Abstract: A system and method are provided for providing both static and dynamic IP multicasting. When a router receives a PIM message or an IGMP message, the router determines whether the group specified in the message is within the multicast Static-Range. If the group pertains to a static multicasting group, the router does not propagate the message to upstream routers and only connects or disconnects interfaces internal to the router. If the multicast group address in the message is not within the multicast Static-Range, the router implements PIM or IGMP protocols. If the invention is used for broadcasting TV, the low end of TB channels or commonly used channels can be created as static IP multicast. This way, a user can access or leave such channels without an entire shortest path tree being created or torn down, improving access time and channel surfing for a user.

Abstract: A method for convergence of multicast traffic in response to a topology change. The method includes, in response to a change in a multicast topology, redirecting multicast traffic through a network device of a plurality of network devices in the multicast topology and determining a querier status of the network device. The method also includes flooding the multicast traffic through an interface to the network device to facilitate convergence of the multicast traffic. The interface is a connecting point between the network device and another network device of the plurality of network devices.

Abstract: Distribution of content between publishers and consumers is accomplished using an overlay network that may make use of XML language to facilitate content identification. The overlay network includes a plurality of routers that may be in communication with each other and the publishers and consumers on the Internet. Content and queries are identified by content descriptors that are routed from the originator to a nearest router in the overlay network. The nearest router, for each unique content descriptor, generates a hash identification of the content descriptor which is used by remaining routers in the overlay network to provide the appropriate functions with respect to the content descriptor. In particular, this allows all routers in the overlay network except the nearest router to properly route content without processing every content descriptor.

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: A pair of Redundant Multicast Trees for each multicast connection connects the source of a multicast LSP to all its destinations in such a way that, in the event of a single link or node failure in the network, every destination node is still connected to the root node in at least one of the two trees. Furthermore, a method ensures that existing Redundant Multicast Trees can adapt to changes in the set of destination nodes and/or network topology changes without significant modifications.

Abstract: Communication between clusters of processing nodes is initiated by designating a link layer address and a target node name in a remote cluster. The link layer address is transmitted to the target node via a regular network transmission. The link layer address is stored locally in each cluster and the nodes in each cluster are signaled that a configuration change has been made, so that gateway nodes in the clusters can obtain the link layer address to use for subsequent communications with the other cluster, such as event notifications of node status changes.

Abstract: Techniques are disclosed for discovery and tracking of locations of devices attached to a computing system network. By way of example, an automated method for determining a location of a target element in a distributed network includes the following steps. One or more locations of one or more sample topology elements in the distributed network are learned. Location mappings are generated, the location mappings representing associations between the learned locations of the one or more sample topology elements and one or more network attributes. A location of a target element is estimated using the location mappings.

Abstract: A set of critical nodes or links is identified on the network and alternate forwarding state is pre-computed and disseminated within a node such that, upon failure of one of the critical nodes/links, a minimal trigger will cause the alternate forwarding state to be used to forward traffic on the routed Ethernet mesh network. In one embodiment rather than storing full tables of alternate forwarding state, only the changes to the forwarding state required by an identified failure is stored by the network nodes. Upon occurrence of a failure on the network, the identified failure is used to select the alternate forwarding state.

Abstract: Described are a method and a sensor aware network for dynamic processing of sensor data. Network context data are inserted into data packets from sensors or local sensor networks coupled to the sensor aware network. Sensor aware nodes in the sensor aware network can read the context data and can respond by performing specific network actions. The sensor data and network context data are provided to one or more application nodes. The sensor data and network context data can be stored in a database and later searched according to the network context data. Advantageously, sensor data flows can be treated differently by the sensor aware network, the application and the user, depending on the type of sensor data and the actual data values. Thus critical responses to certain sensor data flows can be implemented more efficiently than otherwise possible using conventional network configurations.

