Multihop Virtual Topology Design in WDM Optical Networks for Self-Similar Traffic

Abstract

Abstract. In this paper, we consider the problem of designing virtual topologies for multihop optical WDM networks when the traffic is self-similar in nature. Studies over the last few years suggest that the network traffic is bursty and can be much better modeled using self similar process instead of Poisson process. We examine buffer sizes of a network and observe that, even with reasonably low buffer overflow probability, the maximum buffer size requirement for self-similar traffic can be very large. Therefore, a self-similar traffic model has an impact on the queuing delay which is usually much higher than that obtained with the Poisson model. We investigate the problem of constructing the virtual topology with these two types of traffic and solve it with two algorithmic approaches: Greedy (Heuristic) algorithm and Evolutionary algorithm. While the greedy algorithm performs a leastcost search on the total delay along paths for routing traffic in a multihop fashion, the evolutionary algorithm uses genetic methods to optimize the average delay in a network. We analyze and compare our proposed algorithms with an existing algorithm via different performance parameters. Interestingly, with both the proposed algorithms the difference in the queuing delays, caused by self-similar and Poisson traffic, results in different multihop virtual topologies.

Genetic Algorithms for Semi-Static Wavelength-Routed Optical Networks

“…In order to evaluate the performance of the different versions of GALD, a simulation study was developed in a simulator based on OMNeT++ using the 14-node NSFNet (Ghose et al, 2005) as network topology and assuming that cables consisted of two unidirectional fibers (one for each direction). The capacity of a wavelength was set to 10 Gbps and the traffic load was normalized by the lightpath capacity.…”

Multiobjective network design for realistic traffic models

“…Although, Poisson process has been vastly used in the past to model traffic in conventional networks, recently it has been shown that Internet traffic exhibits selfsimilar bursts [12,24]. We provide a mathematical formulation for the two traffic models below.…”

“…Such a topology design should consider simultaneous optimization of network cost, average delay, and number of packets delivered subject to reliability, bandwidth and/or flow-constraints. Moreover as shown in [12,24] , the traffic model considered should be self similar in nature.…”

“…We consider average network delay and network cost as the two optimization objectives subject to satisfaction of reliability and flow constraints. For delay, we consider self-similar traffic models [12,24] and compare the topologies with those obtained through the Poisson model.…”

Implementation of Dynamic Programing to Find All Pairs Shortest Path on Fibre Optics Networks to Produced Optimized Routing and Virtual Topology

“…A number of heuristic algorithms are given in the literature [Banerjee et al, 2000;Ozdaglar et al, 2003]. [7]Ghose, Kumar, Banerjee and Dutta [Ghose et al, 2005] compared the queuing delay in an optical network using both Poisson and self-similar traffic. They showed that the virtual topologies designed using self-similar traffic are more effective in handling present day brusty Internet traffic.…”