The INIM system: in-service non-intrusive monitoring for QoS-enabled transparent WDM

This paper presents the design and experimental implementation of an in-service performance monitoring system that uses a combination of non-intrusive spectral optical performance monitoring and Internet protocol (IP) metrics and is based on a low-complexity, distributed architecture. Apart from guaranteeing QoS in real time (less than 1 s) in an IP/wavelength-division-multiplexing (WDM) dynamic network, the system provides link-state information for impairment-aware routing and wavelength assignment. Another novel aspect is the nature of the service level agreements proposed, which are "all-optical" (transparent). Performance delays of the system are evaluated in a real test bed featuring dense WDM and transparent optical add-drop multiplexers. Strategies to estimate link-state parameters from real-time monitoring information are also proposed