Network protection with multiple availability guarantees

We develop a novel network protection scheme that provides guarantees on both the fraction of time a flow has full connectivity, as well as a quantifiable minimum grade of service during downtimes. In particular, a flow can be below the full demand for at most a maximum fraction of time; then, it must still support at least a fraction q of the full demand. This is in contrast to current protection schemes that offer either availability-guarantees with no bandwidth guarantees during the downtime, or full protection schemes that offer 100% availability after a single link failure. We develop algorithms that provide multiple availability guarantees and show that significant capacity savings can be achieved as compared to full protection. If a connection is allowed to drop to 50% of its bandwidth for 1 out of every 20 failures, then a 24% reduction in spare capacity can be achieved over traditional full protection schemes. In addition, for the case of q = 0, corresponding to the standard availability constraint, an optimal pseudo-polynomial time algorithm is presented.National Science Foundation (U.S.) (NSF grants CNS-1116209)National Science Foundation (U.S.) (NSF grants CNS-0830961)United States. Defense Threat Reduction Agency (grant HDTRA-09-1-005)United States. Defense Threat Reduction Agency (grant HDTRA1-07-1-0004)United States. Air Force (Air Force contract # FA8721-05-C-0002

Designing multi-layer provider networks for circular disc failures

We examine the issue of disaster recovery after zonal outages in core networks, especially IP-over-WDM multi-layer networks. In particular, we consider the network design problem for a regional failure of circular area of radius R. Our goal is to design a network that can withstand a randomly located single failure of radius R. To this end, we formulate the problem as a constrained optimization problem whose solution for both IP-over-optical networks and pure ROADM-based networks is proposed. Subsequently, we develop an efficient heuristic based on a divide and conquer strategy that gives acceptable results. We also discuss the role of SDN in design and restoration of such networks. Simulation results are showcased over a core network topology thereby realizing the plausibility of such network design

Availability-Aware Spare Capacity Allocation with Partially Protected Rings

This thesis work focuses on designing a survivable IP-core network with the minimal investment of spare capacity. A span-oriented spare capacity allocation (SCA) scheme is proposed to satisfy customers' availability requirements in the end-to-end (E2E) sense. The novelty of the proposed SCA scheme is that it meets the E2E availability requirements despite the lack of knowledge of E2E bandwidth by employing protection rings covering all links in the network. Different ring selection methods are presented and also compared from the aspect of network redundancy and LP feasibility which provide more flexibility to the design. The proposed SCA algorithm further minimizes total cost of spare capacity by incorporating partial protection within the proposed architecture. The simulation results show that it can significantly reduce the spare capacity consumption depending on the availability. The proposed SCA scheme also performs better in terms of redundancy than that of two other dominant methods available these days

