Abstract: A method and apparatus for fast reroute of multicast data are disclosed. In one embodiment, a method includes transmitting a multicast join message from a receiver towards a source on a primary path and transmitting an alternate multicast join message from the receiver towards the source on a backup path. Data packets are then received from the primary and backup paths. The method further includes operating in a first mode wherein the data packets received from the primary path are accepted and the data packets received from the backup path are dropped, and switching to a second mode wherein the data packets received from the backup path are accepted, upon detecting a failure in the primary path.

Abstract: In one embodiment, an indication of a fault condition is received relating to a first service running on a physical device in a computer network. The first service is associated with a first virtual device context defined on the physical device. Then, the first service is disabled without affecting operation of a second service on the physical device. The second service is associated with a second virtual device context defined on the physical device. In another embodiment, a first virtual device context is created on a physical device in a computer network. Then, a second virtual device context is created on the physical device. The first virtual device context may then be managed independently of the second virtual device context such that resources assigned to a virtual device context are managed without affecting management of another virtual device context.

Abstract: In one embodiment, a solution is provided wherein redundant routers are treated as a single emulated switch. When a packet is received at a layer 2 edge switch from a host, the layer 2 edge switch may determine a switch identifier for the emulated switch using a destination anycast hardware address contained in the packet. The anycast hardware address may identify an emulated switch comprising a plurality of routers. Then a header may be added to the packet, the header including the switch identifier. Following that, the packet may be forwarded to another layer 2 switch along a shortest path from the layer 2 edge switch to the emulated switch.

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: 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: Systems and methods for implementing a bidirectional multicast protocol with two types of join messages are disclosed. The two types of join messages, upstream joins and downstream joins, are used to control the Reverse Path Forwarding (RPF) interface is added to the outgoing interface list for a particular multicast group, which in turn controls when multicast packets will be forwarded to the rendezvous point. One method involves receiving a multicast packet addressed to multicast group G. The method inhibits the multicast packet from being forwarded via the RPF interface, unless the outgoing interface list corresponding to the multicast group G already identifies the RPF interface. The RPF interface can be added to the outgoing interface list in response to reception of a downstream join message via the RPF interface, as well as in response to monitoring, via the RPF interface, an upstream join message on a shared network segment.

Abstract: A provider edge (PE) node of a network operates to send a trace path message over the network to a receiver PE node, the trace path message recording a list of intermediate nodes of a unicast path from the PE node to the receiver PE node; and receive a join message initiated from the receiver PE node, the join message using the list to propagate to the source PE node through the intermediate nodes such that a branch of a multicast tree is aligned with the unicast path. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A mechanism that provides congruent forwarding paths for unicast and multicast data traffic over a service provider core network includes issuing, by a receiver edge node, a request to join a multicast tree structure. A unicast path from the receiver edge node to a source node of the provider network is then established using a special message that contains an identifier. The identifier allows the unicast path through the core network to be aligned with the multicast tree structure. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Various systems and methods are disclosed for performing multicast routing over unidirectional links. For example, one method involves maintaining a multicast adjacency sate, which is associated with an interface that is coupled to receive messages from a network device via a unidirectional link. The multicast adjacency state identifies a network address of the network device. The method also involves sending a multicast protocol control message to the network device via a bidirectional path. The destination address of the network multicast protocol control message is the network address in the multicast adjacency state.

Abstract: Various systems and methods are disclosed for performing multicast routing over unidirectional links. For example, one method involves maintaining a multicast adjacency state, which is associated with an interface that is coupled to receive messages from a network device via a unidirectional link. The multicast adjacency state identifies a network address of the network device. The method also involves sending a multicast protocol control message to the network device via a bidirectional path. The destination address of the network multicast protocol control message is the network address in the multicast adjacency state.

Abstract: A method and system for translation of virtual private network (VPN) addresses over a provider network are disclosed. The method includes creating a multipoint tunnel extending between customer edge routers in a VPN network and over the provider network. The multipoint tunnel is identified with a multicast address and multicast packets are sent over the tunnel to identify tunnel endpoints at customer edge routers within the VPN. The method further includes converting, at one of the customer edge routers, a VPN join message to a provider join message and sending it over the provider network.

Abstract: A data structure is stored in a memory of a router, the router located along a path between a source end station and a plurality of destination end stations in a multicast distribution tree. In response to receipt of trace packets containing a listing of network devices in the multicast distribution tree, the data structure is updated. When the source end station desires to send a multicast packet, it transmits a packet to the router. The router then writes the path information stored in the data structure into the packet. Such path information may include a tree list that specifies the arrangement of network devices along the multicast distribution tree and an address list that specifies the Internet Protocol (IP) addresses of these network devices along the multicast distribution tree. By storing the complete description of the network devices of the multicast distribution tree in the packet, routing demands on the devices along the multicast path are minimized.

