Abstract: Illustrative embodiments provide an efficient, resilient high-availability (“HA”) router architecture. In illustrative embodiments, metric and event data is made resilient to node failover by replication. The same data is stored on the database of each router. Instead of pushing metrics directly from all of each node's software to each node's database, replication is instead handled by the database loader application subscribing to queues on both nodes. In some embodiments, records are written in the queues to topics that have a certain time to live (TTL), so the loader on one node has the duration of the TTL to read from the other node's queue in order to achieve replication.

Abstract: A method and apparatus for routing a plurality of session packets across a network toward a destination modifies each packet to include a sequence number that is different from the sequence number of other packets in the plurality of packets. Accordingly, at this point, each of the plurality of packets is transformed into a corresponding plurality of processed packets. The method also duplicates the plurality of processed packets to produce a corresponding plurality of duplicated packets. Next, the method forwards the plurality of processed packets toward the destination using a first stateful path through the network, and correspondingly forwards the plurality of duplicated packets toward the destination using a second stateful path through the network. In preferred embodiments, the first stateful path is different from the second stateful path. For example, the two paths may be entirely distinct in that they share no common intermediary elements.

Abstract: A router advertises an aggregated service or route that can be evaluated by other routers as a unitary segment rather than as a group of individual links/paths associated with the aggregated service or route. The aggregated service or route can be based on service and topology state information received from one or more other routers and can be advertised with the router as the nexthop for the aggregated service or route. The router can advertise an aggregated metric for the aggregated service or route for use in such evaluation. An aggregated route can be associated with different aggregated metrics for different services.

Abstract: A routing system for routing packets for a route or service comprises a plurality of routers including a source router, wherein the source router is configured to receive, using a service and topology exchange protocol, service and topology state information from a STEP repository for at least one other router based on configured relationships between routers; determine a first path to a destination for a route or service based on the service and topology state information, the first path including an ordered list of successive routers to receive a packet associated with the route or service starting with a first successive router and ending with a destination router; and transmit a packet toward the first successive router with first metadata including a list of at least one remaining router of the ordered list of routers to receive the packet associated with the route or service.

Abstract: One function of a communications network, or of nodes in such a network, is to gather data that is useful in assessing network performance, and quantifying metrics of node and/or network performance. Various embodiments disclosed herein improve the ability of nodes and networks to gather such data, and quantify metrics of node and/or network performance by selectively marking existing network traffic, and in preferred embodiments without having to dilute network traffic by generating and transmitting dummy data packets.

Abstract: In exemplary embodiments of the present invention, a router determines whether or not to establish a stateful routing session based on the suitability of one or more candidate return path interfaces. This determination is typically made at the time a first packet for a new session arrives at the router on a given ingress interface. In some cases, the router may be configured to require that the ingress interface be used for the return path of the session, in which case the router may evaluate whether the ingress interface is suitable for the return path and may drop the session if the ingress interface is deemed by the router to be unsuitable for the return path. In other cases, the router may be configured to not require that the ingress interface be used for the return path, in which case the router may evaluate whether at least one interface is suitable for the return path and drop the session if no interface is deemed by the router to be suitable for the return path.

Abstract: A routing system for distributing multicast routing information for a multicast service includes a plurality of routers including a multicast source router and a plurality of multicast receiver routers, the plurality of routers providing a multicast service, wherein the routers are configured to exchange multicast information associated with the multicast service including identification of multicast sources and the multicast receivers.

Abstract: A method routes packets from a source to a destination across an IP network having a plurality of nodes (including the source and destination), and a plurality of network segments interconnecting the plurality of nodes. The source and destination are configured to use a given service. To those ends, the method receives information relating to the given service, and forms a path between the source and the destination. The path includes a) at least one intermediate node between the source and the destination and b) a plurality of specific network segments extending from the source to the destination. The plurality of specific network segments are a sub-set of the plurality of network segments. To form the path, the method assigns the plurality of specific network segments to the network path between the source and the destination as a function of the information relating to the given service.

Abstract: A network device has an input configured to receive a message relating to a given device attempting to forward one or more packets across a computer network. The message has given device information relating to the given device. In addition, the routing device also has a selector, operatively coupled with the input, configured to select (after receiving the given data) a given group routing policy from a plurality of group routing policies. Preferably, the selector is configured to select the given group routing policy as a function of the given device information. The routing device also has an output operatively coupled with the selector. The output is configured to cause routing of device communication across the network using link-layer routes specified by the given group routing policy.

Abstract: A network device has an input configured to receive a message relating to a given user attempting to forward one or more packets across a computer network. The message has given user information relating to the given user. In addition, the routing device also has a selector, operatively coupled with the input, configured to select (after receiving the message) a given group routing policy from a plurality of group routing policies. Preferably, the selector is configured to select the given group routing policy as a function of the given user information. The routing device also has an output operatively coupled with the selector. The output is configured to cause routing of user communication across the network using link-layer routes specified by the given group routing policy.