Abstract: In an example embodiment, a topology based channel assignment method for mitigating contention between overlapping radio coverage areas in a wireless “mesh” network topology. A central controller compiles radio overlap information and executes a Tiered Graph Coloring Algorithm, which is used to mitigate contention between overlapping radio coverage areas. In general, the radio channel for each Channel Assignment Cluster (Basic Service Set) is selected so that the aggregate radio coverage area of the Channel Assignment Cluster does not overlap with the radio coverage areas of neighboring Channel Assignment Clusters and fixed interference sources. In the tiered algorithm, a Channel Assignment Cluster is represented as a single vertex, interference sources are represented as “fixed” vertices with fixed color assignments, and “overlapping” vertices are interconnected by “edges.” Vertices are “tiered” so that overlap mitigation is prioritized for higher-traffic radios.

Abstract: A Flow Transport and Delivery Network (FTDN) supports delivery and transport of flows to destination nodes over parallel overlay networks. Overlay nodes executing overlay processes create and maintain one or more overlay networks. A plurality of sites are connected to each other via the parallel overlay networks with each site comprising one or more transit routers that route the flows to the destination nodes.

Abstract: A method for efficient propagation of link state advertisements in densely interconnected OSPF networks is disclosed for reducing the number of duplicate LSAs propagated during a flooding event. The efficient propagation method includes calculating an LSA propagation subgraph which is used by a node which receives an LSA to determine which links to propagate the LSA upon. This allows a significant reduction in the LSAs which traverse the network during a flooding event. The reduction in LSAs is particularly useful for reducing network convergence times associated with flooding events. In addition, a system is disclosed for performing the method in both a centralized and dispersed manner.

Abstract: An apparatus includes a memory configured to store multiple route descriptors as a tree, a communications interface configured to be in communication with an access switch, and a processor operatively coupled to the memory and the communications interface. Each route descriptor is a node within the tree, and includes a next hop destination associated with a next hop destination of a route associated with that route descriptor and a next hop indicator associated with a quantity of routes represented by that route descriptor. A first route descriptor has a first child route descriptor and a second child route descriptor. The processor is configured to define, at a first time, a value of the next hop destination of the first route descriptor and to send, at a second time after the first time, the value of the next hop destination of the first route descriptor to the access switch.

Abstract: MAC protocol selection is described. In a communication system, a MAC protocol is automatically selected from a set of MAC protocols based on a connectivity graph of at least part of the communication system.

Abstract: A system and method of operating a wireless network having a plurality of nodes. Each node determines whether to replace the beacon node. When a node determines that the beacon node is to be replaced, the node determines whether it should nominate itself as a potential replacement beacon node. The decision whether to nominate itself as a potential replacement beacon node is a function of a random number generated by the node. If the node determines that it should nominate itself as a potential replacement beacon node, the node sends out one or more beacon signals. Beacon signals are received by potential replacement nodes and, if the potential replacement beacon node has received a beacon signal from a higher ranking potential replacement beacon node, the node removes itself as a candidate for the replacement beacon node.

Abstract: In one embodiment, a management device, such as a root node, monitors Internet Protocol (IP) overhead (e.g., IP header sizes during source-routing or route table sizes) within a directed acyclic graph (DAG) in a computer network. If it is determined that the IP overhead is above a configured threshold, then in response, a trigger is initiated to have devices within the DAG label-switch downward traffic directed away from the root node within the DAG. In another embodiment, a device communicating within a DAG stores IP routes corresponding to upward traffic from the device directed toward a root of the DAG, and IP-routes upward traffic based on the IP routes. Conversely, the device also stores labels corresponding to downward traffic from the device directed away from the root of the DAG, and label-switches downward traffic based on the labels, accordingly.

Abstract: A supervisor entity comprises an entity status module for maintaining status of its subordinate entities and updating the supervisor entity with status updates for itself and the subordinate entities. The entity status module comprises an entity status controller for receiving a status message from a first subordinate entity, a subordinate determination module for determining a second subordinate entity that is subordinate to the first subordinate entity, a status update module for updating the status of the second subordinate entity based on the received status message from the first subordinate entity, a status reporting module for reporting the updated status of the second subordinate entity to a supervisor entity and a status storage for storing the status of the second subordinate entity.

