Patent ID: 7490165

Claim:
A device for computing circuit paths between a first node and a second node within a network, the network including a plurality of elements which includes a protected link, the device comprising: a memory; a route generator, the route generator being arranged to generate a primary circuit path between the first node and the second node, the primary circuit path including a first element and a set of elements selected from the plurality of elements, wherein the route generator is configurable to selectively generate a nodal diverse alternate circuit path when a nodal diverse constraint is input and a link diverse alternate circuit path when a link diverse constraint is input, the input further being arranged to specify circuit characteristics for the primary circuit path and for the alternate circuit path; and a list mechanism, the list mechanism being stored in the memory, wherein the route generator is further arranged to generate an alternate circuit path between the first node and the second node using the list mechanism and the input, the list mechanism being arranged to identify the first element, the set of elements and the protected link as being inaccessible for use in subsequently generating the alternate circuit path, wherein the alternate circuit path does not include the first element, the set of elements and the protected link identified by the list mechanism.