In recent literature, increasing experimental and numerical e ort has been de- voted to understanding and predicting the behavior of glassy systems. Among those classes of materials, of particular relevance are network glasses. In such system the composing particles can form a small number of bonds with their neighbors, leading then to an overall network structure. Among everyday mate- rials, common window glass is perhaps the most obvious example of a network glass, but many others have, on the microscopic scale, a disordered network structure. To better understand these materials, it is of primary importance to gure out the role and the local organization of the bonds in the network structure.