What is Lightpath

Internet protocol (IP) over optical (IP-over-optical) networks is the widely accepted solution to meet the ever increasing demands of IP traffic. In an IP-over-optical network, the IP routers are attached to an optical core network, composed by optical cross-connects (OXC) that are interconnected by dynamically established optical wavelength channels called lighpaths (Rajagopalan, Pendarakis, Saha, Ramamoorthy, & Bala, 2000). To control such lightpaths in a dynamic, efficient, and realtime manner, generalized multiprotocol label switching (GMPLS) based control plane has been proposed by the Internet engineering task force (IETF) in the RFC 3945 edited by Mannie (2003).