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Please use this identifier to cite or link to this item: http://www.lib.ncsu.edu/resolver/1840.16/1313

Title: A Simulation Study of Wavelength Assignment and Reservation Policies with Signaling Delays
Authors: Iyer, Vijay R
Advisors: Dr. George N. Rouskas, Committee Chair
Dr. Douglas S. Reeves, Committee Member
Dr. Rudra Dutta, Committee Member
Keywords: Simulation
Optical Networks
CR-LDP
Wavelength Reservation
Signaling Delay
Wavelength Assignment
Issue Date: 21-Nov-2002
Degree: MS
Discipline: Computer Networking
Abstract: This thesis studies the effect of non-negligible signaling delays on the performance of wavelength-assignment heuristics, wavelength reservation schemes, routing schemes, holding time (average being 1/μ) of the lightpaths and traffic loads (average being λ/μ), in second-generation optical wide area networks (WANs). A network simulator was developed using the C++ language for this study. The simulator supports any input topology with single or multi-fiber links, many routing schemes (static, alternate and dynamic), dynamic traffic loads, and may be modified easily to accomodate different wavelength-assignment policies. The signaling messages used, in our study, to establish lightpaths, follow the Constrained-Routing Label Distribution Protocol (CR-LDP) semantics. The problem studied here falls under the general category of Routing and Wavelength Assignment (RWA) Problem which has been proved to be NP-hard. Previous studies have mostly considered static routing (with static or dynamic traffic demand), and static traffic demand (with static or alternate routing) under zero propagation delays. A few papers in the recent past have studied the effect of signaling delays but have been limited in scope. We study the effect of varying holding times, compare random versus first-fit wavelength assignment policy, compare fixed versus alternate routing, compare backward wavelength reservation schemes to forward reservation schemes, and lastly study the effect of traffic loads. We find that, in general, the random wavelength assignment policy performs better than first-fit policy and that under certain conditions, alternate routing scheme performs worse than fixed routing scheme.
URI: http://www.lib.ncsu.edu/resolver/1840.16/1313
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