ASTN
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An Automatically Switched Transport Network is a network that can automatically manage the signalling and routing of a network. Traditionally, it was necessary to configure cross-connections in the Network Elements (such as an optical switch) to create a new traffic path for a customer.
In an ASTN, this process can be automated. The customer defines a new path by its start and end point, the bandwidth needed, the Quality of Service and so on. The Network Elements have the necessary processing functions, in the form of an ASTN agent, built in to configure the new traffic path. The path itself is not specified by the customer. The ASTN agents can re-route the traffic path if the network is changed.
ASTN uses the Generalized MPLS signalling protocol to set up and monitor edge-to-edge transport connections. ASTN concentrates on SDH/SONET rings in the access networks and metropolian area networks, so called city rings. The related ASON (Automatically Switched Optical Network) focuses on the optical backbone network that connects these city rings.
ASTN is defined in ITU Recommendation G.807. This recommendation is previously known as G.ASTN.