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ABSTRACT: This paper evaluates a centralised impairment-aware path restoration approach for GMPLS-controlled transparent optical networks. Experimental results on a 14-node network test-bed show successful QoT compliant path restoration of around 3.6 seconds.
Optical Communication (ECOC), 2010 36th European Conference and Exhibition on; 10/2010
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ABSTRACT: This paper presents and compares different TE information dissemination strategies between Path Computation Elements (PCEs) in multi-domain optical networks. In such network context, recent studies have found that path computation only with local domain visibility yields poor network performance. Accordingly, certain visibility between domains seems necessary. Aiming to fit the confidentiality requirements of the composing domains while improving the final network blocking probability, novel link aggregation techniques have been proposed, which summarize the state of network domains resources efficiently. This aggregated link information is afterwards disseminated to all the remainder domains in the network. To this end, we introduce different update triggering policies to make a good trade-off between routing information scalability and inaccuracy. The performance of all contributions has been supported by illustrative simulation results.
Transparent Optical Networks (ICTON), 2010 12th International Conference on; 08/2010
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ABSTRACT: A connection spanning, for example, several countries crosses multiple optical backbone networks, each one controlled by different administrators or operators. In this context, the interworking of these networks is thus necessary to set up end-to-end optical connections. A key issue when delivering such optical services is the use of efficient and fast restoration strategies to recover a connection disruption. To this end, there are several issues and policies that a network operator should address, such as interdomain failure information exchange and the point of repair (PoR) placement problem. Upon a failure's occurrence, exchanging interdomain failure information results is essential to attain both an efficient use of the network resources (i.e., wavelength channels) and a fast restoration time. In this regard, within the GMPLS (Generalized Multi-Protocol Label Switching) framework, interdomain information exchange remains unstandardized. Three network operator policies are proposed to yield different restoration mechanisms according to different interdomain failure exchanges. Additionally, three PoR strategies are pointed out and are qualitatively compared. Finally, selected policies and restoration strategies are experimentally validated and compared in terms of the restoration time. Experiments have been carried out over a multidomain optical network infrastructure connecting the GMPLS-based control planes of the UPC CARISMA and the CTTC ADRENALINE test beds.
Journal of Optical Communications and Networking 08/2010; · 1.87 Impact Factor
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ABSTRACT: This paper demonstrates the benefits of GMPLS-based integrated routing and grooming in a 16-Node ASON/GMPLS network test-bed. Experimental results highlight significant blocking probability and E/O port usage reduction against all-optical and opaque transport network alternatives.
Optical Communication, 2009. ECOC '09. 35th European Conference on; 10/2009
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ABSTRACT: The efficient accommodation of sub-wavelength client flows on optical channels is a current challenge for resources use optimization in GMPLS controlled optical networks. While optical channels capacity usually exceeds 10 Gbit/s, client connections requests show finer granularity. This paper concentrates on the design and implementation of a GMPLS-controlled grooming capable transport infrastructure on the ASON/GMPLS CARISMA test-bed. Through the paper, the operation of a GMPLS-controlled multi-layer network architecture is introduced, subsequently highlighting implementation issues that come into light. The contributions proposed in the paper are supported by illustrative experimental results.
Transparent Optical Networks, 2009. ICTON '09. 11th International Conference on; 08/2009
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ABSTRACT: Large optical backbone networks may be composed of several domains, each one controlled by different administrators/operators. Besides, the bandwidth granularity of these domains may be different. Label Switched Paths (LSPs) provisioning in multi-domain/multi-operators/multi-layer network scenarios is a challenging problem actually, which has to be properly faced. In this paper, some open issues related to end-to-end bandwidth provisioning are discussed. Among others, the grooming problem in multi-layer/multi-domain optical networks and the performance degradation of recovery mechanisms due to limited inter-domain knowledge are analyzed.
Transparent Optical Networks, 2009. ICTON '09. 11th International Conference on; 08/2009
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ABSTRACT: Aiming at better resource utilization, an important requirement of future optical transport networks is the capability to accommodate subwavelength client flows efficiently. This can be put into action thanks to the enhanced traffic engineering (TE) protocols provided within the generalized multiprotocol label switching (GMPLS) standardization. The present paper concentrates on the design and implementation of a GMPLS-controlled grooming-capable transport infrastructure, namely, the automatically switched optical network (ASON)/GMPLS CARISMA test bed. Through the paper, the operation of a GMPLS-controlled multilayer network architecture is introduced, subsequently highlighting implementation issues that come to light. Special attention is devoted to a centralized flow reallocation module deployed in the CARISMA test bed to minimize the overall network cost. In this context, an integer linear programming (ILP) formulation to obtain its optimal cost is derived and low-weighted metaheuristics providing a nearly optimal solution are additionally proposed. All contributions in the paper are supported by illustrative experimental results.