Abstract: Described embodiments provide for arbitrating between nodes of scheduling hierarchy of a network processor. A traffic manager generates a tree scheduling hierarchy having a root scheduler and N scheduler levels. The network processor generates tasks corresponding to received packets. The traffic manager queues the received task in an associated queue of the scheduling hierarchy. The root scheduler performs smooth deficit weighted round robin (SDWRR) arbitration between each child node of the root scheduler. The SDWRR arbitration includes checking one or more status indicators of each child node of the given scheduler and selecting, based on the status indicators, a first active child node of the scheduler and updating the one or more status indicators corresponding to the selected child node. Thus, a task is scheduled for transmission by the traffic manager every cycle of the network processor.

Abstract: A sensor node identification method by a first component of a first layer in a hierarchical sensor network includes: receiving a sensing request including sensor node identification information from a second component of a second layer prior to the first layer; modifying the sensor node identification information by removing an identifier of the first layer from the sensor node identification information when an identifier of the first layer matches an identifier of the first component among the sensor node identification information; and transmitting a sensing request including the modified sensor node identification information to a third component of a third layer subsequent to the first layer.

Abstract: Methods and apparatus for enabling output from a mobile device are described herein. A mobile device having an image capture device can selectively generate a hard copy output of a captured image by interfacing with an output device. The mobile device can selectively interface with the output device directly or indirectly via one or more intermediate devices and/or systems. The mobile device can interface directly with an output device using a wired or wireless connection, and can selectively operate as a host or client. The mobile device can selectively couple the stored image to a remote output device via a wireless connection. The mobile device can select the remote output device from a predetermined list of devices, or can be supplied a dynamic list of remote output devices. The dynamic list of output devices can be updated, for example, based on a location of the mobile device.

Abstract: Techniques for efficiently updating routing information in a network device such as a router. According to an embodiment of the present invention, information is stored identifying one or more nodes and leaves owned or advertised by the nodes. When a change occurs in a network environment, information is stored identifying one or more nodes and leaves that have changes associated with them. The routing information in the network device is then updated for only those nodes and leaves that have changes associated with them.

Abstract: Performing a scatterv operation on a hierarchical tree network optimized for collective operations including receiving, by the scatterv module installed on the node, from a nearest neighbor parent above the node a chunk of data having at least a portion of data for the node; maintaining, by the scatterv module installed on the node, the portion of the data for the node; determining, by the scatterv module installed on the node, whether any portions of the data are for a particular nearest neighbor child below the node or one or more other nodes below the particular nearest neighbor child; and sending, by the scatterv module installed on the node, those portions of data to the nearest neighbor child if any portions of the data are for a particular nearest neighbor child below the node or one or more other nodes below the particular nearest neighbor child.

Abstract: Methods and apparatus are provided for self-organized caching in a content delivery network. One or more requested content items are cached at a node in a content delivery network. The disclosed method determines if the content item is stored in a local cache; and, if the content item is not stored in a local cache, the following steps are performed: requesting the content item from another node; and storing the content item in the local cache it one or more predefined capacity criteria are satisfied. The content delivery network can be a hierarchical network or a non-hierarchical network. The predefined capacity criteria can evaluate a popularity index of the content item relative to other items stored in the local cache.

Abstract: A wireless communication network, including a destination node, a first node transmitting a first routing message, wherein the first node has a first routing table including a first entry for the destination node, and the first entry includes a first list field for child node(s). The network further includes a second node generating and transmitting a second routing message according to the first routing message, wherein the second routing message includes a second parent node field, and the second parent node field is marked as the first node that transmitted the first routing message. The first node further receives the second routing message and stores a first mark in the first list field for child node(s) of the first entry after determining that the second parent node field of the second routing message is marked as the first node, and the first mark denotes the second node.

Abstract: A method for performing user security operations using a mobile communications device includes, storing at least one security credential for a user in the mobile communications device, receiving a request from a client computer to perform an action requiring the stored at least one security credential, wherein the request includes information regarding a service application for which the action is requested, determining a response to the request based upon at least one user configured personal security preference at the mobile communications device, and transmitting the determined response to the client computer. Corresponding system and computer program products are also described.