Differentiated QoS for survivable WDM optical networks

10.1109/MCOM.2004.1299335IEEE Communications Magazine425S8-S14ICOM

Network protection with service guarantees

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2013.This electronic version was submitted and approved by the author's academic department as part of an electronic thesis pilot project. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from department-submitted PDF version of thesis.Includes bibliographical references (p. 167-174).With the increasing importance of communication networks comes an increasing need to protect against network failures. Traditional network protection has been an "all-or-nothing" approach: after any failure, all network traffic is restored. Due to the cost of providing this full protection, many network operators opt to not provide protection whatsoever. This is especially true in wireless networks, where reserving scarce resources for protection is often too costly. Furthermore, network protection often does not come with guarantees on recovery time, which becomes increasingly important with the widespread use of real-time applications that cannot tolerate long disruptions. This thesis investigates providing protection for mesh networks under a variety of service guarantees, offering significant resource savings over traditional protection schemes. First, we develop a network protection scheme that guarantees a quantifiable minimum grade of service upon a failure within the network. Our scheme guarantees that a fraction q of each demand remains after any single-link failure, at a fraction of the resources required for full protection. We develop both a linear program and algorithms to find the minimum-cost capacity allocation to meet both demand and protection requirements. Subsequently, we develop a novel network protection scheme that provides guarantees on both the fraction of time a flow has full connectivity, as well as a quantifiable minimum grade of service during downtimes. In particular, a flow can be below the full demand for at most a maximum fraction of time; then, it must still support at least a fraction q of the full demand. This is in contrast to current protection schemes that offer either availability-guarantees with no bandwidth guarantees during the down-time, or full protection schemes that offer 100% availability after a single link failure. We show that the multiple availability guaranteed problem is NP-Hard, and develop solutions using both a mixed integer linear program and heuristic algorithms. Next, we consider the problem of providing resource-efficient network protection that guarantees the maximum amount of time that flow can be interrupted after a failure. This is in contrast to schemes that offer no recovery time guarantees, such as IP rerouting, or the prevalent local recovery scheme of Fast ReRoute, which often over-provisions resources to meet recovery time constraints. To meet these recovery time guarantees, we provide a novel and flexible solution by partitioning the network into failure-independent "recovery domains", where within each domain, the maximum amount of time to recover from a failure is guaranteed. Finally, we study the problem of providing protection against failures in wireless networks subject to interference constraints. Typically, protection in wired networks is provided through the provisioning of backup paths. This approach has not been previously considered in the wireless setting due to the prohibitive cost of backup capacity. However, we show that in the presence of interference, protection can often be provided with no loss in throughput. This is due to the fact that after a failure, links that previously interfered with the failed link can be activated, thus leading to a "recapturing" of some of the lost capacity. We provide both an ILP formulation for the optimal solution, as well as algorithms that perform close to optimal.by Gregory Kuperman.Ph.D

Differentiated quality-of-recovery and quality-of-protection in survivable WDM mesh networks

In the modern telecommunication business, there is a need to provide different Quality-of-Recovery (QoR) and Quality-of-Protection (QoP) classes in order to accommodate as many customers as possible, and to optimize the protection capacity cost. Prevalent protection methods to provide specific QoS related to protection are based on pre-defined shape protection structures (topologies), e.g., p -cycles and p -trees. Although some of these protection patterns are known to provide a good trade-off among the different protection parameters, their shapes can limit their deployment in some specific network conditions, e.g., a constrained link spare capacity budget and traffic distribution. In this thesis, we propose to re-think the design process of protection schemes in survivable WDM networks by adopting a hew design approach where the shapes of the protection structures are decided based on the targeted QoR and QoP guarantees, and not the reverse. We focus on the degree of pre-configuration of the protection topologies, and use fully and partially pre-cross connected p -structures, and dynamically cross connected p -structures. In QoR differentiation, we develop different approaches for pre-configuring the protection capacity in order to strike different balances between the protection cost and the availability requirements in the network; while in the QoP differentiation, we focus on the shaping of the protection structures to provide different grades of protection including single and dual-link failure protection. The new research directions proposed and developed in this thesis are intended to help network operators to effectively support different Quality-of-Recovery and Quality-of-Protection classes. All new ideas have been translated into mathematical models for which we propose practical and efficient design methods in order to optimize the inherent cost to the different designs of protection schemes. Furthermore, we establish a quantitative relation between the degree of pre-configuration of the protection structures and their costs in terms of protection capacity. Our most significant contributions are the design and development of Pre-Configured Protection Structure (p-structure) and Pre-Configured Protection Extended-Tree (p -etree) based schemes. Thanks to the column generation modeling and solution approaches, we propose a new design approach of protection schemes where we deploy just enough protection to provide different quality of recovery and protection classe

Pour un mécanisme de protection différenciée unique contre la gestion ainsi que les pannes : DiffServ*

