Abstract: A data transport system comprises transport apparatus and at least one computer. The transport apparatus construct a second network coupled to a first network which is constructed by a communication apparatus. A logical path is built between a first transport apparatus and the computer. The first transport apparatus is configured to: hold management information, which associates identification information of a port with logical path identification information; refer to the management information to identify the logical path identification information that is associated with the port through which the control information has been received; and assign the identified logical path identification information to the control information, and transmit the control information over the logical path. The computer assigns the logical path identification information assigned to the control information to response information, and transmits the response information to the second network.

Abstract: In an extensive distribution system with no delay guarantee network used as a relay network, an influence of a fluctuation of a communication delay time is avoided to conduct a high-precision time synchronization. First and second delay control devices installed in junctions between communication networks and a relay network, respectively, have functions of retaining first and second time information, and setting a first relay network passing time of a first communication signal directed from a time dissemination device toward a time receiving device through a relay network, and a second relay network passing time of a second communication signal directed from the time receiving device toward the time dissemination device, respectively. In measurement of communication delay time of the first communication network and the second communication network prior to time synchronization, the first and second relay network passing times are unified in advance to exclude uncertainty of the communication time.

Abstract: When a communication path between a user site and a dual-homed data center is made redundant, a communication between the user site and a server within a data center can be continued. An edge node DCE-1 of a data center 40-1 and edge nodes TPE-1, TPE-2 of a transport network are connected to each other by a link TPE-1-1 and a link TPE-2-1, respectively. The edge nodes TPE-3 and TPE-1, TPE-2 that hold a node AE51 of a user site 50 are set with an LSP 110 of an active system, and an LSP 120 of a backup system, respectively. One of the links is active, and the other link is backup, and the LSP of the TPE node having the active link in the LSP 100 and the LSP 120 is made active. The respective links are prioritized, and the links are switched to an active state in order from the links higher in the order of priority when a link failure or an LSP failure occurs.

Abstract: A transmission device uses transmission delay time of reciprocation with the terminal and time information of the transmission device to create a correction value of time information of the terminal and transmits it to the terminal. The terminal includes expected arrival time information based on the time information of the terminal and the correction value received from the transmission device in a frame transmitted to the transmission device. The transmission device compares reception time of the frame with the expected arrival time information in the frame. If they match, the time information of the terminal synchronizes with the time information of the transmission device. If they do not match, the transmission device transmits a new correction value to the terminal. The terminal transmits a frame including expected arrival time information using the new correction value to the transmission device.

Abstract: A transmission network system includes a network terminating device connected to a user terminal and an authentication information device connected to the network terminating device through a transmission network. The transmission network is connected to a reference clock that holds a reference time. The network terminating device includes a terminating internal clock that synchronizes with the reference clock, when receiving a first frame from the user terminal, generates a second frame including a time outputted from the terminating internal clock as a request time on the basis of the first frame, and transmits the second frame to the authentication information device. The authentication information device generates time authentication information based on the request time included in the received second frame, generates a third frame including the generated time authentication information, and transmits the third frame to the transmission network.

Abstract: A first communication apparatus and a second communication apparatus are coupled to each other via predetermined communication paths. The control apparatus is configured to: acquire an available bandwidth in each of the predetermined communication paths; define such sub-paths as to start from the first communication apparatus to reach the second communication apparatus and that one of the sub-paths pass through one of the communication paths; determine sub-path bandwidths for the sub-paths in accordance with the acquired available bandwidths; and transmit information for identifying each of the sub-paths and information indicating the sub-path bandwidths to the first communication apparatus by including the information in a setting instruction to set the sub-paths for the first communication apparatus and the second communication apparatus.

Abstract: A communication device on a time equivalence assurance network that guarantees the receiving sequence of packets sent to all users so that even if a user session is re-sent, a function operates to alleviate the resultant effects and make the send and receive timing approach the initial timing. An edge communication device on a provider network identifies the sessions of each user subscriber terminal, and stores and monitors the time information attached by a sequence information attachment function. Even if a packet is resent, the packet will at this time be resent with attached sequence information based on the past time originally attached to the packet, and not sequence information based on the current resending time.

Abstract: Provided is a communication system which is provided with a plurality of communication devices and transfers a packet between the plurality of communication devices through a communication path. When a packet is looped back at any of the communication devices on the communication path to verify connectivity of the communication path, a first communication device of the plurality of communication devices stores, in a first region of header information of the packet, first information for designating the communication device at which the packet is looped back, further stores, in a second region of the header information of the packet, second information on a loopback point in the designated communication device at which the packet is looped back, and sends the packet to which the first information and the second information have been added.

Abstract: A transmission network is comprised of a network management system for collectively managing and controlling a plurality of transmission devices coupled mutually through transmission routes and the transmission network as well. The network management system includes a plane management table adapted to manage transmission planes defined as a set of paths in the transmission network, and the plane management table has the function to set and manage a transmission plane (working plane) applied during normal operation and besides, a single or a plurality of transmission planes (protection planes) applicable in the event of occurrence of a fault in the transmission network. Then, when a fault occurs in the transmission network, the network management system changes the applied plane to a suitable transmission plane.

Abstract: A shelf of a network synchronization device includes: a clock input reception unit which receives an input of a clock signal; a clock output unit which outputs a clock signal; a clock interruption detection unit which detects a clock interruption if the clock input reception unit does not receive a clock; an AIS signal detection unit which detects an AIS signal if the AIS signal is received through the clock input reception unit; an AIS signal generation unit which generates the AIS signal; an alarm control unit which outputs a predetermined alarm notification when the AIS signal detection unit does not detect the AIS signal if the clock interruption detection unit detects the clock interruption; and an output signal selection unit which outputs the AIS signal generated by the AIS signal generation unit to the clock output unit if the clock interruption detection unit detects the clock interruption.

