Abstract: A method for converging on a route through a radio frequency (RF) communications network, that includes multiple nodes, includes (a) identifying all RF links between each node in the RF communications network; (b) determining a connectivity confidence interval for each RF link by: (aa) developing a calculated signal to noise ratio using a radio frequency communication link propagation loss model; (bb) determining a threshold signal to noise ratio based on a predetermined RF packet completion rate; (cc) determining a standard deviation value based on a signal strength and a noise level at a signal receiving node; (dd) calculating a Z number, associated with a normal distribution table which is based on the threshold signal to noise ratio minus the calculated signal to noise ratio with that result being divided by the standard deviation value; and (ee) assigning a CCI probability value based on said Z number.

Abstract: Multiple comparators compare the enable and priority values for multiple inputs and select a winner from one of the inputs. Multiple comparator stages each include one or more of the comparators. Each comparator stage selects winners from the outputs of a preceding comparator stage. The overall winners are those inputs that are winners in each comparator stage. If there are multiple overall winners, a second arbitration is preformed to identify an ultimate winner.

Abstract: A method for forming channelized groups in a wireless communication network having a plurality of nodes. At least one node in the network is assigned to a first channel that is associated with a channelized group having a first set of nodes. The method determines whether there is contention between the at least one node and the first set of nodes. In addition, the method includes switching the at least one node from the first channel to a second channel based on the contention determination.

Abstract: A system, device, and method for receiver access control in a multicast communication network uses a policy service to determine whether a subscriber device can be admitted to a multicast group. The subscriber device accesses the multicast communication network via an access device. The access device uses a policy service to obtain a policy decision from a policy server, where the policy decision indicates whether or not the subscriber device can be admitted to the multicast group. The access device enforces the policy decision by admitting the subscriber device to the multicast group if and only if the policy decision indicates that the subscriber device can be admitted to the multicast group.

Abstract: Principles of the invention are described for providing multicast virtual private networks (MVPNs) across a public network that are capable of carrying high-bandwidth multicast traffic with increased scalability. In particular, the MVPNs may transport layer three (L3) multicast traffic, such as Internet Protocol (IP) packets, between remote sites via the public network. The principles described herein may reduce the overhead of protocol independent multicast (PIM) neighbor adjacencies and customer control information maintained for MVPNs. The principles may also reduce the state and the overhead of maintaining the state in the network by removing the need to maintain at least one dedicated multicast tree per each MVPN.

Abstract: Principles of the invention are described for providing virtual private local area network service (VPLS) multicast instances across a public network by utilizing multicast trees. In particular, the VPLS multicast instances transport layer two (L2) multicast traffic, such as Ethernet packets, between customer networks via the public network. The principles described herein enable VPLS multicast instances to handle high bandwidth multicast traffic. The principles also reduce the state and the overhead of maintaining the state in the network by removing the need to perform snooping between routers within the network.

Abstract: A technique controls distribution of reachability information for a tail-end node of a traffic engineering (TE) label switched path (LSP) to a head-end node of the TE-LSP in a computer network. The TE-LSP preferably spans multiple domains of the network such that the tail-end node resides in a domain (“tail-end domain”) that is different (remote) from the domain of the head-end node (“head-end domain”). According to the inter-domain information distribution technique, the head-end node requests the remote reachability information from the tail-end node, which may employ an Interior Gateway Protocol (IGP) to transmit the information to a border router of the tail-end domain. The tail-end domain border router then shares this information with at least a head-end domain border router. The head-end node thereafter requests that the head-end domain border router release the reachability information into the head-end domain. The head-end node uses the remote information to calculate routes, i.e.

Abstract: Stored in the leaf nodes of a data structure that can be used for identifying the longest prefix matching an address are corresponding values from multiple forwarding information bases. A single common address lookup data structure (e.g., a tree, trie, etc.) can be used, and a leaf node can contain information from multiple forwarding information bases. If lookup operations are performed for a single address in multiple forwarding information bases, the single common address lookup data structure may only need to be traversed once. For example, the forwarding information for another forwarding information base may be stored in the same leaf, further down in the data structure requiring traversal from the current position, or above requiring traversal from the root of the lookup data structure. Information can be stored in the leaf node to indicate which traversal option is appropriate for a particular forwarding information base.

