Showing papers on "Link-state routing protocol published in 1980"
TL;DR: An overview is provided in this paper of the routing procedures used in a number of operating networks, as well as in two commercial network architectures, which include the IBM SNA and the DEC DNA.
Abstract: An overview is provided in this paper of the routing procedures used in a number of operating networks, as well as in two commercial network architectures. The networks include TYMNET, ARPANET, and TRANSPAC. The network architectures discussed are the IBM SNA and the DEC DNA. The routing algorithms all tend to fall in the shortest path class. In the introductory sections, routing procedures in general are discussed, with specialization to shortest path algorithms. Two shortest path algorithms, one appropriate for centralized computation, the other for distributed computation, are described. These algorithms, in somewhat modified form, provide the basis for the algorithms actually used in the networks discussed.
268 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
TL;DR: The problem of devising a good updating protocol is shown to be a problem in the management of a distributed data base and the requirements which any such protocol must meet are presented and discussed.
68 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
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.
9 citations
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.
3 citations
TL;DR: Two possible designs of access protocols for integrated computer networks with combined circuit and packet switching capabilities are discussed, i.e. pure circuit or packet protocols, with future integration in mind.
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: In this article, a queueing model for the analysis of a local congestion control scheme is presented, and an analytical study of the model shows that LCC witb random routing is superior to similar control with deterministic routing at least for the particular example considered here.
Abstract: A queueing model for the analysis of a local congestion control scheme is presented. Analytic study of the model shows that local congestion control witb random routing is superior to similar control with deterministic routing at least for the particular example considered here.
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.