873 results about "Multicast packets" patented technology

Multicast routing in ad-hoc networks by exchange of multicast group update information and routing tree information among neighboring routers is disclosed. A router propagates multicast group update information based on the update information and the routing tree information. A router also determines whether to forward multicast data packets based on control information in the multicast data packets and the routing tree information.

A network virtualization layer for an information handling system in which a physical machine coupled to a network is divided into a plurality of logical partitions, each of which has a host system residing thereon. In response to receiving a set command from one of the host systems specifying a data link layer (layer 2) address, the virtualization layer associates the data link layer address with the host system and forwards to the host system data packets specifying the data link layer address as a destination address. Unicast packets are forwarded to the single host system specifying the destination address as an individual MAC address, while multicast packets are forwarded to each host system specifying the destination address as a group MAC address. A host system may also specify a virtual LAN (VLAN) ID, which is used to scope the forwarding of packets to host systems sharing that VLAN ID.

An architecture for a line card in a network routing device is provided. The line card architecture provides a bi-directional interface between the routing device and a network, both receiving packets from the network and transmitting the packets to the network through one or more connecting ports. In both the receive and transmit path, packets processing and routing in a multi-stage, parallel pipeline that can operate on several packets at the same time to determine each packet's routing destination is provided. Once a routing destination determination is made, the line card architecture provides for each received packet to be modified to contain new routing information and additional header data to facilitate packet transmission through the switching fabric. The line card architecture further provides for the use of bandwidth management techniques in order to buffer and enqueue each packet for transmission through the switching fabric to a corresponding destination port. The transmit path of the line card architecture further incorporates additional features for treatment and replication of multicast packets.

Techniques for delivering and receiving multicast content across a unicast network are described. A system that supports delivery and reception of multicast content across a unicast network includes a first device and a second device. The first device may be a destination device or a multicast-enabled router. The second device is multicast-enabled, and may be a multicast-enabled router. The first device determines whether a route between a destination device and a source of multicast packets is multicast-enabled, sends a unicast request message that includes as a destination address an address associated with the source and is marked for interception by a second device based on the determination, and receives the multicast packets as unicast packets from the second device. The second device intercepts the unicast request message and delivers the multicast packets to the requesting device as unicast packets in response to the unicast request message. The unicast request message indicates the address of the source and a group address, i.e., a source/group address pair, associated with the multicast packets that the first device wishes to receive.

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. The standard unicast forwarding tables are then consulted to determine the next packet destination addresses, and the router then rewrites the SGM packet and routes it to the next hop router. The routing tables also instruct the router as to which outbound port to route the packet.

A virtual network device sub-unit includes an interface to a virtual network device link and a distributed forwarding module. The interface receives a packet, and the distributed forwarding module forwards the packet received by the interface. The distributed forwarding module performs an ingress lookup if the packet includes a multicast destination address and an egress lookup if the packet includes a unicast destination address. If the packet includes a multicast destination address, the distributed forwarding module replicates the packet for each of several outgoing VLANs associated with the multicast destination address. If an additional multicast packet is received via an interface that is not coupled to a virtual network device link, the distributed forwarding module sends at most one copy of the additional multicast packet via the virtual network device link.

A network switch for network communications is disclosed. The switch includes a first data port interface, supporting at least one data port transmitting and receiving data at a first data rate and a second data port interface supporting a at least one data port transmitting and receiving data at a second data rate. The switch also has a CPU interface configured to communicate with a CPU and a memory management unit for communicating data from at least one of the first and second data port interfaces and a memory. It also has a communication channel for communicating data and messaging information between the first and second data port interfaces and the memory management unit and a plurality of semiconductor-implemented lookup tables including an address resolution lookup table, a layer three IP lookup table and VLAN tables. One of the first and second data port interfaces is configured to determine whether an incoming data packet is a unicast packet, a multicast packet or an IP multicast packet; and the address resolution lookup and layer three IP lookup tables are searched to find an egress port for the incoming data packet.

