Showing papers on "Routing table published in 1980"
TL;DR: The new ARPANET routing algorithm is an improvement over the old procedure in that it uses fewer network resources, operates on more realistic estimates of network conditions, reacts faster to important network changes, and does not suffer from long-term loops or oscillations.
Abstract: The new ARPANET routing algorithm is an improvement over the old procedure in that it uses fewer network resources, operates on more realistic estimates of network conditions, reacts faster to important network changes, and does not suffer from long-term loops or oscillations. In the new procedure, each node in the network maintains a database describing the complete network topology and the delays on all lines, and uses the database describing the network to generate a tree representing the minimum delay paths from a given root node to every other network node. Because the traffic in the network can be quite variable, each node periodically measures the delays along its outgoing lines and forwards this information to all other nodes. The delay information propagates quickly through the network so that all nodes can update their databases and continue to route traffic in a consistent and efficient manner. An extensive series of tests were conducted on the ARPANET, showing that line overhead and CPU overhead are both less than two percent, most nodes learn of an update within 100 ms, and the algorithm detects congestion and routes packets around congested areas.
787 citations
TL;DR: An opUmal algorithm to route data in a mesh-connected parallel computer is presented that uses the minimum number of unit distance routing steps for every data permutation that can be specified as above.
Abstract: An opUmal algorithm to route data in a mesh-connected parallel computer is presented This algorithm can be used to perform any data routing that can be specified by the permutation and complementing of the bits in a PE address Matrix transpose, bit reversal, vector reversal, and perfect shuffle are examples of data permutations that can be specified in this way The algorithm presented uses the minimum number of unit distance routing steps for every data permutation that can be specified as above K~EV WORDS ANY PrmASES parallel algorithm, mesh-connected computer, ILLIAC IV, permutation, complexity, data routing CR CATEGORIES 5 25, 5 31, 6 22
142 citations
Patent•
29 Oct 1980TL;DR: In this article, a routing and information system for individual motor vehicle traffic is used, in which by way of stationary routing station poles, route information and local information are transmitted to the passing vehicles.
Abstract: In a method for traffic determination, a routing and information system for individual motor vehicle traffic is used, in which by way of stationary routing station poles, route information and local information are transmitted to the passing vehicles. For the determination of the traffic situation, the traveling times between two routing station poles are measured in individual vehicles with timing units. These traveling times are transmitted, together with the local information of the first routing station pole passed by a vehicle, to the second routing station pole and are considered in determining new route recommendations.
118 citations
23 Jun 1980
TL;DR: A new routing algorithm is presented which is based on the expansion of a line in the direction perpendicular to the line, which guarantees that always a solution will be found if one exists.
Abstract: A new routing algorithm is presented which is based on the expansion of a line in the direction perpendicular to the line The line-expansion principle is first applied to the single layer routing problem For the routing on two layers only some minor modifications have to be made An important extension is added in which the search for an interconnection from a given point is initiated in more than one direction at the same time The major advantage of the line-expansion algorithm over the well-known line-search algorithm is the guarantee that always a solution will be found if one exists
48 citations
TL;DR: Four families of topologies for interconnecting many identical processors into a computer network are described and investigated with respect to bus load, routing algorithms, and the relation between the average interprocessor distance and the size of the network.
Abstract: In this paper, we describe four families of topologies for interconnecting many identical processors into a computer network. Each family extends to arbitrarily many processors while keeping the number of neighbors of any one processor fixed. These families are investigated with respect to bus load, routing algorithms, and the relation between the average interprocessor distance and the size of the network.
41 citations
IBM1
TL;DR: The results show that dynamic routing improves network performance only over a small parameter range, and should dynamic routing be used at all, it must be implemented with great care.
Abstract: This is an expanded version of an earlier report, adding, new results. The first part introduces a simple analytic model showing that dynamic routing may increase network throughput or lower delay when trunks are moderately loaded, but will reduce throughput or increase delay at heavy trunk loads. The second part of the paper presents simulation results characterizing: 1) the operation of a network "protected" by end-to-end flow control, 2) the operation of an "unprotected" network, 3) the transition between these two modes, 4) the effect of changing the update interval for the routing algorithms, 5) the effect of slow local loops, and 6) the effect of increasing the number of alternate paths available for dynamic routing. Overall, the results show that dynamic routing improves network performance only over a small parameter range, and should dynamic routing be used at all, it must be implemented with great care.
37 citations
23 Jun 1980
TL;DR: A demonstration of the versatility of the router (it is used to solve the Hampton Court Maze) and with applications of the Router in TI's I2L (Integrated Injector Logic) / STL (Schottky Transistor Logic) Automatic Layout System.
Abstract: A "generalized" channel router operates on horizontal and vertical channels generated from an irregular cell structure, and is free of a routing grid. Such a router can solve virtually any routing problem. It has two major phases: the global routing phase and the channel routing phase. This paper describes both phases as they have been implemented at TI. It concludes with a demonstration of the versatility of the router (it is used to solve the Hampton Court Maze) and with applications of the router in TI's I2L (Integrated Injector Logic) / STL (Schottky Transistor Logic) Automatic Layout System.
