JP2006180166A - Data exchange apparatus, data terminal device, network control apparatus and data transfer network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable preventing wasteful use of a path, by enabling ensuring arriving capability of an IP packet between terminals, without steadily setting a path between the terminals, having less traffic demand. <P>SOLUTION: The timing control function 21 of a network control apparatus 20 is used to set the update timing of switching information, with respect to a data exchange apparatus 10 and sets the selection timing of data buffers for data terminal devices 30, 40, 50 and 60, and causes the update timing with the selection timing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to data communication technology, and in particular, operates an optical path network composed of a DWDM (Dense Wavelength Division Multiplexing) optical path multiplexing link and an OXC (Optical Cross Connect) optical path switching node as an IP (Internet Protocol) network. It relates to network control technology.

In an optical path network composed of a conventional DWDM optical path multiplex link using an optical path and an OXC optical path switching node, signaling for optical path setting uses an IP address in an architecture called GMPLS (Generalized Multi Protocol Label Switching) Has been done. The optical path is a point-to-point type transfer path, and is set between terminals of the optical path network.
In an IP network, it is necessary to ensure reachability of IP packets for all terminals. For this reason, in order to operate the optical path network as an IP network, it is necessary to set the optical path in a mesh between terminals. However, in this method, not only the number of optical paths increases explosively with the increase in the number of terminals, but also a wide-band optical path is set between terminals with little traffic, so the economic efficiency is impaired. There is a problem.

  To solve this problem, an electrical router is installed, and this electrical router is used as a hub, and the optical path is set in a hub-and-spoke manner between terminals, ensuring IP packet reachability for all terminals. The technique which performs is proposed (for example, refer nonpatent literature 1 etc.). In this method, the increase in the number of optical paths can be suppressed to the same extent as the increase in the number of terminals. Moreover, it is possible to avoid a bottleneck of an electric router by allocating a cut-through type optical path between terminals having a lot of traffic.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
Murayama et al., "Arabic Design of Terabit-class Super Network", The Institute of Electrical Engineers of Japan, Communications Research Group CMN-04-17, June 2004

  However, although such a conventional technique can suppress the increase in the number of optical paths to the same extent as the increase in the number of terminals, an OXC that relays an optical path requires an optical path interface of the square of the number of terminals. Is done. This is because OXC relays the optical path received from the terminal to the electrical router. However, the optical paths addressed to these electrical routers are set in order to ensure the reachability of the IP packet, and if the traffic demand is small, the broadband property is not necessarily utilized effectively. This is also a factor that impairs economic efficiency.

  The present invention is for solving this problem, and it is possible to ensure the reachability of IP packets between terminals without constantly setting an optical path between terminals with low traffic demand, and waste of optical paths. An object of the present invention is to provide a data exchange device, a data terminal device, a network control device, and a data transfer network that can prevent the problem.

  In order to achieve such an object, a data exchange device according to the present invention is a data exchange device that relays and transfers data transmitted and received between data terminal devices via a data communication network, A plurality of transfer interface function units to be connected, a switch function unit that switches connection between these transfer interfaces based on the set switch information, and a switch control function unit that sets arbitrary switch information in the switch function unit The switch control function unit has a plurality of different switch information, and different switch information is sequentially set in the switch function unit.

  The data terminal device according to the present invention is a data terminal device that transmits and receives data to and from other terminals via a data communication network, and transmits a desired data to the destination terminal for each destination terminal. A plurality of data buffers for holding data to be transmitted, and a scheduler for sequentially selecting one of these data buffers and outputting the data in the data buffer to the transfer interface are provided.

  The network control device according to the present invention is a network control device for controlling a data communication network provided with the data exchange device and the data terminal device, and sets a switch information update timing for the data exchange device. A switch information update timing control function unit, a schedule timing control function unit that sets a data buffer selection timing for the data terminal device, and a timing synchronization function unit that synchronizes the update timing and the selection timing.

At this time, the schedule timing control function unit may set the timing to connect at different time intervals for each data terminal device pair.
The switch information update timing control function unit may set switch information corresponding to the configuration of the data communication network in the data exchange device.

  A data transfer network according to the present invention includes the data exchange device, a data terminal device, and a network control device.

According to the present invention, even if the number of terminals increases by using one path connecting the data terminal apparatus and the data exchange apparatus between different destination terminals, all the paths can be increased without increasing the number of paths. It becomes possible to ensure reachability of IP packets between terminals.
As a result, it is possible to ensure the reachability of IP packets between terminals without setting up a path between terminals with low traffic demand. Further, by increasing the use efficiency of the set optical path, it is possible to prevent waste of the optical path.

