The central question here is to design a VP-ATM network which offers VP connections with different protection levels. The users should have the choice of selecting the protection grade they need at call set-up time. Availability classes are defined. Each class corresponds to a set of failure scenarios for which a restoration guarantee is provided. Besides, the bigger the failure scenarios set of a class is, the higher the availability provided, and the higher the priority in the network concerning VP rate assignment. Each availability class constitutes a virtual (logical) VP-subnetwork on top of a large ATM network. Given the traffic demand for each availability class, we are searching for the partition of the (physical) transmission capacities (among the different availability classes) that maximises the total carried traffic. This partition is dynamically changed in response to changing traffic demand.

[PS] [PS.GZ]