automatically switched transport network (ASTN)
In concept, an Automatically Switched Transport Network (ASTN) is comparable to an Automatically Switched Optical Network( ASON).
The difference between ASTN and ASOn is that ASTN is used in Metropolian Area Networks( MAN) and Access Networks( AN), whereas ASON is used in the optical core network. As with ASON networks, the user defines the link endpoint and transmission parameters for ASTN networks, and the network automatically selects the optimal path. Both network concepts have automatic routing and use the GMPLS protocol for signaling.
ASTN is described in ITU Recommendation G.807.