Constrained and Unconstrained overspill routing in optical networks: a detailed performance evaluation

Abstract

In this article, we present a detailed performance evaluation of a hybrid optical switching (HOS) architecture called Overspill Routing in Optical Networks (ORION). The ORION architecture combines (optical) wavelength and (electronic) packet switching, so as to obtain the individual advantages of both switching paradigms. In particular, ORION exploits the possible idle periods of established lightpaths to transmit packets destined to the next common node, or even directly to their common end-destination. Depending on whether all lightpaths are allowed to simultaneously carry and terminate overspill traffic or overspill is restricted to a sub-set of wavelengths, the architecture limits itself to constrained or un-constrained ORION. To evaluate both cases, we developed an extensive network simulator where the basic features of the ORION architecture were modeled, including suitable edge/core node switches and load-varying sources to simulate overloading traffic conditions. Further, we have assessed various aspects of the ORION architecture including two basic routing/forwarding policies and various buffering schemes. The complete network study shows that ORION can absorb temporal traffic overloads, as intended, provided sufficient buffering is present. We also demonstrate that the restriction of simultaneous packet insertions/extractions, to reduce the necessary interfaces, do not deteriorate performance and thus the use of traffic concentrators assure ORION's economic viability.

Performance Evaluation and Design of Polymorphous OBS Networks With Guaranteed TDM Services

“…The need for this high-class virtual circuit-switched transport service, together with the current limitations of OPS and OBS technologies, has boosted research on hybrid optical approaches, see for instance [20]- [23]. Such architectures propose to combine wavelength-switched transport and highly dynamic OBS traffic over shared WDM resources.…”

Architecture and Performance Evaluation of a Novel Optical Packet Switch with Input Concentrators

“…Ref. [16] proposed the constrained ORION and pointed out the considerable advantages compared with the unconstrained ORION. However, the detailed architecture of how to implement the concentration is not described.…”