Abstract: Embodiments of our technology provide a method, system, and media for presenting relevant information incident to attempting to present information that is unavailable by way of a website. One embodiment of the method includes receiving a request to present a desired web page, determining that the desired web page is unavailable for presentation, determining search criteria associated with the request, dynamically generating a second web page that includes search results that were obtained based on the search criteria, and presenting the second web page on a display device.

Abstract: A network node for communicating data packets secured with a security protocol over a communications network includes a host information handling system (IHS) and one or more external security offload devices coupled by a secure data link. The host IHS communicates state information about data packets, and the external offload security device provides stateless secure data encapsulation and decapsulation of packets using a security protocol. An external network interface controller or internal network interface controller communicates encapsulated data packets over the communications network to a final destination. Encapsulation and decapsulation of packets by the external security offload device reduces network latency and reduces the computational load on the processor in the host IHS. Maintaining state information in the host IHS allows hot-swapping of external security offload devices without information loss.

Abstract: A method of facilitating substantially simultaneous receipt of electronic content by a plurality of intended recipients is disclosed. The electronic content is encrypted. The encrypted electronic content is transmitted to the plurality of intended recipients. An acknowledgement packet is received from each of the plurality of intended recipients within a predetermined timeout period. A handicap time is calculated for transmitting a decryption key to each of the intended recipient based on a time associated with the acknowledgement packet last received. Decryption keys are transmitted to the plurality of intended recipients using a delay based on the handicap time, where a decryption key having a smaller handicap time is transmitted prior to a decryption key having a larger handicap time.

Abstract: The system and method for streaming media to a viewer and managing the media comprises an enhanced service routing processor (ESRP), a real time switch management system (RTSMS), a name routing processor (NRP), and a managed media switch (MMS). The RTSMS has a reservation system. The ESRP receives media from an owner, manages the media according to media rules and order rules defined by the owner, and distributes the media to one or more switches, such as the MMS, according to the media rules and the order rules. The RTSMS is configured to receive the media rules and to receive a viewer's media request via the reservation server. The reservation system of the RTSMS processes the media request according to the media rules and builds a reservation for the requested media. The RTSMS generates the reservation to the viewer and to the NRP. The NRP receives the reservation data from the viewer and from the RTSMS. The NRP processes the reservation data and locates an MMS that can stream the media to the viewer.

Abstract: The disclosure discloses a method and a system for establishing an associated bidirectional Label-Switched Path (LSP). The method includes the following steps: a head node sends a PATH message for establishing or updating an LSP to an end node, wherein the message carries an object for identifying association; the end node sends to the head node a PATH message for establishing or updating an LSP as a reverse LSP corresponding to the above LSP, wherein the message carries an object for identifying association; in the case that the attributes of the objects for identifying association carried in the PATH messages sent by the head node and the end node are the same, the LSP and the reverse LSP are associated with each other by the head node and the end node and become an associated bidirectional LSP.

Abstract: A host computer accesses a federated storage volume at first and second frames (physical storage assemblies). The host identifies a preferred frame by (1) obtaining representative values of a performance metric for sets of paths to the volume, each set associated with a different frame, and (2) selecting the frame associated with the path set having the best representative value. In one example a response latency is used to detect different distances to the host and identify the closer frame, which will be preferred. Operating modes of the paths for non-preferred frames are set to “standby”. During subsequent operation using path selection to send storage operations to the volume, the host selects among paths in an “active” operating mode so as to access the volume at the preferred frame under normal operating condition. Standby paths are reserved for less normal operating conditions, such as when no active path is available.

Abstract: Methods and systems for performing load balancing and session persistence in IP (e.g., IPv6) networks are described herein. Some aspects relate to a destination options extension header that may be defined as a load balancing session persistence option (LBSPO) for storing a client identifier and a server identifier for each of a client and a server during a session. Packets sent between the client and the server may include the LBSPO with the client and server identifiers. A load balancer with a virtual IP address of a target application can perform session persistence and assign a destination server to a client based on a preexisting session between the server and the client, as determined by the LBSPO information. While a target VIP node may process data packets based on the LBSPO information, once established, the LBSPO information may remain unchanged for the duration of the session.

Abstract: An access gateway containing IP telephone service functions for subscribers under an integrated access device (IAD), forming a PSTN network side speech path or IP network side speech path selectively for each subscriber, and, further automatically switching, when trouble occurs at the IP network side, the IP network side speech path to the PSTN network side speech path.