Abstract: A communication network system includes: a plurality of lower hierarchy networks, each having a plurality of first relay apparatuses; and an intermediate hierarchy network having a plurality of second relay apparatuses for connecting the plurality of lower hierarchy networks via the second relay apparatuses at the edge position line-connected to the first relay apparatuses at the edge position. Each of the first relay apparatuses has a first routing table that holds information limited to routing information corresponding to the first relay apparatus and routing information on at least one of the first relay apparatuses and the second relay apparatuses in the edge positions that come into an adjacent state. Each of the second relay apparatuses has a second routing table that holds information including routing information on at least one of the second relay apparatuses and the first relay apparatuses in the edge positions that come into an adjacent state.

Abstract: A synchronous optical network (SONET) system having multi-hierarchal network service access point (NSAP) addressing includes electrically linked network elements (NEs) and first and second level routing areas which each include at least one NE. The NEs include devices having respective NSAP addresses and at least one of the NEs is a network controller that controls the SONET. The first level routing area and the second level routing areas are based on a predetermined prioritization of the NEs as first level NEs and second level NEs, and have a first level routing and having a second level routing for the NSAP addresses, respectively. Each NSAP address includes a Routing Domain field and an Area field filled with information indicative of a respective Internet Protocol (IP) address.

Abstract: A method for utilizing a Spanning Tree Protocol (STP) in an Ethernet network wherein a number of VLANs are defined and a plurality of Ethernet switching nodes (A, B, C D E, F,G H) are interconnected via their ports (A1, . . . ,H4) so that each of the ports is initially assigned to one or more VLANs, and each of the VLANs is intended to enable traffic between two or more edge ports (D3, B3). The method comprises a so-called pruning procedure initiated upon establishing a new STP topology (30) related to one or more VLANs. This procedure concerns a broadcast domain of at least one of the VLANs and is aimed at obtaining a sub-tree for each pruned VLAN in the new STP topology. The sub-tree is usually shrunk, bound by the edge ports assigned to the corresponding pruned VLAN, and thus eliminates broadcast traffic of the pruned VLAN to any Ethernet switch extending beyond the obtained sub-tree.

Abstract: Provided is a routing method capable of expanding a conventional tree routing to perform the efficient and safe key management in a sensor network environment that requires the symmetric key based key management. Each sensor node transmits a Route Reverse message to a sink node to set a reverse tree routing path. Therefore, it is possible to provide efficient and safe key management mechanism and communication environment by providing a bidirectional communication between a sink node and sensor nodes through an expanded tree routing such that a user is provided with a safe sensor network.

Abstract: A method of managing a computer network switch is disclosed. The method has the steps of: setting a port of the switch to root guard protected status (RG status); selecting by a spanning tree protocol (STP) the port as a designated port; and setting said port into blocked status, in response to said port being both in root guard protected status and selected by STP as a root port. By setting a port to root guard protected, the port is prevented from becoming a designated port, and so then forcing the root port to remain in a desired core network.

Abstract: The invention is a system for distributing content data over a computer network and a method of arranging receiver nodes in a computer network such that the capacity of the server is effectively multiplied many times over, and may even be increased exponentially. The invention takes advantage of the excess capacity many receiver nodes possess, and uses them as repeaters. The distribution system includes nodes having databases which indicate their ancestors and descendants so that reconfiguration of the distribution network may be accomplished without burdening the systems primary server. The invention includes a process for configuring a computer information distribution network having a primary server node and user nodes docked in a cascaded relationship, and reconfiguring the network in the event that a user node departs from it.

Abstract: A method and apparatus are provided for routing a packet within a plurality of n nodes arranged in a line or tree (or a combination of the foregoing), given a maximum stack depth, s. A fixed stack process for routing packets on a line given a stack depth, s, initially divides a line of n nodes into segments, such as n1/s approximately equal segments. A unique label is assigned to each segment and, within each segment, one of up to n1/s labels is assigned to each node. A fixed stack process for routing packets on a tree, given a target stack depth, s, initially identifies a subset, S, of at nodes from the tree, such as at most 3 n1/s nodes, such that after the subset, S, is removed, each remaining subtree has at most n(s-1)/s nodes. A unique label is assigned to each of the nodes in the subset S and, within each remaining subtree, one of up to n(s-1)/s labels is assigned to each node.

Abstract: A method for selecting a neighboring node to synchronize network topology database information with a network node from among a plurality of neighboring nodes coupled to the network node in a network, the method comprising: receiving from each of the neighboring nodes an identifier and an indication as to whether synchronization resources have been assigned to the network node; comparing by magnitude the identifier of the neighboring node with identifiers of others of the neighboring nodes to determine whether to synchronize with the neighboring node; and, synchronizing with the neighboring node if the neighboring node has assigned synchronization resources to the network node.