Next, embodiments of the present invention will be described with reference to the drawings.
[Data transfer network]
First, a configuration example of a data communication network according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration example of a data communication network according to an embodiment of the present invention.

  The data communication network includes a plurality of data terminal devices 30, 40, 50, 60 that transfer desired data in IP packets, and data (IP packets) transferred between the data terminal devices 30, 40, 50, 60. The data exchange device 10 relays and transfers, the data terminal devices 30, 40, 50, 60, and the network control device 20 that controls the data exchange device 10.

  In the following, the data exchange device 10 according to the present embodiment is composed of OXC optical path switching nodes, and the data communication network according to the present embodiment includes the data terminal devices 30, 40, 50, 60 and the data exchange device 10. A case will be described as an example in which the data communication network is composed of an optical path network connected by DWDM optical path multiplex links and this data communication network is operated as an IP network.

The data terminal device 30 includes a data exchange device 10 connected by an optical path via a transfer interface (transfer I / F) 34, a transfer function 32 for transferring data, and a network via a control interface (control I / F) 33. A transmission control function 31 for controlling the transmission destination selection timing in the transfer function 32 based on an instruction from the control device 20.
The data terminal device 40 uses the transfer function 42 that performs data transfer with the data exchange device 10 connected via an optical path via the transfer interface 44, and the transfer function 42 based on an instruction from the network control device 20 via the control interface 43. And a transmission control function 41 for controlling the selection timing of the transmission destination.

The data terminal device 50 has a transfer function 52 that performs data transfer with the data exchange device 10 connected via an optical path via the transfer interface 54, and a transfer function 52 based on an instruction from the network control device 20 via the control interface 53. And a transmission control function 51 for controlling the selection timing of the transmission destination.
The data terminal device 60 uses the transfer function 62 for performing data transfer with the data exchange device 10 connected by an optical path via the transfer interface 64, and the transfer function 62 based on an instruction from the network control device 20 via the control interface 63. And a transmission control function 61 for controlling the selection timing of the transmission destination.

The data exchange device 10 performs a relay transfer operation at the switch 12 based on an instruction from the network control device 20 via the control interface 17 and the switch 12 that switches the connection between the transfer interfaces 13 to 16 based on the set switch information. And a switch control function 11 for controlling the update timing of the switch information to be set.
The network control device 20 controls the transmission destination selection timing in the data terminal devices 30, 40, 50, and 60 through the control interfaces 23 to 26 and relays and transfers in the data exchange device 10 through the control interface 22. And a timing control function 21 for controlling the update timing of the switch information for setting the operation.

  In this data communication network, the control interface 33 of the data terminal device 30 and the control interface 23 of the network control device 20 are connected, the control interface 43 of the data terminal device 40 and the control interface 24 of the network control device 20 are connected, and the data terminal The control interface 53 of the device 50 and the control interface 25 of the network control device 20 are connected, the control interface 63 of the data terminal device 60 and the control interface 26 of the network control device 20 are connected, and the control interface 17 of the data exchange device 10 A control interface 22 of the network control device 20 is connected.

  Thereby, the network control device 20 is connected to all the devices 10, 30, 40, 50, 60 in the data communication network, and the timing control function 21 of the network control device 20 passes through the control interfaces 23 to 36. Are connected to the transmission control functions 31, 41, 51, 61 of all the data terminal apparatuses 30, 40, 50, 60 in the data communication network, and are connected to the switch control function 11 of the data exchange apparatus 10 via the control interface 22. Connected with.

In the present embodiment, one control interface is assigned to one device. At this time, the network control device 20 installs a schedule timing control function for each of the data terminal devices 30, 40, 50, 60, and one data terminal device determined in advance for each schedule timing control function The load of each schedule timing control function may be distributed, for example, by extracting only the topology information regarding.
Thereby, the network control device can control all the data terminal devices and data exchange devices in the network through the control interface. Accordingly, it is possible to synchronize the topology information and the data buffer used in all the data terminal devices and data exchange devices in the network.

[Data exchange device]
Next, a data exchange apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the data exchange apparatus according to the embodiment of the present invention.
The data exchange device 1 is a network device that relays and transfers data transferred between the data terminal devices 30, 40, 50, and 60, and includes a switch control function 11 and a switch 12.

The switch 12 is a functional unit that relays and transfers data between the desired transfer interfaces 13 to 16 by switching the connection between the transfer interfaces 13 to 16 based on the set switch information.
The switch control function 11 is a functional unit that controls the update timing of the switch information for setting the relay transfer operation in the switch 12 based on an instruction from the network control device 20 via the control interface 17, and includes a timer synchronization function 11A, a timer 11B, switch information selection function 11C, and switch information 11D, 11E, and 11F.