Abstract: A method for assisting the construction and validation of an avionics platform uses, on the one hand, a functional description of the platform using avionics functions, software modules suitable for executing these functions, and functional link occurrences between these modules and, on the other hand, a material description of this platform using calculation or communication items of equipment and physical links between these equipment. The method according to the invention enables to generate paths between the various items of equipment by using direct physical links and/or physical links belonging to one or more network(s), and subsequently to associate at least one such path to be each functional link occurrence. It also enables to associate to each software module an item of equipment adapted to host it.

Abstract: The invention relates to a system for remotely accessing a mass storage unit and a security storage unit in a portable communicating object. According to the invention, a terminal, such as a mobile device, which is associated with a portable communicating object, such as a multimedia smart card, includes an agent for facilitating access from a server to a mass storage unit capable of storing multimedia data and a security storage unit in the portable communicating object via a communication network. The agent establishes a single communication channel between the remote server and the terminal and processes data transmitted from one of the two elements including the server and one of the storage units of the portable communicating object to the agent so that the agent can transmit the data to the other of the two elements.

Abstract: An apparatus, method, and machine-readable medium are described for establishing, maintaining and utilizing backup channels in a peer-to-peer (“P2P”) network. For example, in one embodiment, each mobile device can establish a primary P2P communication channel with one or more other mobile devices. Once the primary channel is established, each mobile device can use the primary channel to exchange secondary channel connection data and can subsequently open one or more secondary P2P communication channels with the other mobile devices. Upon detecting that the primary P2P communication channel has failed or has degraded below a specified threshold (e.g., a bandwidth or bitrate threshold), one of the secondary P2P communication channels can be automatically promoted to a primary P2P communication channel.

Abstract: A system may include information handling system devices connected together to form a computing cluster utilizing a SCSI interface. Each one of the information handling system devices may include an operating system kernel having a SCSI networking module for encapsulating Internet Protocol (IP) packets for transmitting between the information handling system devices. The system may also include SCSI hardware for connecting the information handling system devices together. The SCSI hardware may be configured to transmit the encapsulated IP packets between the information handling system devices.

Abstract: A distributed mediation network and method of employing such is provided, having a plurality of different types of network module. Each module has a non-reciprocal path therethrough for network traffic and the distribution of network traffic across the network is managed by an autonomic control plane.

Abstract: A method is implemented in a network element functioning as a control node for a mobile node (MN) communicating with a corresponding node (CN). The method includes selecting a virtual agent in the network to provide mobility services to the MN. The virtual agent represents a set of mobile resources proximate to the MN. The virtual agent is selected such that the MN receives a better quality of service when communicating with the CN through the virtual agent. A provisioning message is sent to the selected virtual agent including parameters for a session between the MN and CN. The provisioning message initiates a flow redirection at the virtual agent. A provisioning acknowledgement message is received from the virtual agent indicating that the virtual agent is receiving data packets from the CN and forwarding the data packets to the MN at the care-of address.

Abstract: Method/system is disclosed for recovering computing capacity and critical applications after a catastrophic failure. The method/system involves distributing the computing capacity over multiple computing clusters, each computing cluster having concurrent access to shared data and software applications of other computing clusters. Sufficient backup computing capacity is reserved on each computing cluster to recover some or all active computing capacity on the other computing clusters. Message traffic throughout the computing clusters is monitored for indications of a catastrophic failure. Upon confirmation of a catastrophic failure at one computing cluster, the workloads of that computing cluster are transferred to the backup computing capacity of the other computing clusters. Software applications that have been designated for recovery are then brought up on the backup computing capacity of the other computing clusters.

Abstract: A packet transmitting apparatus according to the present invention includes a plurality of ports. When the same unlearned packets have arrived at the plurality of ports, the packet transmitting apparatus judges through packet processing section that the first arrived one of the packets is a previous arrival packet. Then, through previous arrival group judging section, the packet transmitting apparatus selects from the plurality of ports a plurality of ports satisfying a previous arrival port condition for determining a port at which the previous arrival packet arrives as a previous arrival port. The packet transmitting apparatus judges the thus selected plurality of ports as the previous arrival ports having an equal previous arrival characteristic of packets, and includes the ports in a previous arrival port group.

