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: Techniques are disclosed for session-based routing within Open Systems Interconnection (OSI) Model Layer-2 (L2) networks extended over Layer-3 (L3) networks. In one example, L2 networks connect a first client device to a first router and a second client device to a second router. An L3 network connects the first and second routers. The first router receives, from the first client device, an non-session-based L2 frame destined for the second client device. The first router forms an L3 packet comprising an L3 header specifying L3 addresses of the first and second routers and a protocol selected based on an L3 service for the L2 frame, a payload comprising the L2 frame, and metadata comprising a session identifier distinctly identifying the L2 frame, and forwards the L3 packet to the second router. The second router recovers the L2 frame from the payload and forwards the L2 frame to the second client device.

Abstract: Techniques are disclosed for session-based routing of multipoint Open Systems Interconnection (OSI) Model Layer-2 (L2) frames of an L2 network extended over Layer-3 (L3) networks. In one example, L2 networks connect a source device to an ingress router and receiver devices to egress routers. An L3 network connects the ingress and egress routers. The ingress router receives, from the source device, a multipoint L2 frame destined for the receiver devices. The ingress router forms, for each egress router that is connected to at least one multipoint receiver device, a unicast L3 packet for the L2 frame and forwards the unicast L3 packet to the egress router. Each egress router generates, in response to receiving the unicast L3 packet, the multipoint L2 frame and forwards, to the receiver devices, the multipoint L2 frame.

Abstract: Techniques are disclosed for session-based routing within Open Systems Interconnection (OSI) Model Layer-2 (L2) networks extended over Layer-3 (L3) networks. In one example, L2 networks connect a first client device to a first router and a second client device to a second router. An L3 network connects the first and second routers. The first router receives, from the first client device, an L2 frame destined for the second client device. The first router generates an L3 packet comprising an L3 header specifying L3 addresses of the first and second routers, a first portion of metadata comprising L2 addresses for the first and second client devices, and a second portion of metadata comprising L3 addresses for the first and second client devices, and forwards the L3 packet to the second router. The second router recovers the L2 frame from the metadata and forwards the L2 frame to the second client device.

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: 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 first router generates session establishment metrics for use in network path selection. For example, a plurality of routers connect a client device to a network service instance hosted by a server. A first router is connected to the network service instance via first and second paths. The first router receives session performance requirements for a session between the client device and the network service instance. The first router forwards, along the first path, network traffic for the session by modifying a first packet of the session to include a session identifier for the session. The first router determines that session establishment metrics for the session do not satisfy the session performance requirements. In response, the first router forwards, along the second path, the network traffic for the session by modifying a second packet of the session to include the session identifier for the session.

Abstract: A network device is configured to associate a tenant of a plurality of tenants with a virtual routing and forwarding (VRF) instance of a plurality of VRF instances. The network device receives a packet comprising metadata specifying a tenant identifier for the tenant. The network device identifies, based on the tenant identifier specified by the metadata, the VRF instance associated with the tenant. The network device retrieves one or more routes from a routing information base (RIB) of the VRF instance associated with the tenant and forwards the packet toward a destination via the one or more routes.

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: 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: 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 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: Routing packets by a router involves establishing a first flow configured for forwarding the packets from a first ingress interface to a first egress interface of the router; determining a condition to modify the first flow; deactivating the first flow; establishing a second flow configured for forwarding the packets from at least one of (1) the first ingress interface to a second egress interface, (2) a second ingress interface to the first egress interface, or (3) a second ingress interface to a second egress interface; and activating the second flow.

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: 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.