Abstract: A router maintains routing information including (i) route data representing destinations within a computer network, (ii) next hop data representing interfaces to neighboring network devices, and (iii) indirect next hop data that maps a subset of the routes represented by the route data to a common one of the next hop data elements. In this manner, routing information is structured such that routes having the same next hop use indirect next hop data structures to reference common next hop data. In particular, in response to a change in network topology, the router need not change all of the affected routes, but only the common next hop data referenced by the intermediate data structures. This provides for increased efficiency in updating routing information after a change in network topology, such as link failure.

Abstract: A solution is provided wherein the interfaces between multiple chassis (e.g., edge switches) in a network of layer 2 devices and a spanning tree device are treated as a single emulated switch. This emulated switch effectively enables two different views to the two different sides. Thus, frames from the network of layer 2 switches destined to any port of the emulated switch may take any of the links (through any of the physical switches), thereby enabling effective load-balancing for frames traveling from the layer 2 network side into the spanning tree device. Meanwhile the spanning tree device does not recognize an illegal loop in its connection to two different edge switches as it views the two links as a single logical EtherChannel.

Abstract: A multicast message may be distributed by receiving, at a first node in a multicast network, a multicast message from a parent node of the first node. The multicast message is transmitted to child nodes of the first node in the multicast network. A population of the child nodes to which the multicast message was transmitted is accessed and acknowledgement messages which reveal child nodes that are among an acknowledging subset of less than all of the child nodes of the first node are received. Child nodes revealed by the received acknowledgement messages are compared with child nodes determined to be among the population of child nodes to which the multicast message is expected to be received. Based on results of the comparison, a compressed non-acknowledging subset is identified and transmitted to the parent node.

Abstract: A structured wireless mesh network is disclosed where a tree-like connection topology is formed. In one embodiment, each node has separate uplink and downlink radios operating on different channels. When a cluster of such nodes becomes isolated as in the case of a mobile mesh application, a node in the cluster according to this invention acts as a root node thus enabling the tree structure to persist, even in isolation. Example methods of joining sub networks are disclosed that guide the joining of mesh networks and channel management. Nodes that may operate in isolation also support a distributed DHCP capability such that IP addresses are assigned to clients even when a connection to a central DHCP server is unavailable.

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: In one embodiment, a method comprises attaching, by a mobile router, to an attachment router according to a protocol requiring establishment of a tree topology having a single clusterhead, the attaching by the mobile router based on the mobile router receiving, from the attachment router, an advertisement message specifying an attachment prefix; outputting a second advertisement message specifying availability of a prescribed address prefix used by the mobile router, and further specifying attributes of the mobile router relative to the tree topology; receiving a plurality of sensor data messages from at least one attached sensor host node, each sensor data message specifying at least one sensor data element specifying a detected sensor parameter; aggregating the sensor data elements from the sensor data messages into aggregated sensor data; and generating and outputting a neighbor advertisement message to the attachment router, the neighbor advertisement message specifying the aggregated sensor data.

Abstract: A method and a utility to assist configuration of high complexity hierarchically and deeply channelized telecommunication systems using a network language configuration application program interface. The invented method and utility removes major complexity from the process of configuring such devices and systems by accepting a minimal high level description of the required configuration, including an input language used for defining rules and requirements.

Abstract: An efficient media streaming method utilizing a globally load balanced overlay network. This method makes use of capacity per out-degree values to construct and maintain an overlay network for media streaming in a Peer-to-Peer environment.

Abstract: A method for performing node traversal operations of a treelet-composed hierarchical structure includes allocating a queue for each of the plurality of treelets, each queue operable to store ray-states entering a respective one of the treelets. The method additionally includes determining that a ray-state exits a first treelet of the hierarchical structure and enters a second treelet of the hierarchical structure. The method further includes forwarding the ray-state entering the second treelet to a processing element for processing therein, wherein the queue allocated to store ray-states entering the second treelet is bypassed.