Abstract: Embodiments may include a load balancer that receives a request packet sent by a remote client to an original destination address of multiple network addresses serviced by the load balancer, and selects according to a load balancing protocol, a host computer of a plurality of host computers to process the request. The load balancer may, from among a plurality of ports on the selected host computer, select a particular port having a one-to-one association with the original destination address, the association specified by mapping information accessible to the load balancer, and send the request packet to the selected port on the selected host computer. The mapping information accessible to the selected host computer specifies a one-to-one association between the selected port and the original destination address. Sending the request packet to the selected port conveys that address to the selected server without that address being included in that packet.

Abstract: After statically provisioned paths are created through an Ethernet network, trunks may be created to extend along those paths. The trunks extend between pairs of NNI interfaces on either end of the path, and Ethernet OAM may be run over the trunks to detect connectivity along the paths. Service instances and service groups may be provisioned over particular paths through the network. Each service instance/service group is associated with a trunk and the Ethernet OAM service on the trunk may be used to provide Ethernet connectivity OAM for the service instance/service group. Upon detection of a failure on the trunk, the service instances/service groups associated with the trunk may be caused to failover to an alternate path through the network. Thus, a single Ethernet OAM service instance may be used to provide connectivity verification so that connectivity detection does not need to be performed on each individual service instances/service group.

Abstract: A method, apparatus and computer program product for performing optimized distributed routing for stretched data center models through updating route advertisements based on changes to Address Resolution Protocol (ARP) Tables is presented. Port members of an Internet Protocol I (IP) interface or Virtual Local Area Network (VLAN) are distinguished into Access Interfaces which only lead to hosts on said subnet and Trunk Interfaces which lead to other redundant routers on said subnet. In the subnet of a network a network route for the subnet is always advertised. A separate host route corresponding to an Internet Protocol (IP) address of each Address Resolution Protocol (ARP) table record that points to an Access Interface is advertised and route advertisements are changed for a host in said subnet for tracked access interfaces.

Abstract: A control apparatus comprises: a switch extraction unit extracting a second switch adjacent to a first switch that stops in a communication system including a plurality of switches having a predetermined topology; a flow extraction unit extracting a flow transferred to the first switch after the second switch from a plurality of flows passing through the communication system; a path determination unit determining, assuming that, among the plurality of switches, switches located at start and end nodes of the flow are third and fourth switches, respectively, a path from the second switch to the fourth switch, based on a topology obtained by excluding the first switch from the predetermined topology; and a path generation unit connecting a path from the third switch to the second switch in an initial path of the flow and a path determined by the path determination unit to generate a new path of the flow.

Abstract: A technique for configuring a computing system that allows for multiple computing systems and device populations to be supported by a single BIOS implementation is presented. In one embodiment, the technique includes processing topology map parameters that describe physical connections of a computing system, wherein the computing system includes a plurality of processing nodes; determining routing paths for traffic between the plurality of processing nodes; and determining a population of the plurality of processing nodes. In one embodiment, the determining the routing paths is performed during BIOS build time. In another embodiment, the determining the routing paths is performed during BIOS run time.

Abstract: System, methods, and networks are disclosed that allow base station systems of a wireless communication network to transmit outgoing traffic over a packet backhaul network to multiple routing elements on the MSC side of the network. A base station system described herein identifies a primary routing element and a backup routing element. The primary routing element is the device to which the base station system transmits outgoing traffic under normal operation, and the backup routing element is an alternate to the primary routing element. To transmit traffic over the packet backhaul network, the base station system monitors the availability of the primary routing element. If the primary routing element is available, then the base station system transmits outgoing traffic over the packet backhaul network to the primary routing element. If unavailable, then the base station system transmits outgoing traffic over the packet backhaul network to the backup routing element.

Abstract: A system for displaying files over a local area network or over the Internet. The method includes the steps of defining headings for either non-comparative information or comparative information within any company or government entity or within any vertical market, listing either hierarchical information or the products or services of vendors in a vertical market, including vendors that do not have a Web presence, and providing a means of soliciting products or services or other information not listed. The step of displaying files eliminates the wait for the latency period of successive server round trips after the first server round trip, saving user functional engagement time. The method allows the user to disconnect the user computer from the Internet once all database information files are downloaded, and, since any subsequent information files viewed are resident in the user computer, the current method is faster than existing methods.

