Abstract: A network processing device includes multiple control processors or applications. One or more of the multiple processors generates an address resolution request. A network interface is adapted to detect a reply to the address resolution request and broadcast the detected address resolution reply to the multiple control processors in the network processing device.

Abstract: A header value or label, referred to herein as a source station identification (SSID), is added to an encapsulated packet header, such as by adding the SSID as a label to the bottom of a stack of MPLS labels. The SSID comprises a unique identifier that identifies the PE that originated the packet. In some embodiments, the IP address of the originating PE may be used as the SSID for that PE. The PE receiving this packet can then associate the source Ethernet MAC address of received TLS traffic, e.g., with the originating PE. Given the SSID of the originating PE, the receiving PE is able to determine which LSP to use to send Ethernet traffic to the station with the learned MAC address.

Abstract: A packet-switched network system comprises a multiplicity of multi-port network units each of which has first and second ports and other ports and transmission links coupling the first and second ports of said unit in a closed ring. The first and second ports and transmission links support duplex transmission of Ethernet data packets. Each unit transmits from said first and second ports packets including selected information enabling on reception of a packet at any of the units a determination of a number of hops from unit to unit around said ring said packet has made. Each unit has a forwarding database and in response to the said selected information controls the transmission of said packets in two directions around said ring, and each unit causes discard of packets which have according to said selected information circumnavigated the ring.

Abstract: A system and method for processing packets of information includes an ingress module. The ingress module receives a plurality of packets of information from a first network. The ingress module determines the type of each of the plurality of packets. A route server module is coupled to the ingress module. The route server module sends a distributed processing request to the ingress module. The ingress module receives the distributed processing request and, responsively, performs a first set of processing operations on selected ones of the plurality of packets. The selected ones of the plurality of packets are of a first type. The ingress module forwards others of the plurality of packets of information to the route server module. Each of the others of the plurality of packets are of a type distinct from the first type.

Abstract: A method for preventing out-of-ordering of frames in a network switch, wherein the method includes the steps of receiving a first portion of a string of packets from a source port on a first port, transferring the first portion of the string of packets to a second port for transmission to a destination, and sending an indicator from the first port to the second port. The method further includes the steps of receiving the indicator at the second port, sending a response indicator from the second port to the first port, and receiving a second portion of the string of packets from the source port on a third port. Additionally, a method for preventing out-of-ordering of frames in network switch, wherein the method includes receiving packets on a first ingress port from a source port, transmitting the packets from the first ingress port to an egress port for transmission to a destination, and determining to switch the receiving of the packets to a second ingress port.

Abstract: A system and method for connecting a call in a tandem architecture comprises a signaling processor for processing call signaling to determine connections for the user communications. A controllable asynchronous transfer mode (ATM) matrix accepts control messages form the signaling processor and accepts user communications from switching systems. In response to the control message, the ATM matrix connects the user communications to the designated connection.

Abstract: A method of broadcasting a packet to the ports belonging to one VLAN of a network, whereas the network has multiple network switches. Each network switch has its own local ports and a local VLAN table. Each local VLAN table stores local port membership of its network switch, and switch membership per VLAN identifier. The local VLAN table is accessed by a VLAN identifier which is stored in the packet, and retrieves the local port membership and switch membership associated with the VLAN identifier. A copy of the packet is provided to each local port and to each switch retrieved from said local VLAN table.

Abstract: A transport scheme is provided based on Internet protocol (IP) and multiprotocol label switching (MPLS) technology for third generation (3G) radio access networks (RAN). Label switched paths are established and managed for interconnecting base stations and radio network controllers. The process incorporates constraint-based routing and Diffserv to provide transport bearers that can support bandwidth provisioning and a variety of QoS requirements in the RAN.

Abstract: A method for disseminating MAC addresses for discovered network devices through a plurality of network switches which cooperate to enable maintaining multiple active paths between such devices. Where a plurality of network switches cooperate through load balancing protocols to enable simultaneous use of multiple paths between, protocols of the present invention permit newly discovered MAC addresses attached to ports of an edge switch to be disseminated through the network switches. When an edge switch detects a device having a previously unknown MAC address, a MAC address information packet is generated and disseminated from the edge switch the other switched of the same load balance domain. The packet is preferably, in effect, broadcast using the pruned broadcast tree constructed and maintained by other protocols related to the present invention. Each intermediate switch on the broadcast tree eventually receives the MAC address information packet from a neighboring switch in the load balance domain.