A method and system for controlling admission of an end user to a multicast channel over a network implementing a source filtering protocol. Incoming packet traffic received by an edge router is snooped and, when a request to join a multicast channel is received, the traffic is analyzed. Any service policy associated with the traffic class is found and applied to packet traffic from the requesting user. The actions include accepting membership in a group associated with a multicast channel and pushing the packets to the end user. If the action is to deny membership, then the multicast packets are prevented from reaching the end user. In addition information is logged and may be used for billing purposes or for accumulating marketing or other such information. Also, the actions may be to limit the number of routing states, by denying admittance to a groups once a limit number of requests to join, or other such parameter, is reached. Such limiting will substantially prevent DOS attacks on a multicast router.

Systems and techniques for supporting multiple multicast trees are described. Some embodiments provide a system that determines an internal multicast group identifier based on a source address, a multicast address, and a multicast tree identifier field associated with a multicast packet. The system can then forward the multicast packet based on the internal multicast group identifier. Specifically, the system can determine a first set of bits based on the source address and the multicast address of the multicast packet. The system can determine a second set of bits based on the multicast tree identifier field of the multicast packet. Next, the system can combine the first set of bits and the second set of bits to obtain the internal multicast group identifier. In some embodiments, the scope of an internal virtual network identifier does not extend beyond a switch or a forwarding module within a switch.

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.

In a wireless network system having a wired backbone network with two or more sub-networks, each having one or more access points for communicating with wireless units via a wireless transmission medium, a system, apparatus and method for a wireless unit to determine whether a candidate access point is on a different sub-network than its current access point. If the wireless unit determines that the candidate access point is on a different sub-network, then the wireless unit releases its current network protocol address which was valid for the current sub-network, and obtains a new network protocol address valid for the new sub-network. This is accomplished by the candidate access point transmitting a multicast packet that includes the network protocol address of the access point and the subnet mask of the sub-network which the access point is on. By receiving this multicast packet, the wireless unit can determine if the candidate access point is on a different sub-network than its current sub-network. Also disclosed is a technique for a wireless unit to determine whether to roam to a candidate access point based on the signal qualities to its current and candidate access points, and whether the candidate access point is on a different sub-network or a designated restricted sub-network.

A system, device, and method for controlling access in a multicast communication network uses a centralized host authentication scheme to prevent unauthorized hosts from joining a shared multicast distribution tree. Each authorized host is allocated a unique authentication key, which is used by the designated router to encode the PIM join message and by the rendezvous point router to authenticate the PIM join message. If the PIM join message is authentic, then each PIM router from the rendezvous point router to the designated router establishes appropriate multicast routes to route multicast packets to the host. If the PIM join message is not authentic, then multicast packets are prevented from reaching the host.

Permitting a mobile host to roam in a foreign network, with multiple access node handoffs, while permitting foreign network multicasting by (i) having the mobile node (MN) use a persistent address, for purposes of multicasting, and (ii) relaxing or modifying reverse path forwarding checks, and (iii) modifying the forwarding of multicast packets sent from a non-local source address. The persistent address, used in mobile networks as the source address in the IGMP Membership reports and the multicast packets, may be the permanent and hence stable host home address (HoA). This enables the HoA to be supported as a source address by foreign agents (FAs) and multicast routing protocols in foreign networks.

A multicast packet readout control method is disclosed. An input multicast packet is temporarily stored in a multicast queue of a packet buffer. The multicast packet is read from the multicast queue, and converted into a unicast packet addressed to each of the destinations of the multicast packet. The converted unicast packet is stored in a unicast queue of the packet buffer. The converted unicast packet is then read from the unicast queue and transmitted to the destination.

