Abstract: A switching device includes an input stage switch group 1-1 including a plurality of input lines, an output stage switch group 1-3 including a plurality of output lines, an intermediate stage switch group 1-2 arranged between the input stage switch group and the output stage switch group, and a scheduler 1-22 deciding a signal path of each of intermediate stage switches 1-21 in the intermediate stage switch group based on information input to the respective input lines. The intermediate stage switch group is divided into a plurality of groups, a plurality of the schedulers is arranged in a distributed fashion to correspond to the plurality of groups, respectively and the schedulers operate independently of one another.

Abstract: A detecting unit detects a connection of an external device to a connection port and stores the connection in a bridge state storage unit. This setting is autonomously completed by a device before an initial configuration is started by a host. A data transfer unit receives initial configuration data of a link-connection bridge from the host. Data is transferred to the linked-uplink-connection bridge with reference to the bridge state storage unit, data to a bridge which is not linked up is wasted, or an Unsupported Request is returned to the host to represent the absence of the link-connection bridge.

Abstract: A packet communication device autonomously selects an appropriate operation mode according to a connection environment to an external device before a service of the device is started. When the device is connected to the external buses, connection interface units notify an external device discrimination unit of connection of the device. The external device discrimination unit issues a polling packet to the connected device, discriminates the connected external device on the basis of the response packet, and notifies an operation mode switching unit. The operation mode switching unit selects an operation mode conforming to a connection environment of the packet communication device to the external device and switches the operation mode of the device to the mode.

Abstract: Provided in the EoE technique are the node, the network, the correspondence relationship generating method and the frame transfer program to avoid traffic concentration on a specific link to improve throughput of the network as a whole by realizing optimum path transfer. The frame switching unit includes the frame analysis unit for analyzing an input frame kind and the like, the table search unit for obtaining frame rewriting information and output port information, the forwarding table storage unit for managing an output port of a frame, the MAC learning unit for executing MAC address learning, the EoE-MAC learning unit for learning a relationship between a MAC address and an EoE-MAC address, the STP control unit for executing processing of a spanning tree, and the like.

Abstract: A node that configures a spanning tree over a network to which a plurality of nodes are connected generates a tree after a cost change using another LAN while continuing to operate the tree that existed before the change, and switches the tree that is used for forwarding after the new tree has been stable.

Abstract: A TCP 2003 is terminated in an intermediate driver 2006 within a gateway device 20, a TCP 3003 is terminated in an intermediate driver 3006 within a gateway device 30, and a frame is transferred between the intermediate drivers with a method not causing a congestion control such as a UDP. Besides, an SSL session is constructed between an SSL 2002 and an SSL 3002, and upon completing construction of the session, a public key and a secret key are sent by means of an Ethernet frame from a processing speed acceleration engine control to a processing speed acceleration engine. Thus, the gateway device transfers the frame not through a CPU but by employing the processing speed acceleration engine within an NIC in later communication between a terminal 21 and a server 31.

Abstract: A local-memory side data transfer unit increments the number of addresses, reads out data from a local memory, and stores the data into a cache memory of a remote-memory side data transfer unit. For preventing data mismatching with the local memory from being stored into the cache memory, a cache clearing operation is executed in units of an elapse of a round trip time period for data transfer between the local memory and the remote memory. Alternatively, the cache clearing operation is executed upon receipt of a signal notifying data transfer of data stored at a specified address.

Abstract: A VPN connection method and a communication system are provided, each which can omit the setting of a firewall and the installation of a relay server and can establish communications from the outside of a firewall to the inside thereof. The internal network 2 is connected to the external network 1 via the firewall 13. The internal network 2 enables communications by an e-mail from the external network 1 (outside the firewall) to the mail server 21 in the internal network 2 (inside the firewall) or communications by telephone or radio, which is not via the firewall 3. The feature of the firewall 3 is utilized that access from the outside to the inside of the firewall through VPN connection is very difficult but the access in the reverse stream can be simply performed. Using the mail server, telephone line or radio line, the internal network 2 receives an e-mail, which requires for VPN connection from the external network 1, or control information through the telephone line.