L'avènement de l'Internet multiservice met fin à l'ère du réseautage de nature meilleur effort. Cette nouvelle caractéristique est très souhaitable et prometteuse sur plusieurs plans mais elle reste sujette à la capacité du réseau de protéger chaque catégorie de trafic selon sa priorité et ses exigences en qualité de service. Quand le réseau est déployé sur une infrastructure optique, une des préoccupations des plus importantes est sa capacité de survie et le maintien d'un service adéquat à toutes les applications suite à une panne physique. Nous savons qu'une simple coupure de fibre provoque des pertes énormes en capacité de transmission et si laissée sans surveillance, elle peut causer des dégradations majeures dans la qualité de service perçue par les usagers du réseau. Bien qu'il existe déjà des mécanismes de protection physique qui sont conçus spécifiquement pour remédier à de telles situations, ces options sont généralement très coûteuses et difficilement adaptable aux besoins variés de chaque classe de trafic d'un réseau multiserviceNous proposons alors un modèle innovateur de protection différenciée du trafic, DiffServ*, qui permet de répondre aux exigences particulières en qualité de service et de protection de chacune des classes de trafic et qui introduit une robustesse accrue et des économies importantes en matière d'utilisation de ressources d'un réseau IP/WDM. DiffServ* se distingue par l'utilisation combinée de l'architecture des services différenciées à la couche logique d'un réseau et de la technique d'agrégation de liens ou canaux disjoints à sa couche physiqueNotre modèle de protection différenciée du trafic en cas de pannes a été soumis à l'épreuve, nous avons utilisé la simulation pour étudier sa performance et nous l'avons comparé à un modèle de protection physique homologue, DiffProtect. Les résultats montrent que DiffServ* permet en moyenne de garantir une meilleure protection que DiffProtect en cas de pannes simples et multiples. DiffProtect n'est plus performant que dans certaines situations de pannes et de trafic très particulières. Une évaluation subséquente de la fiabilité d'un réseau qui utilise DiffServ*, une étude de coût de son déploiement et une étude de cas qui cible les réseaux MPLS-DiffServ TE confirment davantage la supériorité de DiffServ* par rapport à tout autre option de protection différenciée envisageableNous rappelons que DiffServ* se base sur les techniques de différenciation de service de la couche logique pour protéger le trafic en cas de pannes de composantes optiques. Ceci est inédit puisque ces mêmes techniques sont originalement conçues que pour protéger le trafic en cas de congestion dans la couche logique. Alors pour démontrer définitivement que DiffServ* est réalisable et fonctionnel nous réalisons une expérience de déploiement pratique de DiffServ* en laboratoire à l'aide d'équipements de communication réel. Malgré les divergences techniques entre la modélisation théorique de DiffServ* et de son implémentation, DiffServ* est démontré performant, fiable, économique et réalisable en pratiqueNous clôturons ce projet par une planification de déploiement ; cette dernière permet de généraliser le déploiement de DiffServ* à toute topologie IP/WDM et d'en dimensionner la couche logique. Notre procédure approche les situations qui requièrent la fiabilité spécifique de DiffProtect en offrant un modèle d'optimisation complet sur le déploiement de la protection MixProtect multicouche qui utilise DiffServ* et DiffProtect dans le même résea

Differentiated Optical Qos Under A Low Complexity Fwm-aware Wavelength Assignment Algorithm

