For a fixed type of Petri nets τ , τ -SYNTHESIS is the task of finding for a given transition system A a Petri net N of type τ (τ -net, for short) whose reachability graph is isomorphic to A if there is one. The decision version of this search problem is called τ -SOLVABILITY. If an input A allows a positive decision, then it is called τ -solvable and a sought net N τ -solves A. As a well known fact, A is τ -solvable if and only if it has the so-called τ -event state separation property (τ -ESSP, for short) and the τ -state separation property (τ -SSP, for short). The question whether A has the τ -ESSP or the τ -SSP defines also decision problems. In this paper, for all b ∈ N, we completely characterize the computational complexity of τ -SOLVABILITY, τ -ESSP and τ -SSP for the types of pure b-bounded Place/Transition-nets, the b-bounded Place/Transitionnets and their corresponding Z b+1 -extensions.