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,