Abstract: In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.

Abstract: In an embodiment, a method comprises: receiving, at a data packet router, a path advertisement comprising information about an available path; determining whether the path advertisement comprises an originator identifier of an originator of the available path; in response to determining that the path advertisement comprises the originator identifier of the originator of the available path, determining whether the originator identifier of the available path is a router identifier of the data packet router, and in response to determining that the originator identifier of the available path is the router identifier of the data packet router, not accepting the path advertisement; wherein the method is performed by one or more processors of the data packet router.

Abstract: In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.

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: 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: In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.

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 and 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.

Abstract: In one embodiment, a primary tail-end node (PTE) of a point-to-multipoint (P2MP) tunnel selects a backup tail-end node (BTE) from one or more BTEs that are configured to forward traffic to a same multicast network as the PTE. The PTE then determines a branching node of the P2MP tunnel to reach the PTE and the selected BTE, and notifies the branching node of the selected BTE. In response, the branching node establishes a backup tunnel to the selected BTE, and redirects P2MP traffic onto the backup tunnel to the selected BTE in response to a detected failure of the PTE.

Abstract: In an embodiment, a method comprises: receiving, at a data packet router, a path advertisement comprising information about an available path; determining whether the path advertisement comprises an originator identifier of an originator of the available path; in response to determining that the path advertisement comprises the originator identifier of the originator of the available path, determining whether the originator identifier of the available path is a router identifier of the data packet router, and in response to determining that the originator identifier of the available path is the router identifier of the data packet router, not accepting the path advertisement; wherein the method is performed by one or more processors of the data packet router.

Abstract: In one embodiment, a primary head-end node (PHE) and one or more backup head-end nodes (BHEs) receive traffic from a common multicast network. The PHE establishes a primary point-to-multipoint (P2MP) tunnel and forwards the multicast traffic onto the primary P2MP tunnel. The PHE then notifies a selected BHE of one or more characteristics of the primary P2MP tunnel, and the selected BHE establishes a backup P2MP tunnel with the characteristics of the primary P2MP tunnel. In response to detecting a failure of the PHE, the BHE initiates forwarding of the multicast traffic onto the backup P2MP tunnel.

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 and 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.

Abstract: In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.

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 and 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.

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 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 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: In one embodiment, a primary head-end node (PHE) and one or more backup head-end nodes (BHEs) receive traffic from a common multicast network. The PHE establishes a primary point-to-multipoint (P2MP) tunnel and forwards the multicast traffic onto the primary P2MP tunnel. The PHE then notifies a selected BHE of one or more characteristics of the primary P2MP tunnel, and the selected BHE establishes a backup P2MP tunnel with the characteristics of the primary P2MP tunnel. In response to detecting a failure of the PHE, the BHE initiates forwarding of the multicast traffic onto the backup P2MP tunnel.

Abstract: In one embodiment, a primary tail-end node (PTE) of a point-to-multipoint (P2MP) tunnel selects a backup tail-end node (BTE) from one or more BTEs that are configured to forward traffic to a same multicast network as the PTE. The PTE then determines a branching node of the P2MP tunnel to reach the PTE and the selected BTE, and notifies the branching node of the selected BTE. In response, the branching node establishes a backup tunnel to the selected BTE, and redirects P2MP traffic onto the backup tunnel to the selected BTE in response to a detected failure of the PTE.

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.