Journal of Optical Communications and Networking 08/2009; · 1.87 Impact Factor
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ABSTRACT: In this paper we propose a mechanism for connecting two or more MPLS islands belonging to the same MPLS domain through one ASON/GMPLS domain. It is based on the overlay model, where client and server networks do not exchange routing information. The interconnection is firstly done at the control plane level allowing the OSPF-TE flooding mechanism to advertise the existence of a link between two MPLS islands. Then, all MPLS routers in both parts of the MPLS domain know the complete network topology. Moreover, flooding messages advertising topological changes in one MPLS island of the domain are sent to other MPLS islands through these connections. No optical resources are used in the transport plane of the ASON/GMPLS network. New LSPs can be routed end-to-end triggering, if necessary, the establishment of LSPs in the ASON/GMPLS domain.
Optical Network Design and Modeling, 2008. ONDM 2008. International Conference on; 04/2008
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ABSTRACT: This paper deals with the implementation of the ASON/GMPLS CARISMA network, located in the premises of the Optical Communications Group of UPC. It is composed by ROADM remotely controlled by a GMPLS- based control plane. The paper highlights some open issues in the deployment of services-aware intelligent optical networks.
Transparent Optical Networks, 2007. ICTON '07. 9th International Conference on; 08/2007
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ABSTRACT: Some ideas about different traffic aggregation strategies to optimize the use of optical channels in wavelength routed networks are presented. The considered scenario assumes an integrated GMPLS control plane, responsible for the management of requested electrical IP connections, as well as the underlying lightpaths. Different grooming policies which have been studied are presented, highlighting potential benefits that each one would offer.
Transparent Optical Networks, 2007. ICTON '07. 9th International Conference on; 08/2007
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ABSTRACT: In this paper, the authors present extensions to generalized multiprotocol label switching (GMPLS) link management protocol (LMP), which allow, upon link failures, automatic LMP adjacency recovery in out-of-fiber control plane architectures. An analytical study is derived to quantify the impact of control plane failures on overall network grade of service (GoS). As a result, the most appropriate LMP Hellolnterval value can be selected, which meets the required failure recovery times and introduces the minimum control overhead. The feasibility of the proposals is validated by simulations and experimental results over the ASON/GMPLS CARISMA test-bed.
GMPLS Performance: Control Plane Resilience, 2007 Workshop on; 07/2007
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S. Spadaro,
J. Perelló, F. Agraz,
S. Azodolmolky,
M. Angelou,
Y. Qin,
R. Nejabati,
D. Simeonidou,
P. Kokkinos,
E. Varvarigos,
Y. Ye,
I. Tomkos
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S. Azodolmolky,
J. Perelló,
M. Angelou, F. Agraz,
L. Velasco,
S. Spadaro,
Y. Pointurier,
A. Francescon,
C.V. Saradhi,
P. Kokkinos,
E. Varvarigos,
S.A. Zahr,
M. Gagnaire,
M. Gunkel,
D. Klonidis,
I. Tomkos
Journal of Lightwave Technology. 29(4):439-448.
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F. Agraz,
S. Azodolmolky,
M. Angelou,
J. Perello,
L. Velasco,
S. Spadaro,
A. Francescon,
C.V. Saradhi,
Y. Pointurier,
P. Kokkinos,
E. Varvarigos,
M. Gunkel,
I. Tomkos
Optical Fiber Communication (OFC), collocated National Fiber Optic Engineers Conference, 2010 Conference on (OFC/NFOEC);
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J. Perello,
S. Spadaro, F. Agraz,
M. Angelou,
S. Azodolmolky,
Y. Qin,
R. Nejabati,
D. Simeonidou,
P. Kokkinos,
E. Varvarigos,
S. Al Zahr,
M. Gagnaire,
I. Tomkos
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S. Azodolmolky,
J. Perelló,
M. Angelou, F. Agraz,
L. Velasco,
S. Spadaro,
Y. Pointurier,
A. Francescon,
C.V. Saradhi,
P. Kokkinos,
E. Varvarigos,
S. Al Zahr,
M. Gagnaire,
M. Gunkel,
D. Klonidis,
I. Tomkos
Lightwave Technology, Journal of. 29(4):439-448.
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S. Spadaro,
J. Perello, F. Agraz,
S. Azodolmolky,
M. Angelou,
Y. Qin,
R. Nejabati,
D. Simeonidou,
P. Kokkinos,
E. Varvarigos,
Y. Ye,
I. Tomkos
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Transparent Optical Networks (ICTON), 2011 13th International Conference on;