Abstract: Embodiments of the invention include a method performed by a bank aware mtrie control module for distributing a plurality of mtrie levels across a plurality of memory banks. The bank aware mtrie control module identifies the plurality of memory banks present and identifies one or more mtrie blocks in one or more mtrie levels, each mtrie block is an array of mtrie nodes associated with an mtrie level. The bank aware mtrie control module stores each mtrie block in one of the plurality of memory banks, all mtrie nodes in a given mtrie block are stored in the same memory bank. For each subsequent mtrie level, the bank aware mtrie control module ensures that each of the mtrie blocks in that mtrie level is stored in one of the plurality of memory banks other than the memory bank storing mtrie blocks of an immediately previous mtrie level.

Abstract: A design and proof of concept of a new type of WLAN, complete with simulation and results from the simulation has been described. Each AP Node is implemented as a self-contained embedded OS unit, with all algorithms resident in its Operating system. The normal day-to-day functioning of the AP node is based entirely on resident control algorithms. Upgrades are possible through a simple secure communications interface supported by the OS kernel for each AP node.

Abstract: A method is provided for searching a route of a mobile node in a short-range communication environment. A first router to which a mobile node belongs acquires a unique address of the mobile node for communication with the mobile node. The first router determines whether the mobile node travels during communication. When the mobile node travels, the first router broadcasts the unique address of the mobile node to one or more neighboring routers and determines whether the one or more neighboring routers include the mobile node. If a second router, which is one of the one or more neighboring routers, includes the mobile node, the second router performs communication using the unique address without an additional address acquisition process.

Abstract: Embodiments of the present invention provide a method and a node device for transferring a message based on MPLS TE tunnels. The main principle of the embodiments is to determine a switching node at which MPLS TE tunnel switching is needed, and to set routing and forwarding information for tunnel switching between different MPLS TE tunnels at the switching node. The switching node switches and transfers message into different MPLS TE tunnels according to the routing and forwarding information. The present invention makes the sum of the whole network edge bandwidth resources much higher than that of the bandwidth resource at the network core, allows the network resources to converge layer by layer, and avoids the N-square problem of the tunnel number effectively and lightens the load on the network core nodes by the large number of tunnels and the load of RSVP-TE state refreshing.

Abstract: A scheduler in a network element may include a dequeuer to dequeue packets from a set of scheduling nodes using a deficit weighted round robin process, where the dequeuer is to determine whether a subset of the set of scheduling nodes is being backpressured. The dequeuer may set a root rich most negative credits (MNC) value, associated with a root node, to a root poor MNC value, associated with the root node, and set the root poor MNC value to zero, when the subset is not being backpressured, and may set the rich MNC value to a maximum of the root poor MNC value and a root backpressured rich MNC value, associated with the subset, and set the root poor MNC value to a root backpressured poor MNC value, associated with the subset, when the subset is being backpressured.

Abstract: A method of operating an Internet protocol (IP) address allocates, creates, and processes an interface identifier (ID) of an IP address area. In the allocation, the IP address area includes a subnet prefix area and an Interface ID area, and certain bits of the Interface ID area are used as an index area of a subnet gateway. The allocation is implemented in order from the higher layer to the lower layer so that the Interface ID area is sequentially allocated from the higher bits for the index areas of the respective layers. The combination of the certain bits of the allocated Interface ID and the subnet prefix area of the IP address area is used as the subnet ID of the subnet layers. The lowest subnet gateway allocates the Interface ID to terminating equipment to access the IP network based on a format of the IP address.

Abstract: A first Multi Protocol Label Switching (MPLS) Internet Protocol (IP) data network transmits data to a second MPLS IP network via a legacy network, which would not otherwise be able to handle the required user network interface (UNI) protocol by configuring the legacy network and its network management system (TNMS) so that they emulate an MPLS network. When a first network element (NE) receives a connection (UNI) request from the MPLS network under a UNI protocol, the UNI request is passed to the TNMS, which then sets the required connection across the legacy network via a second edge NE to an NE of the second network. Once the connection has been set, the TNMS instructs the edge NE to send a return signal to the requesting network indicating that the connection has been successfully set. Data packets may then be transmitted across the network.