Abstract: A distributed network access system in accordance with the present invention includes at least an external processor and a programmable access device. The programmable access device has a message interface coupled to the external processor and first and second network interfaces through which packets are communicated with a network. The programmable access device includes a packet header filter and a forwarding table that is utilized to route packets communicated between the first and second network interfaces. In response to receipt of a series of packets, the packet header filter in the programmable access device identifies messages in the series of messages upon which policy-based services are to be implemented and passes identified messages via the message interface to the external processor for processing. In response to receipt of a message, the external processor invokes service control on the message and may also invoke policy control on the message.

Abstract: A method for communicating between a first device and a second device, wherein the communication occurs across a fabric and the first device is coupled to the fabric by a first gateway and the second device is coupled to the fabric by a second gateway. The method includes adjusting, at the first gateway, upon receipt of a first device readiness signal a first device readiness indicator to indicate an increase in a number of frames the first device is ready to accept, and sending, from the first gateway to the second gateway, a first gateway readiness signal, the first gateway readiness signal indicative of an increase in a number of frames the first gateway is ready to accept.

Abstract: A computer telephony system includes a multi-platform architecture that provides a layer of abstraction between application software and hardware associated with a platform. According to this architecture, service modules residing on different platforms access computer telephony resources to facilitate performance of a variety of computer telephony services. Although local access to such resources is governed by diverse, platform-dependent protocols, the service modules communicate with one another according to a common, platform-independent protocol. In this manner, cross-platform communication is abstracted to isolate system software and firmware from hardware-based platform dependencies. Instead of threaded drivers creating a persistent, dedicated link with resources, communication can be accomplished via a common, platform-independent message packet protocol.

Abstract: A method for fast protection in a fault-tolerant network includes coupling an edge switch in a network to one or more access switches via at least first and second redundant links, respectively connected to first and second ports of the edge switch. The first port is placed in an active state, while the second port is placed in a blocking state, so that communication traffic is conveyed over the first link, and each of the switches builds a respective database for use in forwarding the traffic. Responsive to a failure associated with the first link, the second port is placed in the active state and the first port is placed in the blocking state. Dummy traffic is then sent from the edge switch over the second link to the one or more access switches, so as to cause each of the one or more access switches to modify its respective database responsive to the second port being in the active state.

Abstract: A technique for an improved active queue management scheme which dynamically changes its threshold settings as the number of connections (and system load) changes is disclosed. Using this technique, network devices can effectively control packet losses and TCP timeouts while maintaining high link utilization. The technique also allows a network to support a larger number of connections during congestion periods.

Abstract: A method and apparatus for communicating fixed-length data packets through an intermediate computer network. The method comprises receiving a data packet characterized by a fixed-length packet format, and constructing a remnant packet characterized by the fixed-length packet format, which includes inserting at least a portion of the data packet routing information in the data field of the remnant packet. The method also comprises communicating the remnant packet, receiving the remnant packet and constructing a reconstructed data packet, which includes Inserting data packet routing information obtained from the remnant packet in the address field of the reconstructed packet. The apparatus comprises a communication network node comprising a receiver, transmitter, computer memory and processor for performing the foregoing method steps.

Abstract: A system and method connect a call in a broadband system using the asynchronous transfer mode protocol for switching. Calls are connected over a SONET ring that has SONET multiplexers coupled by SONET paths. The SONET multiplexers are adapted to add calls to, and drop calls from, the SONET ring. An ATM cross connect system that has ATM cross connect devices is coupled to the SONET ring. The ATM cross connect devices provide provisioned ATM connections over the SONET ring. ATM interworking units are coupled to the ATM cross connect system. The ATM interworking units interwork calls with selected ATM connections in response to control messages. The selected ATM connections are provisioned between the ATM interworking units by the ATM cross connect system over the SONET ring. A signaling processor system receives call signaling for the calls, processes the call signaling to select the ATM connections for the calls, and sends the control messages to the selected ATM interworking units.

Abstract: In an ATM satellite communication system, congestion parameters for the downlink from the satellite are measured in the satellite and are broadcast to the downlink terminals or to the downlink and uplink terminals linked by virtual channels extending through the satellite. At a downlink terminal or uplink terminal, the parameters broadcast from the satellite are used to calculate an explicit rate for a virtual channel in the downlink. The explicit rate calculated at the terminal is used by the source for the virtual channel to determine the rate of transmission of Available Bit Rate cells on the virtual channel.