Abstract: A method and apparatus form and/or define a network topology in a Layer 3 network with a plurality of nodes, where each node has at least one interface. To that end, the method defines a plurality of neighborhoods, and assigns at least one interface of each node to at least one of the neighborhoods. The method also assigns a communication role to each interface so that each communication role is effective relative to one of the plurality of neighborhoods. The method then enables communication between the interfaces of the plurality of nodes as a function of the neighborhoods and the communication roles.

Abstract: A method and apparatus for routing a plurality of session packets across a network toward a destination modifies each packet to include a sequence number that is different from the sequence number of other packets in the plurality of packets. Accordingly, at this point, each of the plurality of packets is transformed into a corresponding plurality of processed packets. The method also duplicates the plurality of processed packets to produce a corresponding plurality of duplicated packets. Next, the method forwards the plurality of processed packets toward the destination using a first stateful path through the network, and correspondingly forwards the plurality of duplicated packets toward the destination using a second stateful path through the network. In preferred embodiments, the first stateful path is different from the second stateful path. For example, the two paths may be entirely distinct in that they share no common intermediary elements.

Abstract: A routing system for implementing a service and topology exchange protocol (STEP) comprises a primary STEP server configured to maintain a STEP repository and a plurality of routers, each router including a STEP client in communication with the primary STEP server. The STEP client of each router is configured to transmit, using the service and topology exchange protocol, service and topology state information for at least one route or service available through the router to the primary STEP server for storage in the STEP repository.

Abstract: A routing system for routing packets for a route or service comprises a plurality of routers including a source router, wherein the source router is configured to receive, using a service and topology exchange protocol, service and topology state information from a STEP repository for at least one other router based on configured relationships between routers; determine a first path to a destination for a route or service based on the service and topology state information, the first path including an ordered list of successive routers to receive a packet associated with the route or service starting with a first successive router and ending with a destination router; and transmit a packet toward the first successive router with first metadata including a list of at least one remaining router of the ordered list of routers to receive the packet associated with the route or service.

Abstract: A network device has an input configured to receive a message relating to a given device attempting to forward one or more packets across a computer network. The message has given device information relating to the given device. In addition, the routing device also has a selector, operatively coupled with the input, configured to select (after receiving the given data) a given group routing policy from a plurality of group routing policies. Preferably, the selector is configured to select the given group routing policy as a function of the given device information. The routing device also has an output operatively coupled with the selector. The output is configured to cause routing of device communication across the network using link-layer routes specified by the given group routing policy.

Abstract: A network device has an input configured to receive a message relating to a given user attempting to forward one or more packets across a computer network. The message has given user information relating to the given user. In addition, the routing device also has a selector, operatively coupled with the input, configured to select (after receiving the message) a given group routing policy from a plurality of group routing policies. Preferably, the selector is configured to select the given group routing policy as a function of the given user information. The routing device also has an output operatively coupled with the selector. The output is configured to cause routing of user communication across the network using link-layer routes specified by the given group routing policy.

Abstract: A method and apparatus form and/or define a network topology in a Layer 3 network with a plurality of nodes, where each node has at least one interface. To that end, the method defines a plurality of neighborhoods, and assigns at least one interface of each node to at least one of the neighborhoods. The method also assigns a communication role to each interface so that each communication role is effective relative to one of the plurality of neighborhoods. The method then enables communication between the interfaces of the plurality of nodes as a function of the neighborhoods and the communication roles.

Abstract: A routing system for implementing a service and topology exchange protocol (STEP) includes a primary STEP server configured to maintain a STEP repository and a plurality of routers, with each router including a STEP client in communication with the primary STEP server. The STEP client of each router is configured to transmit, using STEP, STEP documents containing service and topology state information for at least one route or service available through the router to the primary STEP server for storage in the STEP repository. The primary STEP server is configured to transmit to the STEP client of each router, using STEP, service and topology state information from the STEP repository for at least one other router based on configured relationships between routers. Each router is configured to make routing decisions based at least in part on the service and topology state information from the at least one other router.

Abstract: In exemplary embodiments of the present invention, a router determines whether or not to establish a stateful routing session based on the suitability of one or more candidate return path interfaces. This determination is typically made at the time a first packet for a new session arrives at the router on a given ingress interface. In some cases, the router may be configured to require that the ingress interface be used for the return path of the session, in which case the router may evaluate whether the ingress interface is suitable for the return path and may drop the session if the ingress interface is deemed by the router to be unsuitable for the return path. In other cases, the router may be configured to not require that the ingress interface be used for the return path, in which case the router may evaluate whether at least one interface is suitable for the return path and drop the session if no interface is deemed by the router to be suitable for the return path.

Abstract: One function of a communications network, or of nodes in such a network, is to gather data that is useful in assessing network performance, and quantifying metrics of node and/or network performance. Various embodiments disclosed herein improve the ability of nodes and networks to gather such data, and quantify metrics of node and/or network performance by selectively marking existing network traffic, and in preferred embodiments without having to dilute network traffic by generating and transmitting dummy data packets.