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 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: 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 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: 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 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 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 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 providing multicast access control 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 enforce multicast access control policies for the multicast service including a receiver access policy that controls which multicast receivers are allowed to receive packets from the multicast service and a sender access policy that controls which multicast sources are allowed to send packets to the multicast service for distribution to the multicast receivers.

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 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 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 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 providing multicast access control 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 enforce multicast access control policies for the multicast service including a receiver access policy that controls which multicast receivers are allowed to receive packets from the multicast service and a sender access policy that controls which multicast sources are allowed to send packets to the multicast service for distribution to the multicast receivers.

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: 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 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 packet routing method and apparatus for managing packets of a bi-directional session between a first node and a second node in an IP network receives a mid-stream packet at an intermediate node. The intermediate node is not part of the bi-directional session. Next, the method identifies the bi-directional session (“identified session”) from which the mid-stream packet originated. The identified session includes a bi-directional path between the first node and the second node, while the bi-directional path includes a plurality of nodes for bi-directionally forwarding packets between the first node and the second node. The method then directs that one or more packets of the identified session be routed to at least one of the plurality of nodes of the identified session.

Abstract: An intermediate node obtains a lead packet of a plurality of packets in a session having a unique session identifier, modifies the lead packet to identify at least the intermediate node and also to identify source and destination port numbers assigned by the intermediate node for a possible forward association, and then forwards the lead packet toward the destination node though an intermediate node electronic output interface to the IP network. The intermediate node also may receive, through an intermediate node electronic input interface in communication with the IP network, a backward message from a next node having a next node identifier. Both the intermediate node and the next node form an association between the intermediate node identifier, the next node identifier, and the source and destination port numbers assigned by the intermediate node. This association is part of a forward association for the intermediate node and is part of a return associate for the next node.