Abstract: A method for solving the reconfiguration planning problem transforms the requirement that an invariant is always preserved into a constraint on the times at which the configuration parameters change. The method then solves this constraint to obtain the required reconfiguration plan. When this constraint is strengthened with a synthesis constraint, it is ensured that any final configuration that is computed is also reachable. An extension of the method allows parameters to take on multiple intermediate values.

Abstract: A recovery method for ring-based network comprises following steps: when an error occurs at first node, second and third nodes adjacent to the first node transmit a link-down packet respectively; after the first node is repaired, the first, second and third nodes transmit a link-up packet respectively, and each link-up packet includes a priority value of the first, second or third node; the priority values of the first, second and third nodes are compared with each link-up packet to enter the ring port of the first node, the second node or the third node into a forward status or a blocked status; and a forward link or a blocked link is formed among the ring ports of the first, second and third nodes.

Abstract: In one embodiment, a particular field area router (FAR), in a local computer network (e.g., a mesh network) having a plurality of FARs, advertises a common subnet prefix assigned to the local computer network into a global computer network. Each of the plurality of FARs of the local computer network is configured to accept any traffic destined to the local computer network, and a tunnel overlay is built among the plurality of FARs. Upon receiving a packet at the particular FAR destined to a particular device in the local computer network, and in response to the particular FAR not having a host route to the particular device, it forwards the packet on the tunnel overlay to another of the plurality of FARs of the local computer network.

Abstract: A first end-user device comprising one or more modems enabling the first end-user device to communicate with a network system over a first network and with one or more other end-user devices over a second network, the first network comprising a wireless access network, and at least one processor configured to provide a forwarding service to the one or more other end-user devices, the forwarding service for forwarding first traffic between the one or more other end-user devices and the network system, implement a first service policy for assisting in control of the first traffic, implement a second service policy for assisting in control of second traffic associated with access by the first end-user device to a service over the first network, wherein the second service policy differs from the first service policy, and monitor or identify successful use or attempted use of the forwarding service.

Abstract: A method performed by a network device may include assembling a multiprotocol label switching (MPLS) echo request, the echo request including an instruction for a transit node to forward the echo request via a bypass path associated with the transit node, and an instruction for an egress node to send an echo reply indicating that the echo request was received on the bypass path. The method may also include sending the MPLS echo request over a functioning label switched path (LSP).

Abstract: A node device in an information communicating system: determines whether or not the node device is communicable over the IPv4; determines whether or not the node device is communicable over the IPv6; acquires a first routing table that is generated using a first node device communicable over the IPv4 from a predetermined device that is connected to a network if communication is possible over the IPv4; and acquires a second routing table that is generated using a second node device communicable over the IPv6 from the predetermined device that is connected to the network if communication is possible over the IPv6. If the controller determines that communication is possible over the IPv4 and the controller determines that communication is possible over the IPv6, the controller acquires one of the first one of the first routing table and the second routing table according to a priority order.

Abstract: This disclosure relates to a system and method for offloading selected data traffic in logical tunnels to the Internet. The offloading provides another data path for selected data traffic that can relieve the burden on a mobile operator's network, such as the backhaul and core networks. As the proliferation of data rich content and increasingly more capable mobile devices has continued, the amount of data communicated over mobile operator's networks has increased. Upgrading the existing network that was designed for voice calls is not desirable or practical for many mobile operators. This disclosure provides systems and methods for offloading data to the Internet at a router to relieve congestion on the mobile operator's network.

Abstract: A connection oriented communications network has a plurality of nodes including a plurality of edge nodes. The network is arranged to define a primary tunnel connecting a primary one of the edge nodes to another edge node and a secondary tunnel connecting a secondary one of the edge nodes to another edge node. The network is arranged to enable switching of traffic from the primary tunnel to the secondary tunnel in the event of detection of a failure in the primary tunnel.

Abstract: When a first communication device receives a predetermined message from a second communication device via a third line (L3) in a state of transmitting frames to a first line (L1) while performing error-correction coding on the frames, the first communication device switches the line used for transmission from L1 to the second line (L2), then transmits a frame of a post-switching message to L1 . The second communication device receives frames from L1 and L2 and performs error correction, stores the frames, on which error correction has been performed, in first and second buffers (B1, B2), and when determining that it is necessary to perform line switching based on the status of error correction with respect to the frames received from L1, transmits a predetermined message to L3, and when receiving the frame of the post-switching message from L1, starts reading frames from B2 after reading all frames stored in B1.

