Abstract: A data communication apparatus to be coupled to a first network and a Multiprotocol Label Switching (MPLS) network, includes a receiving unit which receives a data including header information indicating a destination and first header information used to identify a first Virtual Private Network (VPN) in the first network. The apparatus also includes a transmitter which transmits data having added thereto a MPLS header information used to identify one of the plurality of second VPNs in the MPLS network, the MPLS header information corresponding to both the header information indicating the destination and the first header information used to identify the first VPN in the first network included in the received data.

Abstract: A label switching type packet forwarding apparatus having a routing information table in which a forwarding type of a reception packet, output port identification information, and output routing information of a specific layer in the OSI reference model determined by the forwarding type are defined in correspondence with routing information which is found upon reception of a packet, for converting a header of a reception packet in accordance with the packet forwarding type and the output routing information obtained by a table search.

Abstract: A method serves to compose a VPN (Virtual Private Network) over a plurality of networks, each of which is managed by a different Internet Service Provider (ISP). When a packet with a first capsule header used for composing a VPN in a first ISP network is transmitted to a second ISP network, a route for outputting the packet to the second ISP network is determined based on the information both in the capsule header and in the IP header. In addition, a second capsule header used for composing a VPN in the second ISP network is determined based on the above information.

Abstract: Bandwidth control over users accommodated under ONU in PON is achieved. BAS sets user bandwidth information obtained during user authorization in OLT. The OLT achieves bandwidth control on a user basis, using bandwidth information set from the BAS. The present invention enables bandwidth control over users under the ONUs.

Abstract: A method serves to compose a VPN (Virtual Private Network) over a plurality of networks, each of which is managed by a different Internet Service Provider (ISP). When a packet with a first capsule header used for composing a VPN in a first ISP network is transmitted to a second ISP network, a route for outputting the packet to the second ISP network is determined based on the information both in the capsule header and in the IP header. In addition, a second capsule header used for composing a VPN in the second ISP network is determined based on the above information.

Abstract: An input interface segments a variable length packet into plurality of fixed length cells and generates an internal switching information based on the header information of the variable length packet. The input interface transmits the information to a switch and, after that, transmits the cells as the following cells of the information to the switch. The switch performs switching processing to the succeeding cells based on the information. Therefore, the information is not added to the cells. When an input interface starts to transmit cells generated from a packet to its destination output interface through the switch, the switch is reserved until all the cells arrive at the output interfaces.

Abstract: Bandwidth control over users accommodated under ONU in PON is achieved. BAS sets user bandwidth information obtained during user authorization in OLT. The OLT achieves bandwidth control on a user basis, using bandwidth information set from the BAS. The present invention enables bandwidth control over users under the ONUs.

Abstract: Provided is an optical access system comprising: an optical line terminal connected to another network; a plurality of optical network units, each connected to a user terminal; and at least one of an optical switching unit and an optical splitter, which is installed between the optical line terminal and the plurality of optical network units. The optical line terminal allocates a length of time to a discovery phase for detecting the plurality of optical network units, and a length of time to data transmission phases for transferring data from the plurality of optical network units; and changes a ratio of the length of time of the discovery phase to the length of time of the data transmission phases so that the length of time of the discovery phase is shortened in the case where a number of the optical network units that are registered in the optical line terminal increase.

Abstract: On performing load balancing in a network device, there will be provided an apparatus of transmitting packets which implements uniform allocation processing in conformity with the traffic conditions. A packet transfer apparatus is provided with a statistics information collecting processor as a functional processor independent of the packet transfer processing. The line card transfers header information of packets to be transmitted and received to the statistics information collecting processor. The statistics information collecting processor collects statistics information in accordance with header information of transmitted and received packets transferred from the line card. On the basis of the statistics information collected by the statistics information collecting processor, the setting of the search table to be provided for the line card will be renewed.

Abstract: Provided is an optical access system, including: an optical line terminal, a plurality of optical network units and an optical switching unit. The optical line terminal sends to the optical switching unit a control frame including a switching time when the optical switching unit is to make a switch from one of the optical communication paths between the optical line terminal and the plurality of optical network units to another, and an identifier of an optical communication path to which the switch is made in order to switch the optical communication paths between the optical line terminal and the plurality of optical network units. The optical switching unit switches the optical communication paths between the optical line terminal and the plurality of optical network units based on the switching time and the identifier of the optical communication path after switching which are included in the control frame.

