A method (200; 300) for establishing communication routes between nodes (106 0 ...106 63 ) of a computer cluster comprising: - nodes (106 0 ...106 63 ), - an interconnection network of the nodes (106 0 ...106 63 ) comprising: • switches (112 1 ...112 14 ) to a part of which the nodes (106 0 ...106 63 ) are connected, • communication links between the switches (112 1 ...112 14 ), the computer cluster having a certain topology defining the relative arrangement of the nodes (106 0 ...106 63 ), switches (112 1 ...112 14 ) and communication links , the method (200; 300) comprising the steps of: - obtaining the topology of the computer cluster , with first global numbers respectively assigned to the nodes (106 0 ...106 63 ), - implementing , for each pair of nodes (106 0 ...106 63 ), an algorithm designed for providing a communication route between the first and second nodes of the pair, based on respective numbers of these nodes and the topology of the computer cluster , the algorithm being designed for passing routes via the same communication link , the first or second nodes of which routes have periodic numbers according to a periodicity greater than one, characterized in that it further comprises: - selecting nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ), - numbering the nodes (106 0 ...106 63 ) in order to assign second global numbers thereto, which numbers are different from the first global numbers for at least one part of the selected nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ), the second global numbers of the selected nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ) being successively separated by values each of which is different from the periodicity of each of at least one part of the communication links , and in that , in order to implement the algorithm, the nodes (106 0 ...106 63 ) are identified by the second global numbers thereof. - nodes (106 0 ...106 63 ), - an interconnection network of the nodes (106 0 ...106 63 ) comprising: • switches (112 1 ...112 14 ) to a part of which the nodes (106 0 ...106 63 ) are connected, • communication links between the switches (112 1 ...112 14 ), • switches (112 1 ...112 14 ) to a part of which the nodes (106 0 ...106 63 ) are connected, • communication links between the switches (112 1 ...112 14 ), - obtaining the topology of the computer cluster , with first global numbers respectively assigned to the nodes (106 0 ...106 63 ), - implementing , for each pair of nodes (106 0 ...106 63 ), an algorithm designed for providing a communication route between the first and second nodes of the pair, based on respective numbers of these nodes and the topology of the computer cluster , the algorithm being designed for passing routes via the same communication link , the first or second nodes of which routes have periodic numbers according to a periodicity greater than one, - selecting nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ), - numbering the nodes (106 0 ...106 63 ) in order to assign second global numbers thereto, which numbers are different from the first global numbers for at least one part of the selected nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ), the second global numbers of the selected nodes (106 7 , 106 15 , 106 23 , 106 31 , 106 39 , 106 47 , 106 55 , 106 63 ) being successively separated by values each of which is different from the periodicity of each of at least one part of the communication links , <EOS>