Abstract: A system, method, and computer program for supporting legacy URIs. A method includes receiving a request for a uniform resource identifier and initializing the request with at least an expiration identifier. The expiration identifier is one of a date, NOW, and NEVER. The method also include determining a redirection type based on a current date. If the current date is less than the expiration identifier or equal to NEVER, then use a meta tag redirect; and if the current date is greater than or equal to said expiration identifier or equal to NOW, then use a status code redirect. The method also includes mapping the URI to a redirect-URI. Corresponding systems and computer-readable instructions are also discussed.

Abstract: The present disclosure provides data sharing through virtual removable volumes. A virtual volume of a SAN (storage area network) is presented to clients as a virtual removable volume. A controlling application controls access of clients connected to the SAN to the virtual removable volume. The controlling application allows only one client at a time to access the virtual removable volume. The controlling application allows a first client to mount the virtual removable volume as a removable volume. The controlling application then causes the first client to unmount the virtual removable volume and allows a second client to mount the virtual removable volume as a removable volume. In this way, the first client and second client are able to share data via the virtual removable volume without causing corruption of data and without requiring a shared file system or physical transfer of removable media.

Abstract: In Low Earth Orbit (LEO) satellite networks data routes for point to point and point to multipoint communication sessions in LEO satellite networks are determined by considering session bandwidth, priority, and the constantly changing terminal-satellite and satellite-satellite connectivity. Multiple routes are computed for a session to facilitate automatic adaptive rerouting by satellite payloads when they encounter network failures or congestion conditions.

Abstract: Embodiments of the invention relate to virtual link aggregation. One embodiment includes forming one or more virtual links using physical links connecting a first networking element, a second networking element and a third networking element. A first trigger status indication is used for blocking network traffic for avoiding traffic loops occurring over the one or more virtual links.

Abstract: Exemplary embodiments provide a technique to improve the system availability of the systems that have multiple links and are connected to a network fabric. In one embodiment, a switch comprises: a memory storing a first logical group which has a first plurality of IP addresses of a first plurality of ports and is assigned to a first ID (identifier), and a second logical group which has a second plurality of IP addresses of a second plurality of ports and is assigned to a second ID; and a controller controlling to cause a logical path of the first logical group to use a first physical path which is different from a second physical path to be used by a logical path of the second logical group, based on the first ID and the second ID.

Abstract: An example method is provided and includes communicating a request packet to a first network element. The request packet is associated with a request for a list of flow parameters. The method also includes receiving a response to the request for the list of flow parameters, and communicating a test packet to initiate fault monitoring. The test packet is communicated to a second network element and the test packet includes at least one of the flow parameters provided by the first network element. The method also includes receiving a plurality of fault monitoring results. The results are limited to reflect multiple paths associated with the first network element.

Abstract: A recovery network may provide communication recovery and backup services to an organization. The organization may comprise an internal network, such as Internet Protocol (IP) network. An alternative communication path communicatively couples communication devices of the organization to a public communication network. A recovery application operates on devices of the organization. The recovery network receives periodic availability indicators from devices within the organization. The recovery network identifies a communication endpoint of the intended recipient of a communication request using the availability indicators.

Abstract: Methods and systems for controlling network traffic in a network are disclosed herein and may include monitoring network traffic characteristics for a plurality of communication channels in a home network, by at least one processor within the home network. The at least one processor may re-route network traffic for at least a portion of the plurality of communication channels in the home network, based on analysis by the at least one processor of at least the monitored network traffic characteristics. Network traffic can be estimated for at least a portion of the plurality of communication channels in the home network by the at least one processor within the home network, based on the monitored network traffic characteristics. The at least one processor may re-route network traffic for a portion of the plurality of communication channels in the home network, based on the estimated network traffic.

Abstract: Systems and methods of selecting a media path for data packets bearing the media of a telephone call to traverse during a voice over Internet protocol telephone call include testing the call quality of multiple potential media paths immediately before a call is setup. The potential media path with the highest call quality is used as the initial media path for the call. If the call quality of the media path currently in use declines below a threshold value during a call, potential alternate media paths are identified and tested for call quality. If one of the alternate media paths has better call quality than the media path presently in use, the call is switched to the alternate media path with the highest call quality.

