Patent ID: 7636302

Claim:
A method for avoiding unnecessary preemption of resource reservations along a requested flow between nodes in a computer network, the method comprising: maintaining a held resources state at a node, the held resources state indicating that resources of the node are held for path request messages prior to their being reserved by resource reservation requests; receiving at the node a first path request message for a first flow in a first direction indicating requested resources; calculating the amount of available resources at the node, the calculation including resources that are held at the node; comparing the requested resources to the amount of available resources at the node; determining that conditions of reservation eligibility are met when the requested resources are less than or equal to the amount of available resources; receiving a first resource reservation request for the first flow at a sender of the first flow; receiving a second path request message at the sender of the first flow, the second path request message for a second flow in a second direction, the second path request message having an indication of a likelihood of success of the second flow based upon a determination of whether conditions of reservation eligibility are met for the second flow; and returning, from the sender of the first flow, a first reservation confirmation message for the first flow after receiving both the first resource reservation request and the second path request message, where the second path request message indicates success for the second flow.