Abstract: Methods and network devices are disclosed for failure protection in traffic-engineered bit indexed explicit replication networks. In one embodiment, a method includes receiving at a node in a network a message comprising a message bit array, where bit positions in the message bit array correspond to respective links in the network. The method further includes evaluating a bit value at a bit position in the message bit array, where the bit position corresponds to a network link represented in a forwarding table for the node, checking for a failure state of the link represented in the forwarding table, and, responsive to a determination of a failure state of the link, modifying one or more bit values in the message bit array. In one embodiment a network device includes a network interface, a memory configured to store a forwarding table, and a processor configured to carry out the methods.

Abstract: Methods and network devices are disclosed for traversal, within a network configured for bit indexed forwarding, of a subnetwork having nodes not configured for bit indexed forwarding. In one embodiment, a method includes receiving, from a first network node not configured for bit indexed forwarding, a data message comprising a local label and a message bit array. Bit values in the message bit array identify intended destination nodes for the message. The embodiment further includes modifying the message bit array to exclude as intended destination nodes for the message any nodes not represented by one or more relative bit positions associated with the local label and stored in an ingress filter data structure. In addition, the embodiment includes forwarding a copy of the data message to a second network node, which is configured for bit indexed forwarding, identified in an accessed entry of a bit indexed forwarding table.

Abstract: Methods and network devices are disclosed for multicast traffic steering in a communications network. In one embodiment, a method includes generating a first tree connecting a source node for a multicast flow through a communications network to each of multiple destination nodes for the multicast flow. The communications network is configured to forward a multicast message based on bit values in a message bit array carried by the message, and the first tree comprises a first set of unicast paths from the source node to the destination nodes. The method further includes allocating a first tree identifier to the first tree and communicating the first tree identifier and associated forwarding information to each of multiple forwarding nodes within the communications network. An embodiment of a network device includes a processor operably coupled to one or more network interfaces and adapted to perform steps of the method.

Abstract: Methods and network devices are disclosed for internet protocol (IP) based encapsulation in bit indexed explicit replication (BIER) forwarding. In one embodiment, a method includes receiving a multicast message comprising an inner IP header, an intervening header, and an outer IP header. The embodiment further includes accessing a message bit array stored in the intervening header, retrieving an IP address from an entry in a bit indexed forwarding table, replacing an IP destination address in the outer IP header of a copy of the multicast message with the retrieved IP address, and sending the copy of the multicast message toward a second node in the network, where the retrieved IP address is assigned to the second node. An embodiment of a network device includes a processor operably coupled to a plurality of storage locations and to one or more network interfaces and adapted to perform steps of the method.

Abstract: Methods, devices and program instructions are disclosed for performing bit indexed explicit replication (BIER) including fast reroute capability. One embodiment of a method includes receiving, from an egress node of a BIER network, an advertisement at a forwarding node, where the advertisement identifies a mapping of the egress node to a bit position of a packet bit string to be carried by a packet through the network. The embodiment further includes generating or updating a primary entry for the egress node in a bit indexed routing table (BIRT) for the forwarding node, and determining whether a backup entry for the egress node is to be included in the BIRT. In response to a determination that a backup entry is to be included, the embodiment further includes generating or updating the backup entry in the BIRT.

Abstract: A method is provided in one example embodiment and may include determining at a parent content node that a plurality of recipient content nodes are to receive a same content; generating, based on a determination that the same content is available at the parent content node, a multi-delivery header comprising a plurality of identifiers, wherein each identifier of the plurality of identifiers indicates each recipient content node that is to receive the same content; appending the multi-delivery header to one or more packets of an Internet Protocol (IP) flow associated with the same content; and transmitting packets for the IP flow to each of the plurality of the recipient content nodes.

Abstract: In one embodiment, a method comprises creating, in a computing network, a loop-free routing topology comprising a plurality of routing arcs for reaching a destination network node; identifying, within the loop-free routing topology, non-congruent paths for a source network node to reach the destination node; and determining, from the non-congruent paths, a non-congruent path pair providing no more than a prescribed difference of latency from the source network node to the destination node, enabling the source network node to forward a data packet in a first direction of the one non-congruent path pair and a bicasted copy of the data packet in a second direction of the one non-congruent path pair, for reception of the data packet and the bicasted copy by the destination node within the prescribed difference of latency.

Abstract: A method and network device are disclosed for multicast forwarding. In one embodiment, the method includes receiving at a node configured to use a bit-indexed forwarding table a multicast message comprising an incoming message bit array. The method further includes comparing the incoming message bit array to a first neighbor bit array within a first forwarding table entry, and determining that for at least one relative bit position in the bit arrays a corresponding destination node is both a destination for the message and a reachable destination from a first neighboring node. The method further includes forwarding toward the first neighboring node a copy of the message, where a first node on the path of the forwarded message is not configured to use a respective bit-indexed forwarding table. An embodiment of the device includes a network interface, a memory and a processor configured to perform steps of the method.

