Partial disjoint path for multi-layer protection in GMPLS networks

Abstract

-In this paper, different recovery methods applied at different network layers and time scales are used in order to enhance the network reliability. Each layer deploys its own fault management methods. However, current recovery methods are applied to only a specific layer. New protection schemes, based on the proposed Partial Disjoint Path algorithm, are defined in order to avoid protection duplications in a multi-layer scenario. The new protection schemes also encompass shared segment backup computation and shared risk link group identification. A complete set of experiments proves the efficiency of the proposed methods in relation with previous ones, in terms of resources used to protect the network, the failure recovery time and the request rejection ratio.Index Termns -quality of service, reliability, shared segment protection, GMPLS.

Enhanced multi-layer protection in multi-service GMPLS networks

“…1a and 1b) since the link 5-6 is already protected at the optical layer and, consequently, the SBP defined at the MPLS layer is not activated against the failure of link 5-6.This is possible if the new definition of link-disjoint path based on Shared Risk Link Group (SRLG) presented in [6] is considered. For more details refer to [6].…”

“…As presented in [6], the PDP may overlap with the links of the WP that are already protected at the optical layer and the nodes of the WP. Therefore, no extra resource is necessary in the MPLS layer against failure of protected links in the optical layer.…”

“…We propose a variation of the Partial Disjoint Path (PDP) [6] algorithm in order to identify the segment backup paths necessary to protect the working path (see section III.A). First, a weight w ij is assigned on each link according to Equation 1:…”

“…Once the WP is known, a variation of the Partial Disjoint Path (PDP) algorithm [6] is used to compute the BP. As presented in [6], the PDP may overlap with the links of the WP that are already protected at the optical layer and the nodes of the WP.…”

“…Thus, the multi-layer fault management is simplified and the resource consumption is reduced. In order to deploy this idea, the new definition of link-disjoint path using Shared Risk Link Group (SRLG) defined in [6] is taken into account. This paper also encompasses recovery methods with traffic differentiation.…”