routing instance from a geometric problem into a graph problem. It is the first model that allows computation of optimal obstacle-avoiding rectilinear Steiner trees in time corresponding to the instance size (the number of terminals and obstacle border segments) rather than the size of the routing area. For the most common multi-terminal critical nets-those with three or four terminals-we observe that optimal trees can be computed as efficiently as good heuristic trees, and present algorithms that do so. For nets with five or more terminals, we present algorithms that heuristically compute obstacle-avoiding Steiner trees. Analysis and experiments demonstrate that the model and algorithms work well in both theory and practice. >

Patent
Akira Hashimoto1, Hirokazu Tamiya1
22 Dec 1994
TL;DR: In this article, a desired static route is read from a static routing table and a polling is effected on a network connected to a terminal at regular intervals, if a normal response is issued from the network, then information about the above static route are entered in a routing table.
Abstract: A desired static route is read from a static routing table and a polling is effected on a network connected to a terminal at regular intervals. If a normal response is issued from the network, then information about the above static route is entered in a routing table. If no normal response is delivered from the network, then the information about the static routes entered in the routing table is deleted.

Book ChapterDOI
16 May 1994
TL;DR: This work proposed a necessary and sufficient condition for deadlock-free adaptive routing, and proposed a more powerful approach that only requires the absence of cyclic dependencies on a connected channel subset.
Abstract: Deadlock avoidance is a key issue in wormhole networks. A first approach [9] consists in removing the cyclic dependencies between channels. Although the absence of cyclic dependencies is a necessary and sufficient condition for deadlock-free deterministic routing, it is only a sufficient condition for deadlock-free adaptive routing. A more powerful approach [12] only requires the absence of cyclic dependencies on a connected channel subset. Moreover, we proposed a necessary and sufficient condition for deadlock-free adaptive routing [15].

Patent
15 Aug 1994
TL;DR: In this paper, a method and apparatus for selecting routes in a hierarchical communications network where a number of mutually isolated areas are provided at a first level, which areas are mutually linked at a second level.
Abstract: A method and apparatus for selecting routes in a hierarchical communications network wherein a number of mutually isolated areas are provided at a first level, which areas are mutually linked at a second level. In the network, routing devices are provided at both levels. For selecting a route from a first area to a second area, use is made of routing information stored in the routing devices of the first level, relating to the first level and to reaching the nearest routing device of the second level. Use is also made, in the routing devices of the first level, of routing information relating to the second level.

Proceedings ArticleDOI
21 Jun 1994
TL;DR: It is demonstrated that this adaptive routing algorithm can utilize the virtual paths (channels) between any two nodes more efficiently than any of the present algorithms with the same hardware requirement.
Abstract: An efficient fully adaptive wormhole routing algorithm for n-dimensional meshes is developed. The routing algorithm provides full adaptivity at a cost of one additional virtual channel per physical channel irrespective of the number of dimensions of the network. The algorithm is based on dividing the network graph into two acyclic graphs that contain all of the physical channels in the system. Virtual channels are classified as either waiting or nonwaiting channels. Busy channels that a message waits for to become available are classified as waiting channels, otherwise they are classified as nonwaiting channels. Thus, a message considers nonwaiting channels first to reach its destination. If all non-waiting channels are busy, the message considers waiting channels. Messages acquire waiting channels in two phases. In each phase, waiting channels belonging to one acyclic network graph are traversed. This 2-phase routing algorithm could be either minimal or nonminimal. However, we concentrate on minimal routing. It is demonstrated that this adaptive routing algorithm can utilize the virtual paths (channels) between any two nodes more efficiently than any of the present algorithms with the same hardware requirement. >

Proceedings ArticleDOI
X. Chen1, V. Kumar1
06 Jun 1994
TL;DR: The authors present a study on multicast routing algorithms for the self-routing multistage networks based on the use of the cube concept which consists of a group of outlets reachable in one pass through the network.
Abstract: The authors present a study on multicast routing algorithms for the self-routing multistage networks. This work is based on the use of the cube concept which consists of a group of outlets reachable in one pass through the network. A multicast connection is decomposed into associated cubes such that each cube can be self-routed through the network. The context of this work is a recursive scheme for multistage network where the outlets are fed back to the inlets through external links. Three routing algorithms are proposed. The emphasis is on evaluating the performance of those algorithms in terms of two metrics. Extensive results from analysis and simulations are given to derive insights into the performance of the proposed routing algorithms. >

Proceedings ArticleDOI
12 Jun 1994
TL;DR: The authors first examine two VP capacity reservation strategies, design and evaluate computationally feasible Markov decision process-based routing algorithms and show that the network blocking probability can be significantly reduced by MDP routing.
Abstract: The virtual path (VP) concept has been proposed to simplify traffic control and resource management in future B-ISDN. In particular, call setup processing can be significantly reduced when resources are reserved on VPs. However, this advantage is offset by a decrease in statistical multiplexing gains of the networks. The focus of this paper is on how to improve bandwidth efficiency through adaptive routing when capacity is reserved on all VPs. The authors first examine two VP capacity reservation strategies. They then design and evaluate computationally feasible Markov decision process-based routing algorithms and show that the network blocking probability can be significantly reduced by MDP routing. >