Abstract: A storage structure includes a plurality of sequentially arranged positions, each position for holding one order at a time. One of the positions is an end position from which an order is to be taken up for provisioning. Each order in a position moves to the next sequential position toward the end position, as the next sequential position becomes empty and available. The positions are organized into a first section and a second section. The first section is distal from the end position and includes at least one position. The first section receives orders from a first order delivery system into a receiving position. The second section is proximate to the end position and includes at least one position. The second section receives orders from a second order delivery system into a receiving position.

Abstract: A wide area communication network includes at least two hub sites which are interconnected by a communication backbone Each hub site provides wireless coverage in at least one sector. At least two remote sites reside in each sectors and are coupled to a corresponding hub site via a point to multi point broadband wireless system. The network preferably includes at least one service node which is accessible to the remote sites via the hub sites and backbone.

Abstract: Using alternate routes for fail-over in a communication network involves maintaining a preferred route and an alternate route in a routing table and routing protocol messages according to the alternate route when the preferred route is unavailable. A node obtains multiple routes for a destination, prioritizes the routes, and installs multiple routes in the routing table, including at least the preferred route and the alternate route. When the node receives a protocol message, the node searches the routing table for a highest priority route that is available for routing the protocol message, and routes the protocol message according to the highest priority route that is available for routing the protocol message. When a route becomes unavailable, the node updates the routing table to indicate that the route is unavailable, and may compute new routes and/or re-prioritize existing routes.

Abstract: A network switch for switching packets from a source to a destination includes a source port for receiving an incoming packet from a source, a destination port which contains a path to a destination for the packet, and a filter unit for constructing and applying a filter to selected fields of the incoming packet. The filter unit further includes filtering logic for selecting desired fields of the incoming packet and copying selected field information therefrom. The filtering logic also constructs a field value based upon the selected fields, and applies a plurality stored field masks on the field value. The switch additionally includes a rules table which contains a plurality of rules therein. The filtering logic is configured to perform lookups of the rules table in order to determine actions which must be taken based upon the result of a comparison between the field value and the stored filter masks and the rules table lookup.

Abstract: A system and method is directed to updating a route table in a distributed routing platform, thereby enabling multiple routing protocols to be executed on different routing modules. A slave route distributor on one routing module is configured to receive a route from a local route table and flow manager. The slave route distributor communicates the route to a master route distributor on another routing module by way of an inter process communications protocol. The master route distributor provides the route to its local route table and flow manager, where a determination is made whether the route is a best route. If the route is a best route, the master route distributor updates its external routing table. The master route distributor also distributes the route to another slave route distributor on yet another routing module, where the route enables an update to a remote routing protocol, and routing table.

Abstract: A call manager includes a device process that controls a first device and that receives a call request from the first device. The call request includes a telephone number associated with a second device that is controlled by a second call manager. The call manager also includes a digit analysis module that determines device location information associated with the telephone number included in the call request. Furthermore, the call manager includes a call control module operable to receive the device location information from the digit analysis module and to communicate the call request to the second call manager identified by the device location information.

Abstract: In a distributed switch fabric network (300) having a first node (302) having a first node transceiver port (305) and a second node (304) having a second node transceiver port (340), link level flow control (370) operating between the first node transceiver port and the second node transceiver port to in response to a congestion condition (321) in the second node transceiver port, wherein the link level flow control suspends transmission of one of a plurality of priority levels of packets (312) on a channel from the first node transceiver port to the second node transceiver port. The one of the plurality of priority levels of packets accumulates in one of a plurality of a transmit buffers (362) of the first transceiver port, where the one of the plurality of transmit buffers corresponds to the one of the plurality of priority levels of packets.

Abstract: According to the invention, methods and apparatus are disclosed for selecting one of multiple of paths between two points over which to route a data item based on the destination of the data item and the traffic between the two points over the multiple paths. A switching system can use the disclosed methods and apparatus to more efficiently distribute data packets among switching fabrics than currently accomplished by known techniques. In one implementation, distribution cycles have been established for sending data between two points, where each path between the endpoints is used a predetermined number of times (e.g., one, two) within each cycle. To economize the amount of traffic data collected, the multiple paths can be partitioned into subsets for which traffic data is maintained only for the current subset. Additionally, the distribution of traffic between the two points can be further partitioned into traffic of a particular type or priority between the two points.

