This paper addresses the structural optimization of a next generation optical, lattice based, yottabit-per-second transport network topology, called the YottaWeb [1,2,3]. One of the key issues for this type of structure is to assess what is the number of agile cores that each edge node has to be attached to. This is what is called the dimension of the structure. In this article, several optimization metrics are explored and it is found that the optimal solution corresponds to a structure of dimension two.