Abstract: Various systems and methods for performing bit indexed explicit replication (BIER) using IPv6. For example, one method involves receiving, at a node, a packet that includes an IP header. The packet also includes a multicast forwarding entry. The method also involves comparing the multicast forwarding entry with forwarding information stored by the node and selecting a neighbor based on the comparing. The method further includes forwarding the packet to the neighbor.

Abstract: Various systems and methods for performing bit indexed explicit replication (BIER). For example, one method involves receiving a packet at a node. The packet includes a bit string includes information identifying a plurality of destinations. The node selects an entry in a bit indexed forwarding table (BIFT). The BIFT includes both a primary path entry and a backup path entry. The node forwards the packet based on information in the entry.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: In one embodiment, a device in a network sends a first multicast message to a plurality of destinations in the network. The first multicast message includes a first bitmap that identifies the destinations. The device receives one or more acknowledgements from a subset of the destinations. The device determines a retransmission bitmap that identifies those of the plurality of destinations that did not acknowledge the first multicast message, based on the received one or more acknowledgements. The device sends a retransmission multicast message to those of the plurality of destinations that did not acknowledge the first multicast message. The retransmission multicast message includes the retransmission bitmap.

Abstract: Methods and network devices are disclosed relating to a multi-area communication network employing bit indexed explicit replication (BIER). In one embodiment, a method includes receiving, at a node in a communications network, a message comprising a first message bit array. The method further includes detecting a bit value of a first relative bit position in the first message bit array, where the first relative bit position represents a first group of destination nodes in the communications network, and evaluating the bit value of the first relative bit position in order to determine whether to encapsulate the received message for delivery to the first group of destination nodes. An embodiment of a network device comprises a processor adapted to implement an embodiment of the method.

Abstract: Methods and network devices are disclosed for multicast forwarding. In one embodiment, a method includes receiving at a node a multicast message comprising a message header, where the message header comprises an incoming message bit array and a set identifier value associated with the incoming message bit array. The method further comprises selecting a first forwarding table entry, the first forwarding table entry comprises a set identifier value matching that of the message header. The method further comprises comparing at least a portion of the incoming message bit array to a corresponding portion of a neighbor bit array of the first forwarding table entry, determining that for at least one relative bit position a corresponding destination node is both a destination for the message and a reachable destination from a first neighboring node, and forwarding a copy of the message to the first neighboring node.

Abstract: Various systems and methods for performing bit indexed explicit replication (BIER) using IPv6. For example, one method involves receiving, at a node, a packet that includes an IP header. The packet also includes a multicast forwarding entry. The method also involves comparing the multicast forwarding entry with forwarding information stored by the node and selecting a neighbor based on the comparing. The method further includes forwarding the packet to the neighbor.

Abstract: Methods and network devices are disclosed for replication and switching of Internet Protocol (IP) packets in professional media networks. In one embodiment, a method includes encapsulating a unicast IP packet with a packet bit array and forwarding the encapsulated packet via a replication fabric within a network. In this embodiment, each receiver of a plurality of receivers reachable via the replication fabric is represented by a relative bit position in the packet bit array, a respective IP address is assigned to each receiver of the plurality of receivers, and the replication fabric is adapted to store disposition information mapping a relative bit position representing one or more of the plurality of receivers to IP addresses assigned to the one or more of the plurality of receivers. An embodiment of a network device includes a processor operably coupled to a network interface and adapted to perform steps of the method.

Abstract: Methods, devices and computer readable storage media for performing bit indexed explicit replication (BIER) are disclosed. One embodiment of a method includes receiving, at an ingress node of a network, a data packet comprising a multicast group identifier. This embodiment also includes obtaining, from a group membership table, a bit mask corresponding to the multicast group identifier. The bit mask comprises a plurality of bit positions, and each bit position corresponds to a respective egress node of the network. The embodiment also includes encapsulating the data packet with the bit mask and forwarding the encapsulated data packet using the bit mask.

Abstract: Various systems and methods for performing fast fail-over. For example, one method involves electing a first node as a designated forwarder node and electing a second node as a backup designated forwarder node, where the designated forwarder node is used to forward at least a first packet to a downstream node. The method further involves detecting a loss of connectivity between the designated forwarder node and a downstream receiver node, where the designated forwarder node and the backup designated forwarder node are both elected prior to the loss of connectivity occurring. Moreover, subsequent to detecting the loss of connectivity, the method uses the backup designated forwarder node to forward at least a second packet to the downstream receiver node.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: In one embodiment, a device in a network sends a first multicast message to a plurality of destinations in the network. The first multicast message includes a first bitmap that identifies the destinations. The device receives one or more acknowledgements from a subset of the destinations. The device determines a retransmission bitmap that identifies those of the plurality of destinations that did not acknowledge the first multicast message, based on the received one or more acknowledgements. The device sends a retransmission multicast message to those of the plurality of destinations that did not acknowledge the first multicast message. The retransmission multicast message includes the retransmission bitmap.