Abstract: A method, system and an apparatus to transport bidir PIM over a multiprotocol label switched network is provided. The method may comprise receiving a multicast packet at a network element, the multicast packet including an upstream label. The method may further comprise identifying, from the upstream label, a Multicast Distribution Tree (MDT) rooted a rendezvous point. The packet may be forwarded along the MDT towards the RP based on the upstream label. The MDT may be identified from a downstream label and the packet may be forwarded the along the MDT away from the RP based on the downstream label.

Abstract: An apparatus or method for upstream label allocation on LANs for multipoint (MP) label switched paths (LSPs). In one embodiment of the method, a first router receives a first incoming labeled data packet, wherein the first incoming labeled data packet comprises a first data packet and one or more first labels. The first router creates a first outgoing labeled data packet, wherein creating the first outgoing labeled data packet includes the step of swapping the one or more first labels of the first incoming labeled data packet with a context label and a forwarding label, wherein the first outgoing labeled data packet comprises the first data packet, the context label, and the forwarding label. Ultimately, the first router transmits the first outgoing labeled data packet to second and third routers via a LAN.

Abstract: A method, apparatus, or computer executable instructions for converting Protocol Independent Mode (PIM) requests. In one embodiment, the method includes receiving a first multicast routing protocol (MRP) message, wherein the first MRP message is a request to join a multicast group of receivers. The first MRP message is translated into a second MRP message, wherein the second MRP message is a request to join the multicast group of receivers to which data is being provided by a specific source. The method could be performed by a router contained in a sparse mode network, wherein the sparse mode network is coupled to a source specific mode network that contains the specific source.

Abstract: A method of routing multicast traffic in a computer network is disclosed. The method comprises associating a plurality of multicast group addresses on a network device with respective multicast routing topologies. A network device and a network are also disclosed.

Abstract: Techniques reliably provide the switchover from a default MDT to the data MDT by using reliable signaling and reliable building of a data MDT. The message notifying of the pending switchover to the data MDT is reliably sent using signaling that is reliable. Also, the switchover from the default MDT to the data MDT does not happen until all egress routers have responded to the message. Egress routers join the data MDT if associated receivers are interested in receiving the multicast stream from a source. The router does not send another response upstream until all egress routers downstream from it respond to the message in the positive or the negative.

Abstract: Techniques for dynamically distribute replication points based on routing metrics are provided. A receiver list may be split based on the routing metrics. For example, the receiver list may be split based on unicast reachability over an interface. If portions of egress routers are reachable over different interfaces, the portions are included together in a sublist. Thus, the list is split into sublists based on the reachability. Point-to-point links are then set up between a head end router and an egress router in each sublist. The sublist is then sent to each egress router, which can perform the process above in setting up a point-to-point link to another egress router in each sublist.

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 method of using a point-to-point (P2P) label switched path (LSP) to transmit multicast data packets partially through a multiprotocol label switched (MPLS) network when one or more label switched routers (LSRs) of the MPLS are not multicast label distribution protocol (mLDP) enabled. The P2P LSP can be used to transmit multicast data packets to the head end of a point-to-multipoint (P2MP) LSP created with mLDP enabled LSRs. The P2MP LSP can be used to transmit the multicast data packets through the MPLS network to intended receivers that are external to the MPLS network. When configuring the P2MP LSP, an mLDP enabled LSR receives a first message from a non-mLDP enabled MPLS core router in response to sending a label mapping message to the non-mLDP enabled MPLS core router. In response, a directed LDP session is created between the mLDP enabled LSR and an edge LSR in one embodiment in response to receiving the first message from an MPLS enabled core router.

Abstract: Various systems and method for rerouting multicast traffic in response to detecting imminent network disruption are disclosed. One method involves detecting an imminent topology change and, in response, identifying a new multicast distribution tree for a multicast group. A join message for the multicast group is then sent towards a root of the new multicast distribution tree. Multicast traffic addressed to the multicast group continues to be forwarded via the current multicast distribution tree, subsequent to sending the join message. The multicast traffic is not forwarded via the new multicast distribution tree until one or more multicast data packets have been received via the new multicast distribution tree.