Abstract: In an extensive distribution system with no delay guarantee network used as a relay network, an influence of a fluctuation of a communication delay time is avoided to conduct a high-precision time synchronization. First and second delay control devices installed in junctions between communication networks and a relay network, respectively, have functions of retaining first and second time information, and setting a first relay network passing time of a first communication signal directed from a time dissemination device toward a time receiving device through a relay network, and a second relay network passing time of a second communication signal directed from the time receiving device toward the time dissemination device, respectively. In measurement of communication delay time of the first communication network and the second communication network prior to time synchronization, the first and second relay network passing times are unified in advance to exclude uncertainty of the communication time.

Abstract: A packet transfer apparatus connects two networks of different protocols. The packet transfer apparatus, connected to a first communication network and a second communication network, performs the steps of: storing first destination correspondence information; receiving a packet of the first communication protocol; based on the first destination correspondence information, determining destination information of a packet of the second communication protocol corresponding to destination information of the received packet of the first communication protocol; generating the header of the packet of the second communication protocol, based on the determined destination information of the packet of the second communication protocol; converting the received one or more packets of the first communication protocol into one or more packets of the third communication protocol; and adding the generated header of the packet of the second communication protocol to the packets of the third communication protocol.

Abstract: A data transport system comprises transport apparatus and at least one computer. The transport apparatus construct a second network coupled to a first network which is constructed by a communication apparatus. A logical path is built between a first transport apparatus and the computer. The first transport apparatus is configured to: hold management information, which associates identification information of a port with logical path identification information; refer to the management information to identify the logical path identification information that is associated with the port through which the control information has been received; and assign the identified logical path identification information to the control information, and transmit the control information over the logical path. The computer assigns the logical path identification information assigned to the control information to response information, and transmits the response information to the second network.

Abstract: An identifier management apparatus capable of setting identifier conversion information of a new user without affecting identifier conversion processings of other users, and an identifier management method. The identifier management apparatus converts an identifier given to communication data. Its memory stores multiple hash functions, output values of the hash functions corresponding to the respective plurality of hash functions, multiple entry tables that manage the identifier conversion information indicating a correspondence between the input identifier being an input value of the hash function and an output identifier obtained by converting the input identifier, and a management table for managing a setting status of the identifier conversion information in each entry table.

Abstract: It is ensured to prevent a user from misrepresenting a time stamp, and to send out packets in sequence in which the packets are accepted to all users who are geographically isolated from each other. A unique time stamp impartation function is realized by respective communication devices on a net inside an administrative responsibility range of a communication common carrier, hardly accessible by a user. If a packet with a time stamp imparted by a subscriber terminal, provided thereto, is received, the respective communication devices positioned on the net inside the administrative responsibility range nullify the relevant time stamp in order to prevent misrepresentation of the time stamp, by a user outside the administrative responsibility range, and restores the packet from the subscriber together with the time stamp when transferring the packet to the outside of the administrative responsibility range.

Abstract: A transmission network system includes a network terminating device connected to a user terminal and an authentication information device connected to the network terminating device through a transmission network. The transmission network is connected to a reference clock that holds a reference time. The network terminating device includes a terminating internal clock that synchronizes with the reference clock, when receiving a first frame from the user terminal, generates a second frame including a time outputted from the terminating internal clock as a request time on the basis of the first frame, and transmits the second frame to the authentication information device. The authentication information device generates time authentication information based on the request time included in the received second frame, generates a third frame including the generated time authentication information, and transmits the third frame to the transmission network.

Abstract: In interworking systems that utilize IP/MPLS protocol processing to operate a centralized control server within a MPLS-TP network as a pseudo-router unit; a system improves the utilization rate of the MPLS-TP network by establishing default paths beforehand as a precondition to coupling between MPLS-TP network edge devices and mapping a plurality of IP/MPLS paths between the same edge devices to the common default paths when mapping to provide IP/MPLS network connectivity.

Abstract: When a communication path between a user site and a dual-homed data center is made redundant, a communication between the user site and a server within a data center can be continued. An edge node DCE-1 of a data center 40-1 and edge nodes TPE-1, TPE-2 of a transport network are connected to each other by a link TPE-1-1 and a link TPE-2-1, respectively. The edge nodes TPE-3 and TPE-1, TPE-2 that hold a node AE51 of a user site 50 are set with an LSP 110 of an active system, and an LSP 120 of a backup system, respectively. One of the links is active, and the other link is backup, and the LSP of the TPE node having the active link in the LSP 100 and the LSP 120 is made active. The respective links are prioritized, and the links are switched to an active state in order from the links higher in the order of priority when a link failure or an LSP failure occurs.

Abstract: When a communications carrier uses another company's network as a relay network, it is necessary to monitor the health of and to perform maintenance for the lines from end to end in the other company's network as well as the network managed by this carrier. Terminal devices capable of terminating a CCM frame or other OAM signal are installed in users bases, and the health is monitored from end to end between the bases. Furthermore, a control device that controls the terminal devices is installed in the VLAN network used by the user, and remote control of the terminal devices is implemented from the controller. Table information held by the controller is managed collectively under the leadership of an operator, and information about the subordinate terminal devices connected to the controller is reported to the operator on the basis of results of the MAC learning by the controller.

Abstract: If, in a situation where the information about the OAM function of a first network including router networks is collected, a fault affecting a service used by a user occurs in a transmission network, which is a second network that acts as a relay for the first network and includes a plurality of transmission devices having a fault monitoring function, the transmission network promptly reports the fault to the router networks by actively using the OAM function of the router networks in order to achieve rapid fault recovery.