Abstract: The invention solves the problem of overloading intermediate routers with state information as the number of multicast groups increases to millions of groups. The invention places multicast delivery tree information in the header of an encapsulated multicast packet, thereby relieving the routers from maintaining any state information about the multicast groups. The encapsulated packet is referred to as a small group multicast packet, or SGM packet. Routers which are neither branch points of the delivery tree nor destination routers will also need to do no additional forwarding processing other than that needed for standard unicast forwarding. A protocol designation field in the Layer 3 header informs the router that the packet is a SGM packet, and that the router is therefore instructed to parse the packet for route information. The router parses the SGM packet header and determines the next hop address of routers in the multicast delivery tree.

Abstract: A test monitoring device for detecting a fault in a multicast routing infrastructure includes a processor, a memory coupled with the processor, and a network interface coupled with the processor. The device is configured to send a source configuration request for configuring a device in the infrastructure to be a test packet source, and a receiver configuration request for configuring one or more devices in the infrastructure to be test packet receivers where the test packet source sends out test packets to a predetermined group of test packet receivers. The source configuration request contains an identifier identifying the test monitoring device. The predetermined group has a group identifier. The device is also configured to examine data reports from the test packet receivers relating to a plurality of test packets sent by the test packet source.

Abstract: The invention provides a method and system for multicast packet routing, in which only selected routers in a network subset (in a preferred embodiment, those routers on the border of the domain) maintain routing information external to the network subset, while all other routers in the network subset (non-border routers) maintain only information regarding routing within the network subset, including which border routers are on the path from the multicast source device or to the destination devices. The network subset is preferably a domain or other routing domain. A multicast distribution tree is maintained, using protocol messages which are transmitted from leaf nodes toward a root of the tree, while data packets to be multicast are distributed from the root toward the leaf nodes. In each network subset, such as a routing domain, each multicast packet is associated with a multicast distribution tree.

Abstract: A method and system for detecting faults in data packet routing devices in a computer network capable of routing messages using a multicast protocol is described. Faults in devices, such as routers and switches, are detected in near real-time when using a multicast routing infrastructure by configuring a device to be a sender or source of test data packets and one or more other devices to receive test data packets. The test packet sender transmits test data packets to a test group of test packet receivers where the test group has a group identifier. The test receivers prepare data or fault reports describing errors regarding missing or duplicated data packets. These fault reports are prepared soon after the errors are detected and sent back to a multicast routing manager for isolating the device causing the fault. The messages sent to the test devices contain instructions regarding time intervals during which fault reports can be sent to the multicast routing manager from the multiple test receivers.

Abstract: The invention provides a method and system for content-based filtering of multicast information. A set of sources (S) which desire to distribute potentially large numbers of categories of differing information each associates a content descriptor (CD) with messages including information in those categories, so that a set of recipients (R) can receive information in at least some of those categories. A mapping server (M) associates a multicast address (MA) and a content mask (CM) with each content descriptor, so that network elements (N), such as routers, in the network can distribute only those messages which are of interest to recipients in multicast distribution trees for those multicast addresses. Each source generates content descriptors for each differentiable topic in a tree structured hierarchy, and obtains a multicast address and a content mask for the broadest content descriptor it is capable of distributing.

Abstract: The invention provides a method and system for multicast group routing using unidirectional links. A set of uplink routers and a set of downlink routers provide a primary unidirectional distribution path from a set of sources to a set of destinations. A relatively smaller reverse communication channel is provided between the destinations and the sources. When a destination desires to add itself to, or take itself off, a multicast distribution group, one of the downlink routers acts as a proxy for that destination and so informs the relevant source. The selection of the proxy reporter for downlink routers or the querier for uplink routers does not require bi-directional communication between either of them, respectively.

Abstract: The invention provides a method and system for multicast packet routing, in which only selected routers in a network subset (in a preferred embodiment, those routers on the border of the domain) maintain routing information external to the network subset, while all other routers in the network subset (non-border routers) maintain only information regarding routing within the network subset, including which border routers are on the path from the multicast source device or to the destination devices. The network subset is preferably a domain or other routing domain. A multicast distribution tree is maintained, using protocol messages which are transmitted from leaf nodes toward a root of the tree, while data packets to be multicast are distributed from the root toward the leaf nodes. In each network subset, such as a routing domain, each multicast packet is associated with a multicast distribution tree.

Abstract: The invention provides a method and system for content-based filtering of multicast information. A set of sources (S) which desire to distribute potentially large numbers of categories of differing information each associates a content descriptor (CD) with messages including information in those categories, so that a set of recipients (R) can receive information in at least some of those categories. A mapping server (M) associates a multicast address (MA) and a content mask (CM) with each content descriptor, so that network elements (N), such as routers, in the network can distribute only those messages which are of interest to recipients in multicast distribution trees for those multicast addresses. Each source generates content descriptors for each differentiable topic in a tree structured hierarchy, and obtains a multicast address and a content mask for the broadest content descriptor it is capable of distributing.