Node wrappers for QoS monitoring in transparent optical nodes

Transparent optical nodes (TONs), such as all-optical switches and erbium-doped fiber amplifiers, are an increasingly important part of wavelength-division multiplexed (WDM) networks. Our goal in this paper is to consider how quality of service (QoS) may be monitored at such TONs. The question is particularly important as access to WDM networks, and associated security concerns, increase. Our paper has four parts. First, we present an overview of the vulnerabilities of TONs to QoS degradation for two main classes of TONs, namely alloptical switching nodes and amplifiers in optical networks. Second, we discuss the applicability of traditional supervisory methods to such degradations. Third, we propose a novel approach to monitoring QoS degradations in TONs. Our approach works by comparing the input and output at a node and deciding whether unacceptable service degradation has occurred at that node. Finally, we analyze the performance, under simple attack scenarios, of our approach for jamming attacks at transparent optical switching nodes and amplifiers. We show that our method is several orders of magnitude faster than bit error rate testers in detecting QoS degradations.