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 by which PIM network traffic can be aggregated is provided, thereby reducing the number of PIM messages transmitted by routers in a multicast network. PIM messages are adapted to permit information targeted at multiple destination routers to be included in one PIM message. Join/prune lists for a plurality of upstream neighbor routers can thereby be included in a single PIM message. PIM Hello messages can be similarly aggregated in a single PIM message and both PIM join/prunes and PIM Hellos can be aggregated in a single aggregated PIM message. Through such aggregation of information that would traditionally be transmitted in multiple PIM messages, network bandwidth consumption and router load due to transmission of PIM messages can be reduced.

Abstract: Various techniques for exchanging control messages in order to gracefully reroute multicast traffic are disclosed. For example, one method involves sending a join message for a multicast group towards a root of a new multicast tree and forwarding multicast traffic, addressed to the multicast group, on a current multicast tree until an acknowledgment corresponding to the join message is received. The new multicast tree can be identified in response to detection of a topology change within the network. Until the acknowledgment is received, multicast traffic that,is received via the new multicast tree can be dropped.

Abstract: A mechanism is provided by which a transport tree identifier can be generated using one or more identifiers for a multicast datastream. The transport tree identifier can then be used in the process of building a transport tree across a transport network. A transport network egress router can receive a request to join a multicast datastream from a downstream node outside of the transport network. The information contained in the join message that identifies the desired multicast datastream can be encoded in the transport tree identifier. The transport tree identifier can be related to one or more of a multicast group destination address, a multicast datastream source address, and a broadcast domain identifier.

Abstract: A Multicast Source Discovery Protocol (MSDP) speaker can associate a “key” with a set of one or more source address/group address pairs within a Source Active (SA) message and send the SA message to a MSDP peer. Initially, the MSDP speaker sends both the key and the source address/group address pairs associated with that key. Subsequently, the MSDP speaker can simply resend the key, without also sending all of the associated source address/group address pairs, in order to refresh the SA information at the peer. Additionally, several keys can be sent in a single message.

Abstract: A mechanism to dynamically map a multicast session to a transport tree to reduce flooding of egress routers on the transport tree is provided. A mechanism to reduce the length of time in which transient flooding can occur while the transport tree is being chosen or configured is also provided. The disclosed dynamic mapping mechanisms avoid interruption of an established multicast session. One mechanism disclosed provides for remapping of a multicast session by cloning an original transport tree with which the multicast session is associated, associating the multicast session with the cloned transport tree, and then reconfiguring the cloned transport tree in accord with edge egress routers that have subscribers to that multicast session.

Abstract: Each of several routers connected to a LAN elects the same router as the designated router for a multicast group identified by a multicast address. Each of the several routers implements a method for electing the designated router. The method includes in one embodiment, generating several values corresponding to the several routers, respectively. The several values are generated as a function of the several routers' IP addresses, respectively, and an IP address of a first multicast group. The values, in one embodiment, are then compared to determine which is the largest. Thereafter each router elects as the designated router for the multicast group, the router corresponding to the largest value.

Abstract: An apparatus and method for emulating a shared or source distribution tree within an MPLS network. In one embodiment of the method, a router receives a multicast data packet. The router transmits the multicast data packet to a first router via a first point-to-point label switched path (LSP). The router replicates the multicast data packet to produce a replicated multicast data packet. Then the router transmits the replicated multicast data packet to a second router via a second point-to-point LSP. The first point-to-point LSP is distinct from the second point-to-point LSP.

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: In the disclosed active multicast information protocol, a first edge router of a network receives a data packet from a source, wherein the data packet comprises data to be sent to receivers of a multicast group. The first edge router may rout the data packet to a first core router within the network. The first edge router also generates a message in response to receiving the data packet. This message is transmitted to the first core router within a network. The message includes an address of the source, but the message lacks data to be transmitted to the receivers of the multicast group. Another edge router stores the first multicast group and source addresses in an entry of a look-up table (LUT) in response to the edge router receiving a first message directly or indirectly from the first edge router.

Abstract: In the disclosed active multicast information protocol, a first edge router of a network receives a data packet from a source, wherein the data packet comprises data to be sent to receivers of a multicast group. The first edge router may rout the data packet to a first core router within the network. The first edge router also generates a message in response to receiving the data packet. This message is transmitted to the first core router within a network. The message includes an address of the source, but the message lacks data to be transmitted to the receivers of the multicast group. Another edge router stores the first multicast group and source addresses in an entry of a look-up table (LUT) in response to the edge router receiving a first message directly or indirectly from the first edge router.