Abstract: The present invention is directed to a host interface bypass on a fabric based array controller. An apparatus of the present invention may include an external electronic device suitable for performing a function, a controller and a fabric connection. The controller includes at least one internal module, the internal module providing a controller function. The fabric connection communicatively connects the external device to the controller, wherein the module of the controller is directly accessible by the external electronic device.

Abstract: An apparatus of the present invention is an apparatus including a communication section for communicating with another apparatus. The apparatus includes: a registration detection section for detecting grouping registration information which is provided to each of a plurality of apparatuses to be grouped and registered; a storage section for storing group information which indicates that the apparatus and the other apparatus are in the same group; and a control section for controlling the communication section, the registration detection section and the storage section.

Abstract: A method of packet switching the packets in a data packet communication environment having a plurality of digital packet transmission stations interconnectable in paths. The steps include causing a first digital packet transmission of a smart data packet at a first end to send one or more smart data packets having a learning algorithm therein for learning a path to a second digital packet transmission station at a second end and then causing an acknowledgement packet to be sent from the second end having the learning path of the smart data packet from the first end to the second end in a reverse path direction to the first end. Then waiting at the first digital packet transmission station for the acknowledgement packet before sending a dumb data packet on the learned path received at the first end from the acknowledgement packet whereby a cognitive packet network is formed by packet switching.

Abstract: An apparatus and method for workload balancing along multiple communication paths to a plurality of devices. The apparatus includes a controller that accumulates path usage information and a path balancing device that makes use of the accumulated path usage information to perform a path balancing operation. The path balancing method involves the path balancing device calculating the total expected connect time for all I/O messages issued to each of a plurality of peripheral devices during a predefined sampling period. These totals are then added for each communication path for the sampling period to obtain path totals. The path totals are then compared to see if a difference between the highest used path and the lowest used path is greater than a threshold amount. If the difference is higher than the threshold amount, the peripheral device having a total expected connect time that is closest to a target value is moved from the highest used path to the lowest used path.

Abstract: In a telecommunications network environment including non-participating elements and participating elements, a method for providing a telecommunications service between a first peer element connected to the telecommunications network environment and a second peer element connected to the telecommunications network. At a first peer element, an indication of the type of telecommunications service to be provided between the first peer element and the second peer element is received. A telecommunications service template in association with the indicated telecommunications service is determined, the telecommunications service template including instructions for configuring the non-participating elements of the telecommunications network environment to provide the indicated telecommunications service and instructions for configuring the participating elements of the telecommunications network environment.

Abstract: A distributed system structure for a large-way, symmetric multiprocessor system using a bus-based cache-coherence protocol is provided. The distributed system structure contains an address switch, multiple memory subsystems, and multiple master devices, either processors, I/O agents, or coherent memory adapters, organized into a set of nodes supported by a node controller. Each of the processors may have multiple caches. The address switch connects to each of the node controllers and to each of the memory subsystems, and each of the memory subsystems connects to the address switch and to each of the node controllers. The node controller receives commands from a master device and queues commands received from a master device. The buses between the master devices, the node controllers, the address switch, and the memory subsystems are operable using a variety of bus protocols.

Abstract: A system for multicasting in a high-speed switching environment includes a data memory logically divided into a plurality of blocks, a plurality of output ports, and a central agent. The central agent can determine whether all one or more output ports for a packet stored in one or more blocks have read the packet. Each block of the packet can be added to a pool of available blocks when a last one of the one or more output ports for the packet has read from the block.

Abstract: A system of switch modules comprises input demultiplexers connected to ports on each of the modules and output multiplexers connected to each of the modules. Each module has output and input interfaces for mesh links and at least one output interface is looped back to an input interface on the same module. The arrangement reduces module-to-module traffic and corresponding increases the transmit bandwidth of a module.

Abstract: The invention relates to a circuit arrangement for data stream distribution with conflict resolution, whereby data streams are transmitted bi-directionally, such that first data stream connection units (104a-104n) and second data stream connection units (105a-105m) serve as both input and output connections. A distribution unit (100), essentially comprises a matrix switching unit (101), first intermediate buffer units (106a-106n) and second intermediate buffer units (107a-107m). Information is firstly evaluated in the cell head, which, together with information on the availability of intermediate buffer units, determine when a present data stream cell may be transmitted to a relevant output connection unit.

