Abstract: Various devices and methods for implementing multicast over a label-switched core network are disclosed. For example, an edge node can include a physical interface, which is not enabled for multicast, that is configured to be coupled to a core network and a packet rewrite module coupled to the physical interface. The packet rewrite module is configured to encapsulate a multicast packet with a label and to send the encapsulated multicast packet to the physical interface. The label identifies a unicast label switched path (LSP) through the core network. The edge node can also include a virtual interface creation configured to create a virtual interface that is enabled for multicast. The packet rewrite module can encapsulate the multicast packet in response to detecting that the multicast packet is being sent via the virtual interface.

Abstract: A technique dynamically determines whether to reestablish a Fast Rerouted primary tunnel based on path quality feedback of a utilized backup tunnel in a computer network. According to the novel technique, a head-end node establishes a primary tunnel to a destination, and a point of local repair (PLR) node along the primary tunnel establishes a backup tunnel around one or more protected network elements of the primary tunnel, e.g., for Fast Reroute protection. Once one of the protected network elements fail, the PLR node “Fast Reroutes,” i.e., diverts, the traffic received on the primary tunnel onto the backup tunnel, and sends notification of backup tunnel path quality (e.g., with one or more metrics) to the head-end node. The head-end node then analyzes the path quality metrics of the backup tunnel to determine whether to utilize the backup tunnel or reestablish a new primary tunnel.

Abstract: A mechanism is provided to configure a plurality of transport trees in a transport network, each of which correspond to a native tree (e.g., a bidirectional multicast tree). In embodiments of the present invention, each of the plurality of transport trees has a unique root node so that in the event of a failure of any root node, the transport trees with surviving root nodes can be used to transport traffic from the native tree. The present invention provides for each transport network edge router being independently responsible for selection of a transport tree that the edge router will use to transmit a datastream, while also being capable of receiving packets from any transport tree. Through the use of such configured transport trees along with independent selection of a transport tree, the present invention provides a reduction in the disruption of datastream transmission due to a root node failure.

Abstract: A mechanism is provided in which multicast reverse path forwarding can be performed at a provider network egress edge router wherein core routers of the provider network are not configured to support multicast protocols or point-to-multipoint LSPs. An embodiment of the present invention provides for the creation of virtual interfaces in the egress edge router element during configuration of a multicast connection in response to a subscriber request. A virtual interface will be associated with an upstream ingress edge router element and that ingress edge router element is provided a label associated with the virtual interface. Such a label can then be included in datastream packets transmitted through the provider network. The label can then be used by reverse path forward checking at the egress edge router element to ascertain whether the multicast datastream is being received by the correct upstream interface (e.g., the virtual interface associated with the ingress edge router element).

Abstract: A method and system for providing QoS in a network after a network failure are disclosed. The network includes at least one primary tunnel and at least one backup tunnel protecting a segment of the primary tunnel. The method includes receiving notification of a failure within the primary tunnel segment and rerouting received packets onto the backup tunnel. The rerouted packets are marked to identify packets affected by the failure and are subject to a different QoS policy than packets that have not been rerouted due to the failure.

Abstract: A Fast Reroute implementation where switchover time to backup tunnels upon failure of a protected network element is independent of a number of entries corresponding to forwarding equivalence classes forwarding over LSPs using that element. During normal operation of a packet forwarding device, adjacency information for a received packet is retrieved from a forwarding table based on a look-up of the packet's forwarding equivalence class. Upon failure of a link or node, the appropriate entries in this forwarding table are rewritten to implement the switchover to preconfigured backup tunnels. The switchover is effective even before the rewrite process has completed. Upon detection of the failure, forwarding processing shifts to a fix-up mode. During the fix-up mode, the look-up to the previously mentioned forwarding table is followed by a look-up to a backup tunnel adjacency table based on a pointer retrieved from the forwarding table.