Method and apparatus for computing a path through specified elements in a network

An apparatus for creating a path between a first element and a second element in an optical network, the path being arranged to include a third element, the apparatus comprising:

• a first means for identifying the third element;
• a second means for computing a path between the first element and the second element such that the path traverses the third element, wherein the first means identifies the third element as being a component of the path and identifies a fourth element as being a component of the path, the fourth element arranged to be traversed after the third element is traversed, the path being arranged to include plurality of segments, the second means being arranged to compute a first segment associated with the first element and the third element, the first segment being included in the plurality of segments;
• and
• a third means for substantially preventing the fourth element and the second element from being included in the first segment, wherein the second means computes a second segment associated with the fourth element, the second segment being included in the plurality of segments, and wherein the third mean substantially prevents the first element and the second element from being associated with the second segment.

An apparatus for routing a path between a source node and a destination node included within a network, the network further including a plurality of elements, the apparatus comprising:

• an identifier for identifying a set of elements to be included in the path, the set of elements being included in the plurality of elements;
• a blocker for blocking at least a first element included in the set of elements from being used in generating a first segment of the path, wherein the blocker blocks substantially all elements included in the set of elements except for the second element from being used in generating the first segment of the path;
• and
• a path router, the path router being arranged to generate the first segment such that the first segment includes the source node and a second element, the second element being included in the set of elements, wherein the first segment does not include the first element and the blocker is arranged to unblock the second element after the first segment is generated and to block at least one element included in the plurality of elements from being included in a second segment of the path, the at least one element included in the plurality of elements being a component of the first segment.

A method for computing a circuit path between a source node and a destination node of an optical network, the method comprising:

• identifying at least a first element that is to be traversed by the circuit path between the source node and the destination node;
• identifying a second element that is to be traversed by the circuit path between the first element and the destination node;
• blocking the second element from being available for use in routing a first segment automatically;
• blocking the destination node from being available for use in routing the first segment automatically;
• routing the first segment automatically, the first segment being a part of the circuit path, wherein when the first element is a node, the source node and the first element are components of the first segment, routing the first segment automatically including routing the first segment automatically using a shortest path first algorithm to substantially avoid including the second element as a component and substantially avoiding including the destination node as a component;
• unblocking the second element such that the second element is available for use in routing a second segment automatically, the second segment being a part of the circuit path;
• blocking the source node from being available for use in routing the second segment automatically;
• and
• routing the second segment automatically, wherein the second element is a component of the second segment and the source node is not a component of the second segment.

A computer program product:

• computer code that causes at least a first element that is to be traversed by the circuit path between the source node and the destination node to be identified;
• computer code that causes a second element that is to be traversed by the circuit path between the first element and the destination node to be identified;
• computer code that causes the second element to be blocked from being available for use in routing a first segment;
• computer code that causes the destination node to be blocked from being available for use in routing the first segment;
• computer code that causes the first segment to be routed, the first segment being a part of the circuit path, wherein when the first element is a node, the source node and the first element are components of the first segment, the computer code that causes the first segment to be routed including computer code that causes the first segment to be routed using a shortest path first algorithm and computer code that causes the first segment to be routed to substantially avoid including, the second network element as a component and to substantially avoid including the destination node as a component;
• computer code that causes the second element to be unblocked such that the second element is available for use in routing a second segment, the second segment being a part of the circuit path;
• computer code that causes the source node to be blocked from being available for use in routing the second segment;
• computer code that causes the second segment to be routed, wherein the second element is a component or the second segment and the source node is not a component of the second segment;
• and
• a computer-readable medium that stores the computer codes.