Method for efficiently retrieving topology-specific data for point-to-point networks

1. In one or more computers, a method of providing topology-specific data for a given point-to-point network, comprising:

pre-computing by one or more of the computers and making available topology-specific data for each one of a plurality of selected point-to-point networks;

calculating by one or more of the computers and making available, for each one of the plurality of selected point-to-point networks having a respective unique topology, a respective unique associated topology code that uniquely identifies the topology of that selected point-to-point network, wherein the associated topology code for each selected point-to-point network is calculated by:

applying, to a graph representing the selected point-to-point network, a node-ordering algorithm that produces a set of node orderings;

using the set of node orderings to produce adjacency matrices for the selected point-to-point network;

using the adjacency matrices to produce candidate topology codes; and

selecting, from the candidate topology codes, a topology code with a maximum value as the key for the selected point-to-point network;

calculating by one or more of the computers a topology code for the given point-to-point network;

using the calculated topology code for the given point-to-point network as a key to look up the pre-computed topology-specific data for any of the plurality of selected point-to-point networks for which the associated topology code is identical to the topology code for the given point-to-point network; and

retrieving the looked-up pre-computed topology-specific data for the given point-to-point network.

2. The method of claim 1 wherein the topology-specific data includes an optimal routing matrix.

3. The method of claim 1 wherein the topology-specific data includes performance statistics.

4. The method of claim 1 wherein the topology-specific data is made available by being cached.

5. The method of claim 1 wherein, for each selected point-to-point network, the associated topology code has a number B of significant bits and the selected network has a number N of nodes which are related by the formula B=N(N−1)/2.

6. The method of claim 1 wherein each calculated topology code contains all information necessary to reconstruct a graph that is isomorphic to all other graphs having the same topology code.

7. The method of claim 1 including testing whether a given point-to-point network and a selected point-to-point network are isomorphic to each other by comparing their topology codes.