Showing papers on "Routing protocol published in 1983"

Speech Transport in Packet-Radio Networks with Mobile Nodes

Abstract: A research effort to provide speech-carrying capabilities to a data-oriented packet-switching radio network is described. The features of the network that limit its ability to carry packetized speech are discussed, and their effects on the network performance are analyzed. A new protocol, called duct routing, that enhances the network capabilities in a mobile environment is presented. That protocol makes use of repeater redundancy to compensate for loss of communication connectivity due to node mobility. A series of experiments to evaluate the network performance in carrying speech traffic, both with data and voice protocols, is described, and the results are presented and discussed.

Dynamic Routing and Call Repacking in Circuit-Switched Networks

Abstract: The performance of three dynamic routing techniques for small circuit-switched networks is compared by simulation with three static routing techniques and with a repacking technique for calls in progress. It is found that dynamic routing algorithms improve network performance by increasing the number of paths available for call connection over what would otherwise be available to a corresponding static routing. It is also shown that call repacking increases the amount of carried traffic significantly, and that this improvement is obtained by a different mechanism than for dynamic routing. The possibility of combining the two techniques is also investigated, and general characteristics of good dynamic routing techniques are presented.

Incorporation of multiaccess links into a routing protocol

Abstract: Conventional routing protocols and algorithms work most efficiently on sparsely connected networks. Network topologies today include multiaccess links which include hundreds of nodes, all of which are capable of direct communication with each other. Some of these multiaccess links have broadcasting ability. This paper presents protocols and algorithms for efficiently dealing with the characteristics of various types of multiaccess links, when they are included as links in a general topology net.

Analysis of routing table update activity after resource failure in a distributed computer network

Abstract: In a distributed computer network each node participates in the routing process, making routing decisions based on information about network topology which is stored in tables in the node. To maintain the accuracy of these tables without interrupting the functionality of the network, they must be dynamically updated whenever there is a topology change in the network. The purpose of this paper is to analyze update activity required by a topology information maintenance scheme which has been implemented on the three-node MERIT Computer Network in Michigan. The main theorem gives upper and lower bounds on the number of update messages required after failure of a single network resource, either a node or a link.

On the structure of decentralized dynamic routing strategies

Abstract: The problem of dynamic routing in data communication networks is considered. A model is introduced which takes into proper account the decentralization of the information about the network status. The problem is thus considered in a team-theory framework and the structure of the optimal strategies is derived.

Adaptive Routing for Damaged Networks

Abstract: This paper proposes and examines adaptive routing algorithms for communication networks that are subject to damage. These algorithms route calls through the network when the network configuration is not fully known, and adaptively reorder the routing tables as they gather more information about the network configuration. (The path that a call follows in the network is determined by routing tables. When a call reaches a node, a routing table is consulted to find the next node to attempt.) We concentrate on learning mechanisms that reorder the routing tables in real-time. For example, the success-to-top mechanism moves the table entry that led to a successful connection of a call to the top of the routing table. Success-to-top leaves the relative order of the other entries in the routing table unchanged. Other possible schemes include failure-to-bottom (entries that lead to unsuccessful connection attempts are placed on the bottom of the list), and success-up-one (in which the successful entry is moved up by one in the routing table). Markov chain models are described for success-to-top and failure-to-bottom schemes. Analytical expressions for the steady-state probabilities are used to form measures for these two strategies. We compare these measures for a wide selection of blocking probabilities. Further, a simulation model is used to evaluate the merits of all three (and more) schemes. The simulation provides network measurements not available from the analytical model. The simulation also examines information sharing mechanisms in which a single call is used to change the routing tables at many nodes.

Incorporation of multiaccess links into a routing protocol

Abstract: Conventional routing protocols and algorithms work most efficiently on sparsely connected networks. Network topologies today include multiaccess links which include hundreds of nodes, all of which ...