Abstract: A system and method for providing link, node, and PG policy based routing in PNNI based ATM networks is disclosed. A computer implemented method signals and routes a call in the network. Upon detecting the call's arrival, its service request is accessed. Upon determining that the service request relates to an attribute of a link, a routing path is sought that conforms to the service request, as by accessing information relating to the routing path and comparing the information to the service request. A conforming routing path is selected, and the call is routed via that path. A computer implemented method advertises an attribute of links, nodes, policies, etc. Data relating to the route's attribute can be provided to a node as a GAT IE component of a PNNI signaling setup message for multi-peer group networks, and advertised using PTSEs within a peer group.

Abstract: A datagram network is operated by placing a group address in the source address field of the datagram. Nodes within the datagram network forward the datagram in dependence on the contents of the source address field. This provides many of the scalability advantages offered by Multiprotocol Label Switched (MPLS) networks without introducing the overheads caused by connection set-up in MPLS networks. The method can also easily provide different quality of service levels to different types of packets and is especially useful in providing Virtual Private Networks across a shared internetwork such as the public Internet.

Abstract: A system for, and method of, determining a physical topology of a network having multiple subnets. In one embodiment, the system includes: (1) a skeleton path initializer that uses addressing information from elements in the network to develop a collection of skeleton paths of direct physical connections between labeled ones of the elements, the skeleton paths traversing multiple of the subnets and (2) a skeleton path refiner, coupled to the skeleton path initializer, that refines the collection by inferring, from the direct physical connections and path constraints derived therefrom, other physical connections in the skeleton paths involving unlabeled ones of the elements.

Abstract: An apparatus and method includes grouping filters to form a tree according to a bitmask. The bitmask includes entries indicating whether a value is assigned to an element of a filter. The method also includes receiving a packet that includes a particular bitmask, searching the tree to determine filters associated with the particular bitmask and the associated values, and returning a set of filters that are an intersection of the filters indicated by the associated values.

Abstract: Methods, apparatus, data structures, computer-readable media, and mechanisms may include or be used with a hierarchy of schedules with propagation of minimum guaranteed scheduling rates among scheduling layers in a hierarchical schedule. The minimum guaranteed scheduling rate for a parent schedule entry is typically based on the summation of the minimum guaranteed scheduling rates of its immediate child schedule entries. This propagation of minimum rate scheduling guarantees for a class of traffic can be dynamic (e.g., based on the active traffic for this class of traffic, active services for this class of traffic), or statically configured. One embodiment also includes multiple scheduling lanes for scheduling items, such as, but not limited to packets or indications thereof, such that different categories of traffic (e.g., propagated minimum guaranteed scheduling rate, non-propagated minimum guaranteed scheduling rate, high priority, excess rate, etc.

Abstract: A method and apparatus for providing a hierarchical structure for routing over packet networks are disclosed. The method first receives one or more packets from at least one customer endpoint device with a Customer Edge (CE) functionality, wherein said one or more packets are destined for a destination node. The method locates a route for routing said one or more packets by consulting an interface specific routing table. The method then forwards said one or more packets towards said destination node using said route.

Abstract: A multi-node network that comprises a plurality of nodes, at least one of the nodes comprises a local cache for storing a plurality of matching indications at least some of which associated with a potential node. A receiving node of the plurality of nodes that is configured for receiving a matching request having a requested matching indication associated with an address of an additional node of the plurality of nodes. The receiving node is configured for identifying a match between the receiving node and at least one of the associated potential nodes by matching the requested matching indication and the stored matching indications and for informing one or more of the receiving nodes and the associated nodes about the match.

Abstract: Principles of the invention are directed to techniques for allowing a router forwarding packets within a computer network to perform two or more forwarding tree decisions per memory access. The router may implement forwarding information in the form of a radix tree having a number of nodes, and received packets may contain keys identifying a packet destination. The router may traverse the tree by testing two or more path control bits within the key per each of the traversed nodes. The values of the path control bits in the key determine the path traversed along the tree. The router also stores intermediate bit patterns at each node and tests intermediate bits in the key to determine whether a particular node is the best match to the routing prefix contained in the key, thereby eliminating a need to backtrack up the tree.