A method and apparatus for a router to inform a Layer 2 switch by use of packets of a new router group port management protocol (RGMP) that the layer 2 switch is to forward multicast packets of a specified group to the router. First the router transmits a RGMP HELLO packet to the layer 2 switch to inform the switch that the router is a multicast router implementing the invention. Then, in the event that the router receives an IGMP packet from an end station requesting multicast packets of a particular group, in response the router sends an RGMP JOIN packet to the layer 2 switch. The RGMP JOIN packet requests that the layer 2 switch forward only multicast group packets, of the group whose group number is written into a field of the RGMP JOIN packet, to the router. Also, the router sends a prior art PIM JOIN packet to other multicast routers in order to be placed on the multicast distribution tree for that group. The layer 2 switch builds a forwarding table for multicast groups listing ports connected to routers having sent a RGMP JOIN for that group. When a multicast group packet arrives at the layer 2 switch, the switch uses the forwarding table to forward the packet only to those routers requesting that group.

An architecture for a line card in a network routing device is provided. The line card architecture provides a bi-directional interface between the routing device and a network, both receiving packets from the network and transmitting the packets to the network through one or more connecting ports. In both the receive and transmit path, packets processing and routing in a multi-stage, parallel pipeline that can operate on several packets at the same time to determine each packet's routing destination is provided. Once a routing destination determination is made, the line card architecture provides for each received packet to be modified to contain new routing information and additional header data to facilitate packet transmission through the switching fabric. The line card architecture further provides for the use of bandwidth management techniques in order to buffer and enqueue each packet for transmission through the switching fabric to a corresponding destination port. The transmit path of the line card architecture further incorporates additional features for treatment and replication of multicast packets.

A method is described for receiving a multicast in user devices in a network issuing a request to join a multicast group, identifying multicast data packets associated with the multicast group, monitoring transmissions of the multicast data packets to determine whether the identified multicast data packets are being transmitted in an already established unicast session and establishing a unicast session and processing multicast data packets if an already established unicast session does not exist A method is described for receiving a multicast transmission in user devices in a network establishing a unicast session with a dedicated terminal, identifying multicast data packets associated with a multicast group, monitoring transmissions of the multicast data packets and processing the multicast data packets by the dedicated terminal. Additonally, an apparatus is described for accepting a request to join a multicast group, for identifying multicast data packets associated with the multicast group, establishing a unicast session, for encapsulating said multicast data packets in a unicast frame and for forwarding the unicast frame via the unicast session.

Multicast systems and methods for Segment Routing include receiving, at a node, a multicast packet including an outer label comprising a Multiprotocol Label Switching (MPLS) source node identifier defining a source-rooted broadcast tree and an inner label including a service identifier defining a service specific multicast tree; responsive to the node including a branch point on the source-rooted broadcast tree, popping the outer label, analyzing the inner label to identify active egress ports, pushing back the outer label, and forwarding the multicast packet to the active egress ports; and responsive to the node including point-to-point transit for the source-rooted broadcast tree, forwarding the multicast packet on the source-rooted broadcast tree.

An architecture for a line card in a network routing device is provided. The line card architecture provides a bi-directional interface between the routing device and a network, both receiving packets from the network and transmitting the packets to the network through one or more connecting ports. In both the receive and transmit path, packets processing and routing in a multi-stage, parallel pipeline that can operate on several packets at the same time to determine each packet's routing destination is provided. Once a routing destination determination is made, the line card architecture provides for each received packet to be modified to contain new routing information and additional header data to facilitate packet transmission through the switching fabric. The line card architecture further provides for the use of bandwidth management techniques in order to buffer and enqueue each packet for transmission through the switching fabric to a corresponding destination port. The transmit path of the line card architecture further incorporates additional features for treatment and replication of multicast packets.

Systems and methods for IP multicast packet burst absorption and multithreaded replication architecture are disclosed. Replications of IP multicast packets are performed in a control plane of a network device. The network device may include a data plane for transmitting data between ingress and egress ports and a control plane including a shared transmit/receive queue infrastructure configured to queue incoming multicast packets to be replicated on a per ingress port basis and to queue transmit packets, and a multicast processing engine in communication with the shared queue infrastructure and including a circular replication buffer to facilitate multithreaded replication of multicast packets on a per egress virtual local area network (VLAN) replication basis. The shared transmit/receive queue infrastructure may dynamically allocate memory between the transmit and receive multicast queues.