Abstract: A method, system and server comprise determining, at a server, an appropriate Position Determining Entity (PDE) to forward data to based on a network in which a mobile station is roaming and forwarding the data from the server to the PDE.

Abstract: In one embodiment, a set of tunnels is determined that traverse a particular link connected to an intermediate node in a network. The intermediate node computes, in a coordinated path computation, paths for tunnels of the set of tunnels that do not include the particular link. The coordinated path computation considers each of the tunnels of the set of tunnels. The intermediate node selects one or more tunnels of the set of tunnels for preemption. The one or more tunnels are selected as tunnels that are reroutable by respective head-end nodes of the one or more other tunnels. Notifications are sent to one or more other intermediate nodes that inform the one or more other intermediate nodes of the one or more tunnels selected for preemption.

Abstract: Methods for distributing content in an entertainment system are provided. The entertainment system includes a plurality of clients connected in a bi-directional loop configuration. Each of the plurality of clients has at least one associated video display unit. The method includes deriving a content distribution plan for distributing content files to the plurality of clients based on a theoretical symmetric system where each of the plurality of clients in the symmetric system is configured to store at least a fraction of each of the content files; and applying the derived content distribution plan for distributing content files to an actual entertainment system wherein each of the content files are stored in full in at least one of the plurality of clients of the system to provide an actual content distribution plan for the actual entertainment system. Related entertainment systems and content distribution modules are also provided.

Abstract: Embodiments of the invention a method for policing a packet at line rate. A hierarchical policer receives a policer request comprising packet characteristics and identifying request configuration information. The hierarchical policer retrieves meter states specified by the request configuration information. The hierarchical policer processes packet characteristics through meters to generate a meter result. The hierarchical policer generates a hierarchical policer table lookup address using a plurality of meter types, a plurality of input color controls, one or more of the packet characteristics, the meter results, and a plurality of coupling algorithm identifiers. The hierarchical policer reads a hierarchical meter result from a hierarchical policer result table, containing at least a final output packet attribute that classifies the packet. The hierarchical policer updates one or more of the meter states based on the plurality of meter state results.

Abstract: A data center network system and a packet forwarding method thereof are provided. The data center network system includes a virtual bridge and an address resolution protocol (ARP) server. The virtual bridge intercepts an ARP request having an identification field and a destination IP address field and adds a corresponding virtual data center identification to the identification field of the ARP request and redirecting the ARP request to the ARP server. Additionally, the ARP server queries a corresponding MAC address according to an IP address recorded in the destination IP address field of the ARP request and the corresponding VDCID recorded in the identification field of the ARP request, and transmits the corresponding MAC address in response to the ARP request. Accordingly, the same private IP address can be reused in the data center network system.

Abstract: System, apparatus, and methods for dynamically managing logical path resources are provided. The logical path resources are managed by adding, removing, and establishing logic paths based on specified priority schemes associated with the logical path resources. Information associated with the logical path resources is updated in a logical path resource table.

Abstract: A switch element and a method for routing packets in an IB Multi Level switch and network is provided. The method includes determining if alternate routing is enabled for a packet; determining an alternate route address for the packet, if alternate routing is enabled; and routing the packet using the alternate route address, if the alternate route address is valid. The switch element includes a routing table in a port that determines a base route address; and if alternate routing is enabled for a packet, the port determines an alternate route address for a packet; and routes the packet using the alternate route address.

Abstract: Devices, systems and methods that route a communication link to a proper destination are disclosed. The method may include connecting the communication link to a first destination; requesting a response from the first destination; validating the response from the first destination; and disconnecting the communication link to the first destination if the response from the first destination is not valid. The method may also include connecting the communication link to a second destination; requesting a response from the second destination; and disconnecting the communication link to the second destination if the response from the second destination is not valid. The devices, systems and methods may provide hunt group, call center and conference call features as discussed later herein.

Abstract: A method and system is provided to reduce the time to restore links in a communication system. The method and system employ a preplanned backbone zone to eliminate downtime searches for alternate paths. Efficient use of restoration techniques assures that inter-zone routes are properly allocated. Alternate paths are chosen by calculating shortest paths from a root node to a target node. The shortest paths are placed in a table for lookup whenever a communication failure occurs. Considerations as to cost and length are taken into account in determining the alternative routes.