Abstract: A gateway for interconnecting different networks includes a network access means for interconnecting a first network that provides a wireless access function to a mobile station with a second network that provides a network access function to the mobile station. The gateway further includes a first tunnel establishment means for establishing, in the first network, a first tunnel between the gateway and a base station accessing one or more mobile stations via wireless communications, for transmission of different packets to the respective mobile stations. The gateway further includes a second tunnel establishment means for establishing a second tunnel between the gateway and the second network, for packet transmission, a tunnel-mobile station connecting means for connecting the first tunnel with the mobile station, and a tunnel-to-tunnel interworking means for interworking the second tunnel with the first tunnel.

Abstract: A label switching type packet forwarding apparatus having a routing information table in which a forwarding type of a reception packet, output port identification information, and output routing information of a specific layer in the OSI reference model determined by the forwarding type are defined in correspondence with routing information which is found upon reception of a packet, for converting a header of a reception packet in accordance with the packet forwarding type and the output routing information obtained by a table search.

Abstract: In a device that interworks a VLAN network and an MPLS network, a VLAN ID is associated with an MPLS label. In a device that performs interworking from a VLAN network to an MPLS network, an output MPLS label is determined from a pair of a VLAN ID and the information in the layer 3 or layer 4 header of a packet. The output MPLS label is assigned an independent value for each VLAN. In a device that performs interworking from the MPLS network to another VLAN network, the input MPLS label is associated with a VLAN ID.

Abstract: A label switching type packet forwarding apparatus having a routing information table in which a forwarding type of a reception packet, output port identification information, and output routing information of a specific layer in the OSI reference model determined by the forwarding type are defined in correspondence with routing information which is found upon reception of a packet, for converting a header of a reception packet in accordance with the packet forwarding type and the output routing information obtained by a table search.

Abstract: In an IP packet communication apparatus, an operation and maintenance function capable of monitoring a transmission path is provided to a layer used to process a packet, which corresponds to an upper layer of an optical network. As one method for applying the operation and maintenance function to the packet layer, in the case of IP over PPP over WDM, an operation/maintenance frame is defined to a PPP frame so as to realize the operation/maintenance function of a PPP connection. In the case that a plurality of connections are multiplexed on the same transmission path, a maintenance frame is conducted in order to operate/manage these connections by being grouped, so that a fault occurring in the optical network is monitored. As another method for applying the operation and maintenance function to the packet layer, an operation/maintenance frame is defined to an IP packet so as to realize an operation and maintenance function of an IP flow.

Abstract: To prevent a packet loss during hand over, provided is a network system including: a gateway coupled with a wired network; and at least two base stations coupled with the gateway over the wired network and providing a wireless access method, in which the gateway is configured to: calculate, for each of the at least two base stations, a delay in information transmission between the gateway and each of the at least two base stations; choose a maximum delay from among the calculated delays of each of the at least two base stations; calculate, as a delay difference of each of the at least two base stations, a difference between the chosen maximum delay and the delay of each of the at least two base stations; and notify each of the at least two base stations of the calculated delay difference of each of the at least two base stations.

Abstract: Bandwidth control over users accommodated under ONU in PON is achieved. BAS sets user bandwidth information obtained during user authorization in OLT. The OLT achieves bandwidth control on a user basis, using bandwidth information set from the BAS. The present invention enables bandwidth control over users under the ONUs.

Abstract: To prevent a hung-up of communications due to changes in a radio wave condition resulting from frequent displacement of the terminals and changes in a number of the terminals, and to realize switching of the radio systems adapting to the radio condition. A radio communication system comprising: a base station for providing a plurality of radio systems, and terminals for communicating with the base station through the plurality of radio systems. The base station decides a priority of the radio system on which the each terminal will communicate thereafter and transmits paging signals of one of the plurality of radio systems which includes information on the decided priority to the each terminal.

Abstract: Bandwidth control over users accommodated under ONU in PON is achieved. BAS sets user bandwidth information obtained during user authorization in OLT. The OLT achieves bandwidth control on a user basis, using bandwidth information set from the BAS. The present invention enables bandwidth control over users under the ONUs.

Abstract: A reliable packet communication device capable of flexibly adding new functions. A packet communication device is composed of multiple interface elements (IFEs), switching elements (SWE) connecting these IFEs, and a routing manager element (RME) and may also if necessary comprise special functional packet processors (xFPs) capable of different special functions. The interface element and special functional packet processor are connected by a logical bus. For the purpose of connecting the interface elements and special functional packet processors through the switching element when the logical bus has a failure, the logical bus data format is made identical to the data format for passing data through the switch element and a selection circuit is installed in the interface element for selectively sending and receiving data to/from either the logical bus or the switching element.