Showing papers on "Link-state routing protocol published in 1977"

A Minimum Delay Routing Algorithm Using Distributed Computation

Abstract: An algorithm is defined for establishing routing tables in the individual nodes of a data network. The routing table at a node i specifies, for each other node j , what fraction of the traffic destined for node j should leave node i on each of the links emanating from node i . The algorithm is applied independently at each node and successively updates the routing table at that node based on information communicated between adjacent nodes about the marginal delay to each destination. For stationary input traffic statistics, the average delay per message through the network converges, with successive updates of the routing tables, to the minimum average delay over all routing assignments. The algorithm has the additional property that the traffic to each destination is guaranteed to be loop free at each iteration of the algorithm. In addition, a new global convergence theorem for noncontinuous iteration algorithms is developed.

Implementing vehicle routing algorithms

Abstract: Heuristic programming algorithms frequently address large problems and require manipulation and operation on massive data sets. The algorithms can be improved by using efficient data structures. With this in mind, we consider heuristic algorithms for vehicle routing, comparing techniques of Clarke and Wright, Gillett and Miller, and Tyagi, and presenting modifications and extensions which permit problems involving hundreds of demand points to be solved in a matter of seconds. In addition, a multi-depot routing algorithm is developed. The results are illustrated with a routing study for an urban newspaper with an evening circulation exceeding 100,000.

The Modeling of Adaptive Routing in Data-Communication Networks

Abstract: Basic analytical models for problems of dynamic and quasi-static routing in data-communication networks are introduced. The models are intended to handle the quantities of interest in an algorithmic form, and as such require only a minimal number of assumptions. Control and estimation methods are used to construct algorithms for the solution of the routing problem.

Source routing in computer networks

Abstract: As plans for network interconnection develop, the problems of internet routing and addressing become increasingly important. In one popular model of internet addressing, a hierarchical form of network and local (within network) address is used, with the source providing only the destination address while the intermediate network(s) and/or Gateways between networks take care of routing packets to that destination by various paths. This and related techniques requiring some form of routing table and knowledge at intermediate nodes are more fully discussed in [1,2,3].This paper considers another technique for internet routing in which the source of internet packets specifies the complete internet route. When the entire route accompanies each internet packet, no routing decisions or tables are required at Gateways, but the packet format is complicated and overhead increases. In particular, the packet must carry a varying number of intermediate addresses depending on the path and destination [4]. This overhead may be reduced by setting up a fixed route with connection tables [1] when a connection is established.

Application of Learning Automata to Telephone Traffic Routing and Control

Abstract: Application of learning automata theory to telephone traffic routing and control is described. Improved network performance is demonstrated through the comparative simulation of learning automata routing and the existing fixed rule alternate routing in simple telephone networks. Learning automata routing results in significantly lower blocking probability when selected overload conditions prevail and additional capacity exists elsewhere in the network.

A Class of Decentralized Routing Algorithms Using Relaxation

Abstract: An important problem in packet-switched communication networks is the optimal assignment of routes to the message packets. An optimal routing assignment is one which chooses network paths for the packets in a way that minimizes some cost function, typically average message delay. A class of optimal routing algorithms is described which utilize a type of iterative computation known as relaxation. Computation is decentralized in the sense that each node computes its routing strategy using only information supplied from adjacent nodes. Being iterative, the algorithms are inherently adaptive. The routing computation is based conceptually on an electrical network analog for the optimization problem. We show that a simple, convergent relaxation procedure can be used to "solve" the analog network, thereby yielding the optimal routing strategy. A simple example is presented to illustrate the method. In general, the computational load compares favorably with other (centralized) methods, although further work is needed to obtain quantitive comparisons in specific cases.

Analysis of a Packet-Switched Network with End-to-End Congestion Control and Random Routing

Abstract: This concise paper extends the results of Pennotti and Schwartz by proposing a queueing model of a communication network with random routing and end-to-end congestion control. Using conventional performance criteria, the performance of this model is compared with that of a previously published model, where fixed routing was employed.

Evaluating a Sequential Vehicle Routing Algorithm

Abstract: The Clarke-Wright algorithm is a heuristic algorithm which has been implemented frequently and successfully to solve large-scale vehicle routing problems. In this paper, we focus on evaluating the accuracy of the Clarke-Wright procedure in its sequential form. We present examples of pathological behavior and suggest algorithm modifications to help overcome these problems.

Saturation routing network limits

Abstract: Saturation routing means a flooding of a network with messages which search for a particular subscriber's number without regard to where that subscriber is located in the network. Saturation routing, often thought of as inappropriate in a communication network, can be a useful routing scheme with the use of state-of-the-art design. In this paper, consideration will be spent on the kinds of networks in which saturation routing is applicable, and how it compares with other routing systems. The functional designs of saturation routing will be combined with the appropriate variables to create a mathematical model for performing of saturation routing in a network. The following are some of the variables: i) processor rate; ii) transmission data rate; iii) hierarchy; iv) queuing delays; v) traffic; vi) message size. The paper will be concluded with an example of a realistic network using saturation routing.

Local congestion control in computer-communication networks with random routing

Abstract: This paper considers the problem of congestion in message-switched, or packet-switched, networks, which employ probabilistic routing schemes. A queueing model for the analysis of a local congestion control scheme is presented. Analytic study of the model shows that local congestion control with random routing is superior to similar control with deterministic routing for a particular example worked out here.

Comparative Analysis of Routing Algorithms for Computer Networks

Abstract: : The routing problem in a computer-communication network is modeled as a multicommodity flow problem. Two generalizations of the EF algorithm of Cantor and Gerla for solving the nonlinear multicommodity flow problem are presented. These generalizations are of interest because they retain identity of the components of the solution in an implicit and compact manner. A mini-max routing problem is defined as a linear program, and a methodology for its solution as both a linear and nonlinear program is presented. The two approaches are compared with each other, and a lower bound on the solution is developed for the nonlinear approach. Two shortest route algorithms which are very efficient for classes of topologies likely to be considered in routing problems are introduced. The shortest route problem is a subproblem of all of the routing algorithms mentioned above. The computer load sharing problem is formulated as a multicommodity flow problem. An algorithm is presented to solve the load sharing problem which exploits the special structure of the problem.

A Routing Algorithm for Digraphs

Abstract: : A new algorithm for routing data packets in networks of computers connected by communication links is given by Chyung and Reddy. Because they assume that the communication links are two-way, their result applies, properly, to routing messages in a graph. However, some communication networks have asymmetrical cross links either by design or because the radio circuits that must be paralleled in opposite directions to compose them may fail. Such networks are represented by digraphs and it is clear that they require a generalized routing algorith. A simple modification of Chyung and Reddy's routing algorithm, shown below, provides this generalization.

Priority queueing for the autodin store-and-forward network

Abstract: An adaptive routing algorithm for store-and-forward networks is proposed. The messages in the system are transmitted in their full length, and they are assigned priorities. The algorithm's objective is to minimize delay per message and maximize message delivery rate.