972 results about "Multicast message" patented technology

The present invention is a system, method and network (110) for multicast distribution of presence information to a plurality of communication devices (102, 104, 106, 108). A contact list (122, 124, 126, 128), associated with each communication device, identifies one or more of the other communication devices. The network provides one or more multicast addresses based on the contact lists of the communication devices to the plurality of communication devices. The network also sends multicast messages identified by the one or more multicast addresses to the plurality of communication devices. Each multicast address identifies a group of multicast devices among the plurality of communication devices, and the multicast messages include presence information about the group of multicast devices. A portion of the plurality of communication devices receives the multicast messages identified by the one or more multicast addresses and extracts the presence information about the group of multicast devices from the multicast messages.

A method and communication device for routing unicast and multicast messages. The method for routing a unicast message includes receiving a first control packet including routing parameters from a group header node, updating a routing table based upon the routing parameters, receiving a second control packet including additional routing parameters from a group node, updating the routing table based upon the additional routing parameters and generating a forwarding table from the routing table when both of the updated steps are completed. The unicast message is routed based upon the forwarding table. A method for routing a multicast message comprises receiving the multicast message, determining if a multicast group destination for the multicast message is in a multicast forwarding table (MFT), determining if the multicast message has been previously forwarded and forwarding the multicast message if the message was not previously forwarded and the multicast group destination is in the MFT.

A method and apparatus for providing multicast messages across a data communication network, the method comprising the computer-implemented steps of: receiving a multicast join message; adding to the multicast join message a next hop and an address of a router to which the multicast message is to be sent; forwarding the multicast message based on the next hop address.

Systems and methods are provided for managing and delivering status notifications relating to multicast messages transmitted from a sending communication device to multiple recipient communication devices. Each communication device is provided with a status agent for detecting transmission of messages to a recipient device and receipt of messages from a sending device. Upon transmission, the status agent notifies a status service of the outbound message. Upon receipt of the multicast message by one of the recipients or upon the message being marked read, the recipient status agent notifies the status service. The status service then notifies the status agent of the sending device that the message has been received or read by that recipient, so that the sending device's status agent can notify a corresponding messaging application. The status service operates to reconcile outbound message notifications and received or read status updates for multicast messages.

A method performed by a first computer node for selecting a leader node to provide service to a plurality of other nodes in a multicast group, wherein each of the nodes communicates using multicast messages, comprises issuing a first election call message; receiving candidacy announcement messages from one or more leader candidate nodes in a specified time period; selecting a victor from among all leader candidate nodes from which candidacy announcement messages are received; receiving one or more victor announcement messages from one or more leader victor nodes for a second specified time period; resolving zero or more collisions among the victor announcement messages to result in selecting the leader node. One embodiment provides a dynamic secure protocol for electing a key server, such as a key server that is suited for use with a group key exchange protocol such as the Group Domain of Interpretation (GDOI). Public key signatures may be used to secure message exchanges and to provide for authentication of network nodes in a multicast group.

Protocols for messaging between a centralized network management system and other entities are described. According to one embodiment, in response to a request of a subscriber for joining a multicast group received at a centralized aggregation server, the centralized aggregation server transmits a port subscriber announcement (PSA) message to substantially all subscriber access multiplexers over an access network. The PSA message includes an identifier (ID) of the subscriber. In response to the PSA message, a subscriber access multiplexer having a subscriber matching the ID of the subscriber in the PSA message identifies a user port corresponding to the subscriber and applies a local service policy to the identified user port. Subsequent multicast messages destined to the subscriber are delivered by the subscriber access multiplexer to the subscriber based on the local service policy corresponding to the receiving subscriber without having the aggregation server handling the service policy of the receiving subscriber. Other methods and apparatuses are also described.

An information relay device connected between a plurality of logical or physical networks for performing an operation for relay of information between the networks is provided with a transmit / receive processing unit for receiving a general purpose multicast message from one of the plurality of networks and transmitting a multicast message to at least one of the plurality of networks, and a protocol conversion processing unit for converting, in the case where the general purpose multicast message received by the transmit / receive processing unit is a multicast protocol message of a certain level layer, the multicast protocol message of the certain level layer into a multicast protocol message of another level layer.

A communication system in which multiple protocols and proxy services are executed by an access point. In one embodiment of the invention, GVRP and GMRP registrations are combined in a single packet when a wireless device roams to a different VLAN. In addition, outbound GVRP and GMRP multicast messages are handled by an access point (also referred to as a GVRP and GMRP “gateway”) such that the wireless device is not burdened with the associated computational overhead. In a further embodiment, a wireless device may dynamically switch between a VLAN-aware state and a VLAN-unaware state depending on the nature of a detected access point. For example, if a relevant access point supports GVRP, the wireless device may operate as a VLAN terminal. If a wireless device is not attached to an access point with a matching VLAN ID, the wireless device sends and receives VLAN tagged frames. If a wireless device configured with a VLAN ID is attached to an access point with a matching VLAN ID, or if the wireless device is attached to a non-VLAN access point, then the wireless device may send and receive raw / untagged frames. In addition to the gateways described below, the ability of a wireless device to detect when it can send untagged frames is considered novel. In another embodiment of the invention, a special ID that is different than the native VLAN ID for a switch port is used for VLAN-unaware devices. This allows such devices that do not issue tagged frames to belong to a single VLAN ID.

One embodiment of the present invention provides a system that facilitates bandwidth-efficient multicast in EPONs. The system includes a central node and at least one remote node. Downstream data from the central node is broadcast through a passive optical coupler to remote nodes. In the other direction, upstream data from a remote node is transmitted through the passive optical coupler to the central node in a unicast manner. During operation, the system first selects a common multicast LLID to represent a number of remote nodes that comprise a multicast group. Upon receiving a multicast message destined to the multicast group, the system sends the multicast message along with the multicast LLID for the multicast group, whereby the multicast message is broadcast through the passive optical coupler in the downstream direction. This allows each remote node belonging to the multicast group to receive the multicast message by matching the multicast LLID.

A method and system to acknowledge a multicast message includes informing each node in a network about each multicast group to which it belongs, a relative position in each multicast group to which it belongs, and a group size of each multicast group to which it belongs, transmitting the multicast message, and transmitting, by each node in the multicast group, an acknowledgment in an assigned slot, which is determined by the relative position.

A method to organize nodes into an overlay network and to disseminate multicast messages within this overlay both through an efficient tree embedded in the overlay and through gossips exchanged between overlay neighbors. Regardless of the size of the system, this invention incurs a constant low overhead on each node.

A method that rapidly reconfigures a computer network having a plurality of devices executing the spanning tree algorithm. First, one or more devices are configured and arranged so that one port, providing connectivity to the root, is in the forwarding state and the remaining ports, providing connectivity to the root, are in the blocked state. Next, one or more of the blocked ports are designated as back-up ports. Upon detection of a failure at the active forwarding port, one of the back-up ports immediately transitions from blocked to forwarding, thereby becoming the new active port for the device. Following the transition to a new active port, dummy multicast messages are transmitted, each containing the source address of an entity directly coupled to the affected device or downstream thereof. By examining the dummy multicast messages, other devices in the network learn to use to the new forwarding port of the affected device. Rapid reconfiguration of the network is also provided upon detection of a new or repaired link or device representing a better path toward the root. The method is also compatible with networks supporting virtual local area network (VLAN) designations and allows load balancing among different VLANs.