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Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we tackle the problem of how to expand Internet protocol (IP) networks with performance guarantees, in a cost-effective way. We first propose an optimization model that deals with selecting the location of the routers, selecting their types, expanding the access and the backbone networks and selecting the transmission link types. The model also considers the routing of the IP traffic using a standardized routing protocol. The performance guarantees we refer to are bandwidth guarantees between the clients' routers. The performance guarantees stand not only for the normal state of the network, but also for all failure scenarios of interest to the network planner. A tabu-based metaheuristic algorithm is proposed to find solutions of the model. Numerical results show that "good" solutions can be found using the proposed algorithm. [ABSTRACT FROM AUTHOR]

Users of wide area computer networks vary both in terms of their service requirements and of their communication characteristics. Examples of such distinguishing factors are type of service, priority level, message length, etc. This paper presents a system that provides the network designer with a means to define good fixed routes to be used by the different classes of messages in the network. The main tradeoffs inherent to the problem are captured in an analytical model for which efficient solution methods are developed. The resulting algorithm is tested on several example networks, and the main results of extensive computational experiments are reported. [ABSTRACT FROM AUTHOR]

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The optimum Steiner Tree problem in a (nondirected) graph is known to belong to the class of NP-hard problems. However large scale instances (typically hundreds or thousands of nodes) arise in such important applications as optimal communication network design, or VLSI routing. There is therefore a strong need for efficient heuristics. We discuss in this paper efficient implementations of greedy-type procedures for approximate solution of symmetric Steiner Tree problems with arbitrary nonnegative lengths on the edges. A special subclass of problems (meeting the so-called "nonadjacency condition") is also introduced and studied. Various ways of improving the computational efficiency of the basic greedy algorithm are examined, among which the use of reoptimization procedures and proper exploitation of a supermodularity property of an associated set function; thanks to the latter the total number of minimum spanning tree computations can be significantly reduced according to the "accelerated greedy algorithm" principle (Minoux 1977), and lower bounds can be derived (thus providing estimates of the quality of the approximate solutions obtained). [ABSTRACT FROM AUTHOR]

Easily manipulated list structures for recording the basis tree for adjacent extreme point (“simplex type”) network algorithms are paramount to the development of computationally efficient network algorithms. This paper presents a new list structure which is shown to be computationally more efficient and to require one-third less computer memory to implement than all alternate list structures. [ABSTRACT FROM AUTHOR]