Then G is the complete graph [K.sub.4] or the complete bipartite graph [K.sub.3,3] or the
3-cube [Q.sub.3].
5 shows an example of node migration in a 3-cube DCN.
Fig.6 shows an example of recovering multiple failures under a 3-cube DCN.
The eight
3-cubes of the graph have their eight nodes marked with a common letter.