Optical Quality of Service (QoS) for different classes of service in dynamic transparent optical networks is here addressed through Four Wave Mixing (FWM)-aware algorithms. The traffic classes differ in quality attributes, namely, transmission Bit Error Rate (BER) and blocking probability. The algorithms are tested on two mesh topologies against offered traffic, for different numbers of wavelengths per link. Results suggest that in order to simultaneously maintain Optical Service Level Agreement (OSLA) and efficient utilization of the resources, there must be some form of Connection Admission Control (CAC) mechanisms able to provide class isolation. This paper shows that this can be done either explicity or through a simple mechanism that is able to reduce lightpath non-linear interaction and favour the admission of high-priority traffic. A scalable and efficient mechanism based on shortest route, congestion avoidance and first fit wavelength assignment is suggested as a practical solution to QoS-Aware multiservice optical network. © 2005 IEEE.2005431438Kaheel, A., Khattab, T., Mohamed, A., Alnuweiri, H., Quality-of-service mechanisms in IP-over-WDM networks (2002) Communications Magazine, 40, pp. 38-43. , DecBraden, R., Integrated services in the internet architecture: An overview (1994) RFC, 1633. , JunBlake, S., An architecture for differentiated services (1998) RFC, 2475. , DecAhmed, C.B., Boudriga, N., Obaidat, M.S., Supporting adaptive QoS for multiple classes of service in DWDM networks (2001) Proc. IEEE Int. Conf. on Parallel Processing Workshops, pp. 283-288. , SeptRamaswami, R., Sivaraja, K.N., (2002) Optical Networks: A Practical Perspective, 2nd Ed., , San Francisco, CA: Morgan Kaufmann PublishersQiao, C., Yoo, M., Optical Burst Switching (OBS) - A new paradigm for an optical internet (1999) Journal of High Speed Networks, 8, pp. 69-84. , JanXu, L., Perros, H.G., Rouskas, G., Techniques for optical packet switching and optical burst switching (2001) Communications Magazine, 39, pp. 136-142. , JanGiroux, N., Ganti, S., (1999) Quality of Service in ATM Networks: State-of-the-art Traffic Management, , New Jersey, Prentice-HallFredette, A., Lang, J.P., Link Management Protocol (LMP) for Dense Wavelength Division Multiplexing (DWDM) optical line systems (2003) Internet Draft (Work in Progress), Draft-ietf-ccamp-lmp-wdm-03.txt, , Dec(2000) Characteristics of Transport Equipment - Description Methodology and Generic Functionality, , ITU-T Rec. G.806, OctFonseca, I.E., Ribeiro, M.R.N., Almeida Jr., R.C., Waldman, H., Preserving global optical QoS in FWM impaired dynamic networks (2004) Electronics Letters, 40, pp. 191-192. , FebLevandovsky, D., Wavelength routing based on physical impairments (2001) Proc. IEEE OFC'01, pp. TuG71-TuG73Ramamurthy, B., Datta, D., Feng, H., Heritage, J.P., Mukherjee, B., Impact of transmission impairments on the teletraffic performance of wavelength-routed optical networks (1999) J. Ligthwave Technology, 17, pp. 1713-1723. , OctAli, M., Tancevski, L., Impact of polarization-mode dispersion on the design of wavelength-routed networks (2002) Photonics Technology Letters, 14, pp. 720-722. , MaySaradhi, C.V., Gurusamy, M., Zhou, L., Differentiated QoS for survivable WDM optical networks (2004) Communications Magazine, 42, pp. S8-S14. , MayJukan, A., Van As, H.R., Service-specific wavelength allocation in QoS-routed optical networks (1998) IEEE GLOBECOM'98, 4, pp. 2270-2275. , Nov(2002) Spectral Grids for WDM Application: DWDM Frequency Grid, , ITU-T Rec. G.694.1, JunSong, S., Allen, C., Demarest, K., Pelz, L., Fang, X., Pua, Y., Experimental study of four wave mixing in non-zero dispersion fiber (1997) Proc. IEEE LEOS '97, 2, pp. 224-225. , NovXu, B., Brandt-Pearce, M., Comparison of FWM- and XPM-induced crosstalk using the Volterra series transfer function method (2003) J. Ligthwave Technology, 21, pp. 40-53. , JanSong, S., Allen, C.T., Demarest, K.R., Hui, R., Intensity-dependent phase-matching effects on four-wave mixing in optical fibers (1999) J. Lightwave Tecnology, 17, pp. 2285-2290. , NovInoue, K., A simple expression for optical FDM network scale considering fiber FWM and optical amplifier noise (1995) J. Ligthwave Technology, 13, pp. 856-861. , MayZang, H., Jue, J.P., Mukherjee, B., A review of routing and wavelength assignment approaches for wavelength-routed optical WDM networks (2000) SPIE Optical Network Magazine, 1, pp. 47-60. , DecFonseca, I.E., Ribeiro, M.R.N., Almeida Jr., R.C., Waldman, H., Meeting optical QoS in dynamic networks with reduced complexity (2004) Proc. ECOC'04, 3, pp. 750-751. , paper We4P141, SeptAgrawal, G.P., (2001) Nonlinear Fiber Optics, 3rd Ed, , San Diego, CA: Academic Pres