IP over optical networks: Architectural aspects

The Internet transport infrastructure is moving toward a model of high-spee d routers interconnected by intelligent optical core networks. A consensus is emerging in the industry on utilizing an IP-centric control plane within optical networks to support dynamic provisioning and restoration of lightp aths. At the same time, there are divergent views on how IP routers must in teract with optical core networks to achieve end-to-end connectivity. This article describes the architectural alternatives for interconnecting IP rou ters over optical networks, considering the routing and signaling issues. A lso, the application of IF-based protocols for dynamic provisioning and res toration of lightpaths, as well as the interworking of multivendor optical networks is described.