Abstract: A domain configuration system and method operable in an Ethernet OAM network having multiple levels of OAM domains. A port of a first end bridge of the network is configured as a first MEP node belonging to a predetermined OAM domain having a particular level. GARP or CC frames are transmitted from the first MEP node in a forward attribute registration process towards the remaining bridges of the network. A port of a second end bridge of the network is configured as a second MEP node of the predetermined OAM domain. In a backward attribute registration process, GARP or CC frames are transmitted from the second MEP node towards the remaining bridges of the network. Responsive to the frame flow, ports in bridges disposed between the first and second end bridges are automatically configured as MIP nodes having the particular level.

Abstract: A communication device (S) for an MPLS network comprises a signaling module capable of establishing a point-to-multipoint MPLS connection tree with a plurality of leaf nodes (A, B) by transmitting a connection request message and by receiving a reservation method in response, said connection request message comprising addresses of said leaf nodes and characteristics of downstream traffic in order to characterize the quality of service desired for a downstream data flow to transmit to said leaf nodes, said reservation message comprising a label for establishing a downstream MPLS connection. To bidirectionally establish the MPLS connection tree (15, 16, 17), the connection request message further comprises characteristics of upstream traffic in order in order to characterize the quality of service desired for upstream data flows to be received from said leaf nodes and a label for establishing an upstream MPLS connection.

Abstract: A preference programmable first-one detector and quadrature based random grant generator in a crossbar switch is disclosed. The crossbar switch emulates a FIFO switching function in a single chip crossbar switch architecture that operates at a high switching speed with a large bandwidth and supports multiple QoS levels, yet do not demand an inordinately large number of input and output queues or otherwise excessively tax memory requirements. The system and method operate at a high switching speed with a large bandwidth and support multiple QoS levels, yet do not require a complex pointer management system, nor constrain switching speeds and bandwidth capacity therein. The system and method efficiently select data for switching within a crossbar switch based structure based on an urgency counter based WRR grant selection. This switching is achieved with economy of hardware by quadrature basing and quadrature preference selection.

Abstract: A method to provide a loop-free telecommunication network comprising end-users interconnected through one or more Metropolitan Area Network and/or Wide Area Network providing Virtual Private Local Area Network Service (VPLS) and possible geographically dispersed Layer-2 networks (K, L) is provided. To prevent the VPLS-networks from creating loops, a predetermined protocol, e.g. the Rapid Spanning Tree Protocolis used. Internal node ports of each node of a VPLS-network are grouped into a port arrangement in order to model a virtual LAN inside the VPLS-network. For each port arrangement, the sum of weight factors or port Path Cost towards a root bridge is calculated, the node having an external node port with the lowest port path cost is selected as the primary node, and the paths of the other external node ports towards the root bridge are disabled. In case two or more nodes of a VPLS-network have an identical port path cost, the node number or node ID for selecting the primary node is taken into account.

Abstract: A data packet routing mechanism including a plurality of clients for issuing read requests to a host device, the read requests each including a TAG field for identifying which of the plurality of clients issued a particular read request, wherein a completion response corresponding to the particular read request, including the TAG field, is issued from the host to the client that sent the read request, the plurality of clients being organized into M groups, each group including a predetermined number of clients; a first level routing device having an input for receiving completion responses from the host and a plurality of outputs for transmitting completion responses; and a plurality of second level routing devices, each being coupled to the plurality of clients in one of the M groups, and having an input for receiving completion responses from the first level routing device and a plurality of outputs, each output for transmitting completion responses to one of the plurality of clients in the group.

Abstract: A layer 2 loop detection apparatus includes a unit recognizing a topology of an L2 network at normal time by collecting MIB information including information concerning ports of a plurality of L2 switches from the plurality of L2 switches through SNMP communication; a unit discriminating, based on a topology recognition processing, a blocking port for traffic blocking and a disable port under a port disable state each set under a Spanning Tree Protocol (STP); a unit setting each of the blocking port and the disable port as a monitoring point and periodically monitoring a state thereof; and a unit performing detection of an L2 loop by re-collecting a part of the MIB information from the plurality of L2 switches through SNMP communication and re-recognizing the topology of the L2 network, the detection of the L2 loop detection being triggered by a change of a state of one of the blocking port and the disable port.

Abstract: There is provided a method for determining reachability between any two nodes within a graph. The inventive method utilizes a dual-labeling scheme. Initially, a spanning tree is defined for a group of nodes within a graph. Each node in the spanning tree is assigned a unique interval-based label, that describes its dependency from an ancestor node. Non-tree labels are then assigned to each node in the spanning tree that is connected to another node in the spanning tree by a non-tree link. From these labels, reachability of any two nodes in the spanning tree is determined by using only the interval-based labels and the non-tree labels.

