Patent ID: 8908509

Claim:
A method of operating an Internet Protocol (IP) routed communication network, the IP routed communication network comprising a plurality of network nodes including edge nodes at edges of the IP routed communication network, a plurality of communication links interconnecting the edge nodes, and at least one flow admission controller, the method comprising: detecting a change in network topology; re-determining determined paths for routing IP packets between the edge nodes of the IP routed communication network responsive to the change in the network topology, each re-determined path comprising at least one communication link; storing the re-determined paths as pre-configured paths; setting a first threshold for a predetermined traffic type for a first communication link of the plurality of communication links and a second threshold for the predetermined traffic type for a second communication link of the plurality of communication links; monitoring bandwidth allocated to flows of the predetermined traffic type on the first communication link and the second communication link; selecting, from the pre-configured paths, a selected path between a source edge node and a destination edge node for a new flow having the predetermined traffic type, the selected path comprising the first communication link; determining whether bandwidth required by the new flow added to monitored allocation of bandwidth for the predetermined traffic type on the first communication link would exceed the first threshold for the predetermined traffic type on the first communication link; and indicating that the new flow would push usage beyond the first threshold for the predetermined traffic type when it is determined that admittance of the new flow would push the usage beyond the first threshold for the predetermined traffic type on the first communication link.