Shared Path Protection in GMPLS networks with limited wavelength conversion capability
ABSTRACT Sharing of protection resources is a cost-effective solution to guarantee survivability against failures. In wavelength-switched optical networks (WSON), in addition to sharing the wavelengths resources, wavelength converters (WCs) can also be shared by different optical connections, or lightpaths. This paper considers the problem of ensuring 100% survivability against single-link failures in a GMPLS-enabled optical network. RSVP-TE signalling protocol extensions for wavelength sharing under Shared Path Protection have been recently proposed for networks with wavelength continuity constraint. In this work, the performance of the proposed extensions is evaluated in a network with limited wavelength conversion. Furthermore, new extensions are proposed for an efficient WC sharing and their impact on the resource sharing is evaluated by simulations. Results indicate a trade-off between providing high wavelength sharing (i.e., low wavelength overbuild) and good WC sharing.
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ABSTRACT: This article focuses on the problem of dynamic and distributed shared path protection (SPP) in all-optical GMPLS networks without wavelength conversion capability. In this scenario, both working and backup lightpaths use a single wavelength for all links in their respective paths (i.e., wavelength continuity constraint, WCC). The novelty of this work, from the best of our knowledge, is twofold: presenting and evaluating two routing approaches that besides maximizing resource usage address connection blocking caused by the WCC, and that both schemes are experimentally implemented within a real GMPLS-based network using ADRENALINE testbed. The first approach relies on partial network state information that aims at increasing backup sharing based on aggregated link bandwidth. The second approach relies on full network state information leading to both increase backup sharing based on enhanced link channel information, and reduce connection blocking due to WCC. A detailed description of the two algorithms, along with the required extensions to current GMPLS routing protocols are provided. The experimental performance evaluation and comparison of the two schemes is conducted with regard to two figures of merit: connection blocking probability and restoration overbuild. Whereas the second finer approach does imply an increase of algorithm complexity, higher control overhead and slightly lower scalability, it will be shown that it significantly reduces the blocking probability while maintaining an excellent restoration overbuild usage.Design and Reliable Communication Networks, 2007. DRCN 2007. 6th International Workshop on; 11/2007
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ABSTRACT: In this paper we propose novel wavelength assignment algorithms along with the required extensions to the current GMPLS RSVP-TE Label Set to efficiently encompass the Wavelength Continuity Constraint (WCC) and the Backup Sharing in GMPLS-enabled Wavelength-Routed Networks (WRN) with Shared Path Protection (SPP) recovery schemes. The focus of this paper is to experimentally validate in ADRENALINE testbed the proposed signalling-based solution for WCC in SPP recovery when GMPLS OSPF-TE routing protocol disseminates only aggregated link information at bandwidth level based on two approaches: Unreserved Bandwidth (UBw), as proposed in standard GMPLS, and Shamble Bandwidth (SRBw) through an extended GMPLS OSPF-TE protocol proposed by the authors. Experimental performance evaluation shows that without using full routing information (i.e., per-wavelength channel dissemination), the Resource Overbuild can be reduced up to 25% and the Blocking Probability up to 35%. Moreover, in function of the required performance, it is preferable to enhance the signalling with sharing information before adding it into the routing.Communications, 2008. ICC '08. IEEE International Conference on; 06/2008
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ABSTRACT: The GMPLS assumption that all available labels are equal is reasonable in electronic networks but not always true in WDM optical networks where labels correspond to physical wavelengths. In this paper we present two schemes for collecting the preference for specific labels during GMPLS signaling. For this purpose a new use of the Suggested Label object is proposed, and a novel object called Suggested Vector is introduced. The approach is validated through simulations showing significant wavelength converter usage reduction in a WDM optical networkIEEE Communications Letters 01/2007; · 1.16 Impact Factor