Nokia Solutions and Networks Oy

Nokia of America Corporation

Andrew W Stone

Hooman Bidgoli

Felix Katz

Ehsan Rezaaifar

Attaullah Zabihi-Seissan

A controller includes a transceiver to establish a first session with a route reflector and monitor advertisements received by the route reflector from nodes in a network via second sessions established between the nodes and the route reflector. The controller also includes a processor to generate forwarding instructions for the nodes based on the advertisements. The forwarding instructions indicate one or more routes from a root node to one or more leaf nodes of a service. The transceiver provides the forwarding instructions to the root node. In some cases, the first session is established according to the border gateway protocol (BGP) and the one or more second sessions are established according to the BGP. The controller determines that the one or more leaf nodes are registered for one or more virtual private network (VPN) services based on the advertisements.

Configuring routes based on passive monitoring of advertisements to route reflector

Various example embodiments for supporting packet routing in a communication system may be configured to, in a communication network, support use of primary routing paths for routing traffic in the communication network and use of controller provided protection paths configured to protect the primary paths based on rerouting of traffic around failures in the communication network. Various example embodiments for supporting packet routing in a communication system may be configured to support controller provided protection paths in a communication network based on use of path control capabilities in which a network controller computes paths for a network and configures the paths in the network based on configuration of the paths on nodes of the network and based on routing capabilities in which the nodes use the routing paths for routing of traffic (e.g., via primary paths) and rerouting of traffic (e.g., via controller provided protection paths).

Controller provided protection paths

A processor generates an abstract topology that represents domains in an actual topology of a network and border routers that interconnect the domains in the actual topology. The processor prunes, based on the abstract topology, one or more of the domains from the actual topology during path calculations on the actual topology. In some cases, the processor determines measures of reachability for the nodes to indicate whether the domains represented by the nodes represent are on a path from a source domain to a destination domain. The processor can then selectively prune a relationship to at least one edge in the actual topology or modify weights of edges between the nodes in the actual topology based on the ranks of the nodes in the abstract topology.

Interdomain path calculation based on an abstract topology

This disclosure generally discloses a bidirectional constrained path search mechanism. The bidirectional constrained path search mechanism may be configured to determine bidirectional paths between a pair of nodes, subject to one or more constraints, such that the bidirectional paths share a common set of resources. The bidirectional constrained path search mechanism may be configured to determine bidirectional paths between a pair of nodes, subject to one or more constraints, by determining a forward path that satisfies a set of forward path constraints associated with the forward path and determining a reverse path that satisfies a set of reverse path constraints associated with the reverse path. The bidirectional constrained path search mechanism may be configured to determine bidirectional paths between a pair of nodes in a single path search iteration, such as via a traversal of a weighted directed graph, thereby improving performance.

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Ottawa, Canada

Andrew W Stone