Evaluating dual-failure restorability in mesh-restorable WDM optical networks

Abstract

Double link failure models, in which any two links in the network fail in an arbitrary order, are becoming critical in survivable optical network design. A significant finding is that designs offering complete dual-failure restorahility require almost triple the amount of spare capacity.In this paper, networks are designed to achieve 100% restorability under single link failures, while maximizing coverage against any second link failure in the network. In the event of a single link failure, the restoration model attempts to dynamically find a second alternate link-disjoint end-to-end path to provide coverage against a sequential overlapping link failure. Sub-graph routing [l] is extended to provide dual-failure restorahility for a network provisioned to tolerate all single-link failures. This strategy is compared with shared-mesh protection.The results indicate that subgraph routing can achieve overlapping second link failure restorability for 9599% of connections. It is also observed that subgraph routing can inherently provide complete dual-failure coverage for -7241% of the connections.

Spare Capacity Reprovisioning for Shared Backup Path Protection in Dynamic Generalized Multi-Protocol Label Switched Networks

“…The availability constraint of each connection, nonetheless, is either considered separately from the cost optimization process [4], [9]- [13], or totally ignored [3], [5]- [8], [14]. In some cases, such as all-optical bandwidth provisioning with lightpaths in Wavelength Division Multiplexing (WDM) networks, keeping the traffic uniformity and connection indivisibility in the restoration process is inevitable.…”

Multiple link failure recovery in survivable optical networks

“…In [3], the authors focused on double-link failure scenarios and presented a backup reprovision scheme to provide new backup lightpaths for connections that became unprotected due to the first failure. In [4], the authors presented a sub-graph routing strategy to tolerate double-link failure scenarios. In [5], the authors summarize backup capacity sharing rules in two-link failure scenarios and present a path-based integer-programming formulation for static traffic to optimize the total network capacity for protection against twolink failures.…”

“…Recently, there are some researches [3][4][5][6][7][8][9][10] on WDM network recovery schemes against double-link failure cases. In [3], the authors focused on double-link failure scenarios and presented a backup reprovision scheme to provide new backup lightpaths for connections that became unprotected due to the first failure.…”

“…In protection schemes, sharing of backup bandwidth provides significant saving of network capacity. Hence, many studies [1][2][3][4][5][6][7][8][9][10] focus on the algorithms and the schemes for sharing backup bandwidth among connections. In [1], the authors develop path-based and link-based ILP formulations under static traffic demand for designing protection against single-link failure.…”

Connection availability analysis of span-restorable mesh networks

“…But its discussion about path availability was only conducted under the assumption that all spans have the same physical unavailability for a path composed of four hops and no case study of path availabilities of a real network was presented. Dual failure restorability has been studied [10,11] and restoration from any second span failure was maximized in networks with 100% restorability to single-span failures. The first analytical consideration of the availability of paths in a network protected by preconfigured protection cycles was presented in [12] without capacity details.…”