Neighborhood Failure Localization in All-Optical Networks via Monitoring Trails

Abstract

Abstract-Shared protection, such as failure dependent protection (FDP), is well recognized for its outstanding capacity efficiency in all-optical mesh networks, at the expense of lengthy restoration time due to multi-hop signaling mechanisms for failure localization, notification, and device configuration. This paper investigates a novel monitoring trail (m-trail) scenario, called Global Neighborhood Failure Localization (G-NFL), that aims to enable any shared protection scheme, including FDP, for achieving all-optical and ultra-fast failure restoration. We firstly define neighborhood of a node, which is a set of links whose failure states should be known to the node in restoration of the corresponding working lightpaths (W-LPs). By assuming every node can obtain the on-off status of traversing m-trails and W-LPs via lambda monitoring, the proposed G-NFL problem routes a set of m-trails such that each node can localize any failure in its neighborhood. Bound analysis is performed on the minimum bandwidth required for m-trails under the proposed G-NFL problem. Then a simple yet efficient heuristic approach is presented. Extensive simulation is conducted to verify the proposed G-NFL scenario under a number of different definitions of nodal neighborhood which concern the extent of dependency between the monitoring plane and data plane. The effect of reusing the spare capacity by FDP for supporting m-trails is examined. We conclude that the proposed G-NFL scenario enables a general shared protection scheme, toward signaling-free and ultra-fast failure restoration like p-Cycle, while achieving optimal capacity efficiency as by FDP.

Unambiguous switching link group failure localization in all‐optical networks

“…In order to improve these drawbacks of NWL‐UFL, Global Neighborhood Failure Localization (G‐NFL) has been proposed in . The main idea is to unambiguously localize only a small set of link failures that particular node needs to respond to in the restoration process via short m‐trails.…”

“…In order to enable fast failure localization in all‐optical networks, supervisory lightpaths (S‐LP, monitoring trails or m‐trails) have been introduced . An m‐trail consists of a pair of lightpaths along a common physical route (in opposite directions), and is purely used for monitoring the on/off status of the physical links along the route at the end‐nodes.…”

“…Furthermore, if each traversed node is able to monitor the status of a carefully allocated set of m‐trails via lambda monitoring, failure notification time could be reduced to minimal as well, because each node can perform protection switching immediately without waiting for failure notification messages, purely based on local observations. Thus, S‐LPs enable the recovery of an arbitrary shared protection scheme to be performed completely signaling‐free .…”

“…The goal of previous m‐trail allocation methods was unambiguous localization of single link failures to support both protection switching and link maintenance , that is, each link failure has to correspond to a different set of alarms/disrupted m‐trails. We argue that this strict requirement is only mandatory for link maintenance; hence, it often leads to an unnecessary amount of S‐LP transponders and wavelength links for protection switching.…”

BER Degradation Detection and Failure Identification in Elastic Optical Networks

“…Regarding failure localization, several works in the literature have proposed methods for localization of hard link failures that affect a number of established connections, focused on reducing restoration times (see, e.g., [19]- [21]). All the proposed methods basically consist on computing and establishing a number of auxiliary connections (m-trails or mcycles).…”