Abstract: A system and method can support routing packets between a plurality of switches in a middleware machine environment, thereby supporting Internet Protocol (IP) based management traffic via enabling IP over Infiniband (IPoIB) communication in the middleware machine environment. The plurality of switches can perform routing for inter-switch traffic in the middleware machine environment using a first routing algorithm. Then, a switch in the middleware machine environment can be selected as a hub switch for inter-switch traffic that can not reach destination using the first routing algorithm. Furthermore, a routing table associated with the hub switch can be updated when a path exists between a source switch and a destination switch via the hub switch.

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: A packet network device includes a route processor that operates to maintain one or more forwarding tables and it includes one or more line cards that operate to process information received by the packet network device from the network and to forward the information to its correct destination. The route processor also operates to identify which incoming prefixes can be used to update the forwarding tables or to identify prefixes stored in the packet network device that can be redistributed from one network protocol to another network protocol running on the route processor. A table management function running on the route processor operates to identify the best match between an incoming prefix and information included in policy statement associated with both an ordered prefix-list and a radix tree structure.

Abstract: Serial networking dedicated fiber optic inflight entertainment (IFE) systems, methods therefor and components thereof, that exhibit improved configuration and failover attributes through implementation of novel network configuration protocols. In some aspects of the invention, such an IFE system comprises a plurality of head end line replaceable units (HE-LRUs) and a plurality of serial networking line replaceable units (SN-LRUs), wherein each of the SN-LRUs individually detects that a closed system network has been formed between the plurality of HE-LRUs and the plurality of SN-LRUs based on a plurality of packets sourced by at least one of the HE-LRUs and received on a plurality of ports of each of the SN-LRUs, and wherein in response to detecting that the closed system network has been formed one of the SN-LRUs blocks one of its ports based on further detecting that the SN-LRU is a middle SN-LRU.

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

Abstract: In one aspect, a method for error detection in a packet-based message distribution system, according to which messages are distributed via a plurality of nodes and other system components, and each node comprises at least two addressable interfaces is provided. For the security of the system, the message distribution paths are designed in a redundant manner and redundancy paths are available in the message distribution system in the event of the breakdown of connections in the message distribution system. The invention topology of the message distribution system is known by the nodes, and the nodes check the accessibility of the other nodes by means of communication tests; interrogate intermediate system components by means of existing interfaces and in terms of the connection status thereof in relation to other nodes and/or system components, and signal optional error configurations, physical errors, and/or missing redundancy paths of the message distribution system.

Abstract: In one embodiment, a method and apparatus of controlling transmission of data packets in a communications network includes designating all networking devices in a portion of the communications network as either hubs or spokes, communicating a link-state advertisement to each connected hub and spoke in the portion of the communications network, computing a shortest path tree at all the hubs and the spokes based on the link-state advertisement, the computing including truncating the shortest path tree at the hubs only for links leading from the spoke to the hub, creating a routing table at each of the hub and the spoke based on the truncated shortest path tree, and transmitting the data packets in the communications network based on the link-state advertisement. The shortest path tree includes all data transmission routes in the tree except links leading from a spoke to a hub.

Abstract: A wireless communication method in a wireless communication apparatus, which can exchange data with another wireless communication apparatus via a wireless communication, searches for another wireless communication apparatus, and determines a function of the other wireless communication apparatus. The method selects a communication route required to wirelessly communicate with the other wireless communication apparatus in accordance with the function of the other wireless communication apparatus, and communicates data to the other wireless communication apparatus in accordance with the selected communication route.

Abstract: An E-Tree is disclosed which includes a root node associated with a Metro Ethernet network. The E-Tree includes a first Virtual Bridge (VB), associated with the root node, which is configured to process Ethernet traffic, and a second node associated with the Metro Ethernet network. The E-Tree includes a second VB, associated with the second node, configured to process Ethernet traffic and having a first connection between the first VB and the second VB. The second VB is configured to be able to send Ethernet traffic to the first VB via the first connection, if appropriate. In the event there is a second connection between the second VB and a third VB and the second connection has been assigned a down direction from the point of view of the second VB, the second VB is not permitted to send traffic received from the second connection to another connection which from the point of view of the second VB has been assigned a down direction.