28 citations
TL;DR: This paper presents three recursive algorithms for computing end-to-end blocking probabilities in a network with alternate routing, based on link blocking probabilities, which are progressively more efficient.
Abstract: This paper presents three recursive algorithms for computing end-to-end blocking probabilities in a network with alternate routing, based on link blocking probabilities. The only assumption made is the statistical independence of link blocking probabilities. The first algorithm applies to arbitrary routing plans. The second algorithm applies to single-loss-route routing plans which include predictive routing plans used in advanced private networks. The second algorithm is also applicable to solving the terminal-pair reliability problem. The third algorithm applies to tandem-node-matrix-generated routing plans which include hierarchical routing plans similar to those used in North American public toll network, AT&T's CCSA, EPSCS, and ETN networks. These three algorithms are progressively more efficient.
23 citations
23 Jun 1980
TL;DR: Using this method, machine time was reduced to one-fourth and the routing completion ratio was more than 10% higher in experimental comparison with singly restricted routers of no iteration.
Abstract: This paper describes a new method of restricting search space for maze routing, to achieve a higher routing completion ratio and shorter machine time. The router is applied iteratively, expanding the width of L-shaped search space restriction from narrow one to wider ones successively. Using this method, machine time was reduced to one-fourth and the routing completion ratio was more than 10% higher in experimental comparison with singly restricted routers of no iteration. This paper also discusses an analysis to help to decide the iteration number and L-shaped path width.
9 citations
TL;DR: Simulation results reveal that this new policy is simpler to implement and yields better performance than that of distributed routing algorithm and buffer allocation flow control policy, which are currently being used in many packet switched networks.
Abstract: A new policy that can effectively handle message routing and flow control simultaneously in a packet switched computer network is presented. In such a policy, a traffic threshold level is assigned for each channel in the network. If all the channels along the preassigned primary route from current node to its destination do not exceed the predetermined traffic threshold, then the primary route is used. Otherwise, alternative route(s) are used to share the traffic load. When all the alternative routes from a source to a destination become unavailable, then the input traffic from that source to that destination is temporarily rejected. Simulation results of the behavior and performance of such a routing and flow control policy are presented. The implementation of the policy is also discussed. Simulation results reveal that this new policy is simpler to implement and yields better performance than that of distributed routing algorithm and buffer allocation flow control policy, which are currently being used in many packet switched networks.
Patent•
11 Mar 1980
TL;DR: In this article, the authors propose to extend and reconstruct a network among decentralized computers easily and automatically by sending out an MC address and an ST address of a counter for the number of passing paths by station (ST) where microcomputer (MC) is connected.
Abstract: PURPOSE:To extend and reconstruct a network among decentralized computers easily and automatically by sending out an MC address and an ST address of a counter for the number of passing paths by station (ST) where microcomputer (MC) is connected CONSTITUTION:A circuit control header, having an ST circuit control command C, is used for transmission control among STs A network header consists of destination MC address DA, transmitting address SA, and network command NC and ST performs a switching function referring to DA Information consists of the (n)-number fields A signal is transferred to destination MC via each ST, but a network information format is transferred between STs to generate this routing table Since adjacent STs are unknown in the beginning, a global address is sent to random ST and the counter for the number of paths counts ST passing through
01 Jan 1980
TL;DR: A distributed algorithm to evaluate available bandwidth between any two nodes in the network is presented to establish routes and flow-control data in a virtual circuit network in which traffic requirements are relatively steady with time.
Abstract: The concept of available bandwidth to each destination is used to establish routes and flow-control data in a virtual circuit network in which traffic requirements are relatively steady with time A distributed algorithm to evaluate available bandwidth between any two nodes in the network is presented
01 Dec 1980
TL;DR: The problem of minimum hop flow assignment and routing in computer-communication networks subject to an average message delay constraint or to a set of end-to-end average messagedelay constraints is formulated, and a simple algorithm for solution of the problem is developed.
Abstract: The problem of minimum hop flow assignment and routing in computer-communication networks subject to an average message delay constraint or to a set of end-to-end average message delay constraints is formulated, and a simple algorithm for solution of the problem is developed. The algorithm is illustrated via an example, and directions for future research are indicated.
TL;DR: This work proposes two routing methods, LRI and LRI, which are basically reinforcement methods for the learning automaton, and shows the effectiveness of these proposed methods by means of simulation on a concrete network topology.
Abstract: Learning routing is introduced to large-scale communication network to compensate the lack of a priori information on the network behavior. Learning routing consists of learning automaton as a learning controller placed at each network node. This learning automaton makes decision on routes for packets which are the basic unit of data to be transmitted through the network. Using learning automaton we propose two routing methods, LRI and LRI, which are basically reinforcement methods for the learning automaton. The effectiveness of these proposed methods is shown by means of simulation on a concrete network topology.
TL;DR: It is shown that for any fixed multiple access scheme the same routing algorithm minimizes the average delay and thus an apparent separation seems to exist and as a step toward this goal the analysis of the interacting queues that model the SIMP buffers is achieved.
TL;DR: The routing method used in Cernet, a local high-speed packet switching network on the European Organization for Nuclear Research (Cern) site, is presented, and is claimed to be simple and robust, permitting a fairly small and efficient emplementation.