Control Plane for Optical Networks: The ASON Approach

The paper gives a tutorial overview of the automatically switched optical network (ASON), concentrating on its control plane. Drivers to automatically switched optical networks are briefly presented. The ASON architecture, based on transport, control, and management planes is discussed. Types of connections supported by ASON are described, including permanent, switched, and soft permanent connections. Different kinds of internal and external interfaces are presented and discussed. Various issues related to the ASON control plane, such as control plane requirements, modeling, and functions are covered. These functions include: discovery, routing, signaling, call and connection control, as well as survivability mechanisms.