Capacity-aware local repair of tunnels in wide area networks

Abstract

Solutions are disclosed that enable capacity-aware local repair of tunnels in packet switched wide area networks (WANs). Traffic engineering agents on the routers are programmed to create the tunnels and include sets of primary and alternate tunnels sharing the same source and destination. A tunnel source router is provided a traffic split for allocating incoming traffic to its primary and alternate tunnels for when the primary tunnel is operating at or near full capacity operation, and another traffic split that shifts at least some traffic from the primary tunnel to the alternate tunnel, when the primary tunnel's capacity drops below a threshold. A tunnel may lose capacity for commonly-occurring reasons, such as a disturbance to cabling and faults in optical transceivers. Traffic engineering agents along the tunnel report capacity to the tunnel source router, permitting the network to respond to capacity changes more rapidly than waiting for network tunnel reconfiguration.