Dorsal networks can be built to guarantee the availability of all the descriptions registered in a donantonio network:
network of servers in which is always possible to locate any given resource registered in Donantonio.
donantonio's server which is part of the network's Dorsal.
donantonio's server which replies only a part of the descriptions that keeps the dorsal of the donantonio's network, and therefore, it cannot be part of this dorsal.