Abstract: Network topology codes are computed and used as keys to retrieve topology-specific information for isomorphic networks.

Abstract: In a forwarding device connected to a network including a plurality of communication nodes connected to each other, in which a plurality of communication routes, each for forwarding a signal through at least one of the communication nodes can be present between arbitrary ones of the communication nodes, a forwarding method according to the present invention determines that the received packet is a BPDU or a local BPDU, and discards the BPDU if the received packet is the BPDU and fetches an original BPDU from the local BPDU if it is the local BPDU. In the case where the BPDU is to be transmitted, the BPDU is created and wrapped in a format of the local BPDU. Then, the wrapped BPDU is broadcasted. In this manner, the local BPDU can be exchanged without affecting the other bridges having a normal spanning tree function.

Abstract: A method, system, and program for accessing data processing systems behind a NAT enabled network are provided. According to one aspect of the present invention, a NAT data processing system is located behind a NAT enabled network with a NAT device as a gateway to the NAT enabled network. A client system located outside the NAT enabled network queries the NAT device for the address of the NAT data processing system located behind the NAT enabled network. The query is automatically routed through the NAT device to a DNS server. The DNS server then returns an address for the NAT data processing system and source routing for the NAT device. The NAT device forwards the address and source routing to the client system. Then, the client system sends packets to the NAT data processing system at the address with source routing through the NAT device, such that the NAT data processing system behind the NAT enabled network is directly accessed by the client system from outside the NAT enabled network.

Abstract: In one embodiment, a method comprises registering, by a first label switching router having been identified as a root of a prescribed transport tree for transport of a prescribed group of data packets, at least two next hop label switching routers as belonging to the prescribed transport tree based on receiving respective label mapping messages; detecting by the first label switching router a prescribed condition indicating the first label switching router is to be removed from service as the root of the prescribed transport tree; and outputting, by the first label switching router, label distribution protocol messages for the prescribed transport tree to each of the next hop label switching routers determined as belonging to the prescribed transport tree, each label distribution protocol message indicating the first label switching router is to be removed from the service as the root of the prescribed transport tree.

Abstract: A method for configuring routing devices in a network data processing system. A routing change is identified in the network data processing system. In response to the routing change being identified, a node topology is generated for a set of routing devices present in the network data processing system. A master network configuration table is built at a routing device within the set of routing devices. The network configuration table contains configuration data from the routing devices in the node topology. The master network configuration table is broadcast to the routing devices in the network data processing system.

Abstract: A method and communication network for transferring data is described. For the method, responsive to executing first code in a first node in a communication network, the first node establishes a communication channel with a second node, replicates itself to generate second code, and provides the second code to the second node over the communication channel. Responsive to executing the second code in the second node, the second node establishes a communication channel with a third node, replicates itself to generate third code, and provides the third code to the third node over the communication channel. The second node then receives data from the first node over the communication channel and executes the second code to handle the data. The third node then receives the data from the second node over the communication channel and executes the third code to handle the data.

Abstract: A path management device of the present invention manages information about communication paths in a communication network, the communication network including a plurality of routers mutually connected by means of a communication line, link states between the plurality of routers being shared among each of the plurality of routers by means of link state advertisement messages that are announced from each of the plurality of routers, and routing tables being created in each of the plurality of routers based on shortest path trees, and the path management device includes: a receiving unit that receives the link state advertisement messages; a routing table creation unit that reproduces the shortest path trees and the routing tables of each of the plurality of routers based on the link state advertisement messages; and a routing table recording unit that records the reproduced routing tables of each of the plurality of routers.

Abstract: Sensor network routing uses distance information of sensors relative to a collector node, optionally along with non-unique key information, to route broadcasts from addressless sensors to a selected addressless collector. Distance calculation messages (DCMs) are used to set distance values on sensors relative to collectors. The distance values enable messages to propagate toward collectors to reduce the number of broadcasts. Self-assigned key information may be added to DCMs propagating in the network to enable routes to be determined through the network without assigning addresses to the participants. By storing the key information associated with the route, and causing sensors to only rebroadcast a message if the message contains a matching key at the matching distance position, broadcast paths may be created on the network. Optionally, diverse collectors and paths may be selected on the network by exchanging traffic condition indications and preferentially selecting paths with better traffic conditions.