Abstract: A client line accommodation unit for accommodating a variety of transmission data on a client-by-client basis comprises a path switch for performing a switching operation. A plurality of the client line accommodation units are interconnected in a mesh configuration through the path switches included therein to realize a small-scale path crossing connect device. On the other hand, a plurality of the client line accommodation units may be interconnected in a fixed manner through the path switches included therein to realize a service multiplexer device. In addition, a large-scale path switch may be added for expanding the switching capacity to realize a large-scale path crossing connect device.

Abstract: A distributed Link-State Routing Protocol (LSRP) system in a packet switch having external communication ports has a first card executing Update process of the LSRP, making database updates, a second card executing Decision process(Shortest Path First (SPF)) of the LSRP, and a communication fabric coupling the cards with each other and the external ports. The LSRP may be an IS—IS system. In some embodiments there are additional cards involved, and the distribution of Link-State functions is over a set of multiple cards. Also in some embodiments there is a Location Service (LS) controller monitoring and configuring cards in the system.

Abstract: In a stack of multi-port network communication units each unit has a forwarding database, the units are connected by way of a cascade, and at least some of the units are connected to links constituting a trunk. When a unicast data packet is received at a first of said units and the unicast data packet has a destination address which is not the subject of an entry in the forwarding database of the first unit, the unicast data packet is sent by way of the cascade to the other units in the stack, accompanied by a flag. When a second unit has in its forwarding database an entry, associating the destination address with forwarding data, it sends a management packet indicating said destination address and the identity of said second unit, so that the database of the first unit can be immediately updated.

Abstract: A system and method for ensuring security in a voice trunking over ATM (VTOA) environment is provided. A telecommunications network is provided that carries control traffic and bearer traffic via ATM communications channels and TDM communications channels. The telecommunications network includes at least one closed user group consisting of multiple closed user group members. The closed user group members include trunk interworking function (T-IWF) devices configured to receive end office voice trunks from TDM channels and convert the trunks to ATM cell streams and to receive ATM cell streams and convert the ATM cell streams to end office voice trunks; and at least one centralized control and signaling interworking function (CS-IWF) device. The CS-IWF device performs call control functions and interfaces narrowband and broadband signaling for call processing and control within the ATM switching network. The closed user group members also includes a VTOA switch management system (SMS).

Abstract: A wide area communication network includes at least two hub sites which are interconnected by a communication backbone Each hub site provides millimeter microwave wireless coverage in at least one sector. At least two remote sites reside in each sector and are coupled to a corresponding hub site via a point to multi point broadband millimeter microwave wireless system. The network preferably includes at least one service node which is accessible to the remote sites via the hub sites and backbone.

Abstract: A distributed telecommunications switching subsystem (100) receives and distributes data packets passed between a plurality of switching subsystems or channel banks (102, 104, 106) and a data packet switch (110). Each channel bank (102) has a stored list of addresses. When a channel bank (102) receives a data packet, it compares the address of the data packet to its stored list of addresses, and transmits the data packet to another channel bank (104) if the address of the data packet does not correspond to any of the addresses in its stored list of addresses. The data packet is passed on until it reaches a channel bank (106) with a matching address or else it is appropriately handled by a last channel bank (106) in the chain. If the address of data packet matches an address in its stored list of addresses, the channel bank (102) passes the data packet through a subscriber interface card (120) to a customer premises equipment unit (108) corresponding to the address of the data packet.

Abstract: A network system (10). The system comprises a network (WAN1, LAN1, LAN2) having an architectural model comprising a plurality of layers. The system also comprises a centralized manager node (CM1), coupled to the network. The system also comprises a plurality of routers (ERx) coupled to the network for communicating packets along the network and coupled to communicate with the centralized manager node. The centralized manager is programmed to perform the step (28) of communicating mapping information to each of the plurality of routers, and the mapping information comprises a correspondence of a behavior on a first of the plurality of layers with a behavior on a second of the plurality of layers.

Abstract: A network processing device intelligently interleaves packets for read and write access requests in a multibank memory. The system intelligently writes packets into the different memory banks so that the same memory bank is not used for back-to-back packet reads. The last memory bank write is determined for each output queue. This write information is used in combination with look ahead packet read information for a group of packets from the next output queue scheduled to read packets from memory. The scheduler uses all this information to avoid any back-to-back packet read, write, or read/write accesses to the same memory bank. This intelligent packet interleaving scheme preserves memory bus bandwidth normally wasted accessing the same memory banks.