Abstract: An I/O equipment sharing system includes CPUs, a plurality of route complexes coupled to the CPUs, upstream PCI Express-bridges coupled to the route complexes, downstream PCI Express-bridges coupled to the upstream PCI Express-bridges through a network, and I/O equipment coupled to the downstream PCI Express-bridges. In the above configuration, the I/O equipment are shared between the CPUs using the identifiers of the network (for example, Ethernet VLAN IDs), the identifiers are set so that they do not overlap between the respective CPUs and necessary I/O equipment is set to a set identifier. Further, an identifier is set to a plurality of the same I/O equipment required by the respective CPUs.

Abstract: A virtual PCI Express device 1600 indicates the presence of a pseudo I/O device in a PCI Express initial configuration cycle to reserve a resource space for a device anticipated to be installed in the future, and when an I/O device 1400 is inserted into an unoccupied slot 1605, a virtual PCI Express device control logic 1602 notifies a downstream PCI-PCI bridge 1504 via a hot-plugging control line 1601, and the downstream PCI-PCI bridge 1504 generates an interrupt to a CPU 1100 to notify it of insertion of the I/O device 1400 in conformance with the procedure for hot plugging defined by the PCI-SIG Standards, and configuration software 1000 invoked configures the inserted I/O device 1400.

Abstract: A network system in which a network adopting a node redundancy protocol and a network adopting an STP protocol as other protocol for managing a state of a port coexist, which is configured to manage, by the STP protocol as other protocol, a state of a port which belongs to a master node 10 and a backup node 20 forming the network adopting the STP protocol and is under the management of the node redundancy protocol and also under the management of the STP protocol, and in which the master node 10 or the backup node 20 transmits a Hello message as a control frame for monitoring a node and a link to all or a part of nodes connected to the port under the management of the node redundancy protocol, as well as transmitting a Flush message as a control frame for rewriting a forwarding database to all or a part of nodes connected to the port under the management of the node redundancy protocol at the time of switching to a master mode.

Abstract: A PCI Express switch which connects a plurality of peripheral devices to an arbitrary one of a plurality of CPUs through an Ethernet is constituted by a plurality of upstream and downstream PCI Express-network bridges, an Ethernet switch, and a system manager. Each of the upstream and downstream PCI Express-network bridges includes a PCI Express adapter which terminates a link of a PCI Express bus, a network adapter which terminates a link to the Ethernet switch, and a control unit which encapsulates a TLP in a frame, the destination of which is a MAC address of a bridge to which the destination is connected to transmit and receive the frame. Because the switch according to the present invention comprising a plurality of upstream PCI Express-network bridges and a plurality of downstream PCI Express-network bridges connected to the plurality of upstream PCI Express network bridges through a network is equivalent to a conventional PCI Express switch, it is needless to change a conventional PCI software.

Abstract: A base node (100) and a base node (101) transmit a keep alive frame broadcast by a relay node forming a communication medium (106) and a communication medium (107) from a port 1 and a port 2, monitor an arrival state of the keep alive frame at each port, and in normal operation, assume the two communication media connected to the port 1 and the port 2 as one node to expand a communication band and at failure detection, continue communication by using only a communication medium connected to a port at which no failure is detected.

Abstract: A network system is comprised of a learning management program in a CPU to send and receive a learning frame, a frame transfer unit which transfers a learning frame, and a learning frame transmission management unit which judges whether learning has completed or not.

Abstract: A node of a spanning tree system operating on a network connecting a plurality of nodes, comprises two transfer units which determines an output destination port, based on the destination MAC address of an input frame, two tree managers which configures a spanning tree according to a spanning tree protocol, and a virtual port of connecting the tree manager and the transfer unit.

Abstract: A node that configures a spanning tree over a network to which a plurality of nodes are connected generates a tree after a cost change using another LAN while continuing to operate the tree that existed before the change, and switches the tree that is used for forwarding after the new tree has been stable.

Abstract: In frame transfer in a network for transferring an Ethernet frame sent from a source on the network to a predetermined destination, to an applied Ethernet frame, an expansion tag containing information about forwarding to an egress edge node to a host as a destination is added to make an expansion frame, and each node on the network relays the data frame based on the forwarding information of the added expansion tag to transfer the frame to the egress edge node.

Abstract: A node to relay the Ethernet frame provided with means to insert, in the relay process of the frame, two or more VLAN tags into the frame at a time and to remove the inserted VLAN tags wherein a TTL area to show the frame survival time is provided in the VLAN tag to be inserted to the frame so that whether the survival time has been elapsed or not is checked by the value in the TTL area and the frame after elapse of the survival time is discarded without being relayed.