Proceedings ArticleDOI
12 Jun 1994
TL;DR: The authors show that the problem of optimally routing multicast streams can be formulated as an integer programming problem, and propose an efficient solution technique, composed of an extension to the decomposition principle and enhanced value-fixing rules, to prune the search space for the integer problem.
Abstract: The authors show that the problem of optimally routing multicast streams can be formulated as an integer programming problem. They propose an efficient solution technique, composed of two parts: (i) an extension to the decomposition principle, to speed up the linear relaxation of the problem, and (ii) enhanced value-fixing rules, to prune the search space for the integer problem. They characterize the reduction in run time gained using these techniques. Finally, they compare the run times for the optimum multicast routing algorithm and for existing heuristic algorithms. >

Proceedings ArticleDOI
01 Oct 1994
TL;DR: In this paper, a new family of routing algorithms for the distributed maintenance of routing information in large networks and internets is introduced, called link vector algorithms (LVA), and is based on the selective diffusion of link-state information based on a distributed computation of preferred paths, rather than on the flooding of complete link state information to all routers.
Abstract: A new family of routing algorithms for the distributed maintenance of routing information in large networks and internets is introduced. This family is called link vector algorithms (LVA), and is based on the selective diffusion of link-state information based on the distributed computation of preferred paths, rather than on the flooding of complete link-state information based on the distributed computation of preferred paths, rather than on the flooding of complete link-state information to all routers. According to LVA, each router maintains a subset of the topology that corresponds to the links used by its neighbor routers in their preferred paths to known destinations. Based on that subset of topology information, the router derives its own preferred paths and communicates the corresponding link-state information to its neighbors. An update message contains a vector of updates; each such update specifies a link and its parameters. LVAs can be used for different types of routing. The correctness of LVA is verified for arbitrary types of routing when correct and deterministic algorithms are used to select preferred paths at each router. LVA is shown to have smaller complexity than link-state and distance-vector algorithms, and to have better average performance than the ideal topology-broadcast algorithm and the distributed Bellman-Ford algorithm.

Proceedings ArticleDOI
19 Dec 1994
TL;DR: This paper analyzes the effective redundancy available in a wormhole network by combining connectivity and deadlock freedom, and proposes a sufficient condition for channel redundancy and a fault-tolerant routing algorithm for n-dimensional meshes.
Abstract: Fault-tolerant systems aim at providing continuous operations in the presence of faults. Multicomputers rely on an interconnection network between processors to support the message-passing mechanism. Therefore, the reliability of the interconnection network is very important for the reliability of the whole system. This paper analyzes the effective redundancy available in a wormhole network by combining connectivity and deadlock freedom. Redundancy is defined at the channel level. We propose a sufficient condition for channel redundancy, also computing the set of redundant channels. The redundancy level of the network is also defined, proposing a theorem that supplies its value. This theory is developed on top of our necessary and sufficient condition for deadlock-free adaptive routing. Finally, a fault-tolerant routing algorithm for n-dimensional meshes is proposed.

Patent
11 Aug 1994
TL;DR: In this paper, a network element includes a plurality of routing circuits coupled by internal communication circuitry, each routing circuit includes one or more external ports for communicating with external devices, one or multiple internal ports for communication with other routing circuits, a database for storing address and path information received via the internal and external ports and circuitry for retransmitting address information received from an external device to other of the routing circuits.
Abstract: A network element includes a plurality of routing circuits coupled by internal communication circuitry. Each routing circuit includes one or more external ports for communicating with external devices, one or more internal ports for communicating with other of the routing circuits, a database for storing address and path information received via the internal and external ports and circuitry for retransmitting address information received from an external device to other of the routing circuits.

Book
01 Jun 1994
TL;DR: In this article, simple deterministic O(log N)-step algorithms for routing permutations of packets in multibutterflies and randomly wired splitter networks are described, which are robust against faults (even in the worst case), and are efficient from a practical point of view.
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. >

Patent
19 Aug 1994
TL;DR: In this paper, the authors present a method for independently executing software components in a node of a network containing many nodes, including generating a logical hierarchy of the roles of the nodes where any node can assume one or multiple roles; and negotiating the role of nodes when there is a change in the configuration of the network.
Abstract: A method for independently executing software components in a node of a network containing many nodes. The method including generating a logical hierarchy of the roles of the nodes where any node can assume one or multiple roles; and negotiating the role of the nodes when there is a change in the configuration of the network. Another technique locates resources requested by a node in a scalable system interconnecting many nodes in a network. The technique includes identifying resources that join the network by switching from an inactive to an active state; and informing the requester the availability of the requested resource. A further technique determines routing paths in a context bridge which is able to route packets between nodes. The technique includes setting up a list of context bridges; listening for routing information packets which are periodically broadcast by other context bridges; and updating the database using the information contained in the received routing information packets. One more technique is on routing packets from a source node to a destination node using a context bridge. The technique includes determining whether the destination node has a routable protocol; if it does not have, then routing the packet using a source route containing the address of the context bridges from the source to the destination; and if it has, then routing the packet through at least one context bridge containing routable protocols.