Abstract: The present invention provides an Ethernet switching apparatus using frame multiplexing and demultiplexing. The Ethernet switching apparatus has a plurality of frame demultiplexers, a plurality of frame multiplexers and a switch fabric chip set. The frame demultiplexers convert at least one 10 gigabits Ethernet frame into a plurality of gigabit Ethernet frames. The frame multiplexers convert a plurality of gigabit Ethernet frames into at least one 10 gigabits Ethernet frame. The switch fabric chip set is provided with input and output interfaces using the GMII, and is connected to the frame demultiplexers and the frame multiplexers in the GMII format. The switch fabric chip set outputs frames through an arbitrary usable one of a plurality of GMII ports connected to a corresponding frame multiplexer if the frames are transmitted to the corresponding frame multiplexer.

Abstract: A network managing method which divides a network to be managed into a plurality of virtual closed area networks, and defines management information on the virtual closed area networks separately in a plurality of logical hierarchies. A virtual LAN/network space defines a connection state among closed area networks, a closed area space defines attribute information on nodes within a closed area network, and a virtual service defines logical arrangement information on nodes in the overall network. The management information is distributively stored in each node and utilized for MAC control. When the configuration of the network is changed due to movements of nodes, an administrator inputs the contents of the change from the manager of each layer, so that the manager communicates with a node containing corresponding management information to instruct the node to update management information.

Abstract: In order to provide price information to customers quickly a fast reflector switch is used. This helps to ensure that price information provided to customers is as up-to-date as possible. To determine a price for use of a particular route in a communications network, the available resources at each node in that route are assessed. The most congested node in that route is selected and a price determined on the basis of the available capacity at that node. This price is then delivered to the customer via the fast reflector switch. In another example, the average amount of available resources at each node in the route is determined over a specified time period. The standard deviation of the resource level values at each node over the specified time period is also determined. A price is then set on the basis of the sum of the average amounts and the sum of the standard deviations. In this way a price which takes into account recent variation in traffic levels as well as average traffic levels is provided.

Abstract: The present invention is a shared buffer architecture that dynamically allocates buffer size to each of multiple sources depending on buffer pool utilization, estimated per-connection offered load, and the total number of connection established within a given class of service. When the buffer pool is almost empty, each source is allocated a large buffer space, proportional to its estimated offered load. When the buffer pool is more full each source is allocated a reduced buffer space, while maintaining the proportional weighting relationship. The invention keeps track of the amount of input per source and dynamically allocates a proportionate amount of buffer space in the buffer memory for that source. The dynamic allocation is made as a function of the fullness of the memory allocation for all sources. Additionally, thresholds are modulated dynamically as the number of established connections within a given class modulates, providing a predictive aspect to the system, with respect to congestion control.

Abstract: A multi-line telephony system and method deliver multiple concurrent telephone conversations to a customer premise via a single traditional twisted-pair communications connection, and support telephone services via a traditional dial-up connection. Improved packet-based communications are performed using the multi-line telephony system and method with better transmission characteristics, such as transmission speed, over traditional twisted-pair wire connections to provide H.

Abstract: A method for distributing logging and tracing information in a network node is disclosed. In one embodiment, log messages generated locally on the line cards are collected by Secondary Log Managers residing on the line cards. The Secondary Log Managers process the collected messages and transfers at least part of them to a Primary Log Manager residing at the control module. Then, the Primary Log Manager can output the logging and tracing messages to a system monitor or to other output devices, such as a Command Line Interface (CLI) shell or a file.

Abstract: A network of switches with a distributed name server configuration and caching of remote node device information is disclosed. The network preferably comprises a first switch coupled to a second switch. Each of the switches directly couple to respective node devices. The first switch maintains a name server database about its local node devices, as does the second switch. The second switch further maintains a information cache about remote node devices. The name server preferably notifies other switches of changes to the database, and the cache manager preferably uses the notifications from other switches to maintain the cache. The name server accesses the cache to respond to queries about remote node devices. The cache manager may also aggregate notification messages from other switches when notifying local devices of state changes. Traffic overhead and peak traffic loads may advantageously be reduced.

Abstract: A router device and a label switched path control method capable of reducing the number of label switched paths to be set up by using an upstream initiated procedure in which the label allocation starts from an ingress router are disclosed. In the router device, a router identification information of a target router to be set as an egress router if possible is stored in an egress router list at a time of setting up a label switched path from the router device as an ingress router, and a control to set up the label switched path to the target router stored in the egress router list is carried out.