This case study outlines a project undertaken by Fiber Optic Sensing Solutions Pvt Ltd (FOSS) to implement an Intrusion Detection Solution at an electric substation. The project objectives included providing 24×7 intrusion alerts, integrating the solution with the existing VMS, and maintaining a. This case study highlights an application where fiber was used with an optical sensor to monitor intrusion in critical infrastructure operated by a public services utility. A water company in Europe had optical cable installed along their pipeline network in order to provide internal data services. Indianapolis Power & Light Company (IPL) provides retail electric service to more than 470,000 residential, commercial and industrial customers in Indianapolis, Indiana. IPL maintains a vast network of underground infrastructure and power cables throughout downtown Indianapolis which are subject to. Monitoring Critical Infrastructure with Optical Fiber Sensors and the ONMSi Accurately detecting intrusion, open access points, and thefts Fiber networks are best known for enabling high-speed data communications. However, since optical fibers are bend-sensitive, especially at certain wavelengths. All these applications run on a robust 120 Km Optical Fibre backbone and an MPLS network with an advanced CCC comprising a highly sophisticated data center network.