Abstract: A network integrated management system transferring monitor/control information by e-mail using the Internet (40) between a monitor/control apparatus (50) having a network (14) to be monitored and controlled under it and a network integrated management apparatus (30) integratedly managing the network through the monitor/control apparatus.

Abstract: A network route tracing system traces a path through a network and identifiesnetwork components and communications links affected by the path. According to one embodiment of the present invention, a route is traced between two hosts in a network. The network is represented as a logical tree having a plurality of nodes. Each one of the nodes corresponds to a component in the network and each non-root node has a parent node. Two nodes are identified in the logical tree. A first node corresponds to a first host and a second node corresponding to a second host. If one of the two nodes exists at a lower level of the logical tree, then a first path is traced from the first node at the lower level to the parent node at a higher level until the parent node is at a same level of the logical tree as the second node. The first path is further traced up the logical tree from the parent node and a second path is traced up the logical tree from the second node until the first path and the second path meet at a same node.

Abstract: A system and method are provided to prevent the formation of loops in a network. The network device includes a plurality of ports for receiving and forwarding network messages and a spanning tree protocol engine. The spanning tree protocol engine, in one embodiment, implements the Rapid Spanning Tree Protocol (RSTP) to transitions the ports among a plurality port states, including a discarding state, a learning state and a forwarding state. The network device further includes a loop guard engine that is in a communicating relationship with the spanning tree protocol engine and the ports. The loop guard engine monitors the receipt of bridge protocol data units (BPDUs) by the ports. If a given port stops receiving BPDUs, the loop guard engine prevents the spanning tree protocol engine from transitioning the given port to the forwarding state. Instead, the loop guard engine causes the port to transition to loop inconsistent state.

Abstract: An initiator node in a local cluster included in a wireless network receives an admission request to execute an application comprising a set of tasks. If the initiator node is unable to map the set of tasks to nodes included in the local cluster, the local cluster head node forwards the admission request to the cluster head node of successive clusters in the wireless network in order to have at least one node in each of the successive clusters send resource availability information to the initiator node. The initiator node attempts to map the set of tasks to a subset of the nodes from which resource availability information has been received. This is repeated until the initiator node is able to map the set of tasks to a subset of the nodes in the wireless network or until there are no additional clusters to forward the admission request to.

Abstract: 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.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: The specification describes techniques for evaluating important network performance parameters, for example, call set-up time, for private network-to-network (PNNI) interfaces. These performance parameters are used to determine the optimum size of the peer groups in the PNNI network. Both flat and multi-level networks may be designed using the methods described.

Abstract: A node device having a plural hierarchy levels in a tree-like shape while placing a broadcast device at a top of the levels and connecting the node devices through a communication means, wherein content data is sequentially transferred from the node device at an upper hierarchy level to that at a lower hierarchy level, including: a control means for displaying a predetermined screen for a user; and a means for carrying out a process of participating in the system when a broadcast information screen related to broadcast of the content data is displayed and for carrying out a process of withdrawing from the system when display is finished, wherein when transiting to display in another screen, the participation and withdrawal control means carries out the withdrawal process on a condition that the broadcast information screen is not displayed again within a waiting time previously set up.

Abstract: An information packet preclassification system and method are provided. The method receives a packet of information and differentiates the packet into segments. Using a decision tree with multiple levels, segments in the packet are compared to a node at a tree level, where each node includes a plurality of node reference segments and corresponding node comparison operators. The reference segment may be a different segment from the packet, or a predetermined segment value stored in memory. One, or more classification attributes are accessed in response to comparing segments, and the classification attributes are assigned to the packet. Then, the packet is processed in response to the classification attributes.

Abstract: Shortest-path spanning trees are created outward from each portal on a Rbridge network with nodes on the network being assigned to the spanning trees. For those nodes equidistant to two portals, an election process is used to determine which tree the node should join. To enable routes associated with nodes on the Rbridge network to be distinguished from routes external to the Rbridge network, messages may be transmitted between the portals. The messages enable portals to identify routing updates received from the external network as containing internal routes, so that traffic that is required to pass between nodes on different trees may pass over the Rbridge network rather than over the external network.

Abstract: Described is a method for managing flow of protocol information in a node of a hierarchical network in which the protocol information is communicated between network nodes in topology state elements. The method comprises checking topology state elements generated by the node to identify protocol information encapsulated therein, and selectively allowing transmittal of the topology state elements from the node to lower levels of the network based on the protocol information identified.