The timer 11B manages time information by increasing the timer value at regular intervals.
In the switch information 11D, 11E, and 11F, topology information indicating the connection relationship between the transfer interfaces 13 to 16 of the switch 12 is stored.
The control interface 17 changes the other device, the switching device timer setting request for changing the maximum value of the timer value, the switching device timer control request for requesting resetting of the timer value, and the timer value for starting application of each switch information. And a switching device timer reference request for referring to a timer value, a maximum value of the timer value, and a timer value for starting application of each switch information.

  The timer synchronization function 11A receives an exchange device timer setting request from another device, sets a maximum timer value according to the request, a function to reset the timer value when the timer value reaches the maximum value, A function for receiving a switching device timer control request from another device and resetting the timer value according to the request, and a timer value for starting application of each switch information according to the request when a switching device timer threshold change request is received from the other device. When the timer value reaches the timer value at which the setting and the timer value start to apply another switch information, a switch information change trigger to request the adoption of the switch information corresponding to the timer value is used as the switch information selection function. The function obtained by referring to the timer 11B when the transmission function and the exchange device timer reference request are received from another device. Mer value, by having a function of transmitting the timer value to the other device to start the application of the maximum value and the switch information of the timer value, and a function to reduce the share of other devices and timer information.

When the switch information selection function 11C receives the switch information change trigger from the timer synchronization function 11A, the switch interfaces 12 to 16 of the switch 12 realize the topology described in the switch information included in the switch information change trigger. It has a function of switching between the circuits.
The transfer interfaces 13 to 16 have a function of transmitting / receiving packets to / from other apparatuses via an optical path.

  As a result, the data exchange apparatus 10 selects and updates any one of the switch information 11D, 11E, and 11F in time series, and resets one optical path between data terminal apparatuses that are different in time series. It is possible to go. Therefore, it is possible to set an optical path at least once between all data terminal devices within a certain period, and to ensure reachability of IP packets between all data terminal devices within this period. It becomes possible.

[Data terminal equipment]
Next, the configuration of the data terminal device according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is an explanatory diagram showing the configuration of the data terminal device according to the embodiment of the present invention.
The data terminal device 30 is a network device that transfers desired data in IP packets via the data exchange device 10 connected by an optical path, and includes a transfer function 32, a terminal function 35, and a transmission control function 31. . Here, the data terminal device 30 will be described as an example, but the data terminal devices 40, 50, and 60 have the same configuration.

The transfer function 32 has a routing function 32A, data buffers (output queues) 32B to 32D, and a scheduler 32E, and the transmission control function 31 has a timer synchronization function 31A and a timer 31B.
The transfer interface 34 has a function of transmitting and receiving packets to and from other devices.
The transfer function 32 transmits the received packet to the terminal function 35.

  When the terminal function 35 receives a packet from the transfer function 32 and the destination address of the packet is an address indicating the apparatus itself, the terminal function 35 removes the header of the packet and obtains the data part after removing the header. A function of analyzing the data part when the packet is removed, and a function of transmitting the packet to the routing function 32A of the transfer function 32 when a new packet is obtained after removing the header. Further, when the destination address of the packet is not an address indicating the apparatus itself, it has a function of transmitting the packet to the routing function 32A of the transfer function 32.

  The routing function 32A collects network route information by dynamic routing or static routing using routing protocols such as BGP (Border Gateway Protocol), OSPF (Open Shortest Path First), RIP (Routing Information Protocol), etc. A function for identifying the next hop terminal for the function, a function for identifying the data buffer for the next hop terminal, and a packet received from the terminal function, identify the next hop terminal with reference to the destination address described in the header, It has a function of specifying a data buffer to be stored and storing the received packet in the specified data buffer.

The data buffers 32B to 32D have a function of temporarily storing packets, and are installed for each next hop terminal (destination terminal).
The control interface 33 transmits a terminal timer setting request for changing the maximum value of the timer value, a terminal timer control request for requesting resetting of the timer value, and a packet stored in each data buffer to each transfer interface. A terminal timer threshold change request for changing a timer value to be started, and a terminal timer reference request for referring to a timer value, a maximum value of the timer value, and a timer value for starting transmission of a packet stored in each data buffer to each transfer interface It has a function to send and receive.

  The timer synchronization function 31A receives a terminal timer setting request from another device, sets a maximum timer value according to the request, resets the timer value when the timer value reaches the maximum value, A function to receive a terminal timer control request from a device and reset the timer value according to the request, and when a terminal timer threshold value change request is received from another device, a packet stored in each data buffer is transmitted to each transfer interface according to the request The function to set the timer value to start, and when the timer value reaches the timer value that changes the data buffer that sends the stored packet to each transfer interface, the data buffer that sends the stored packet to each transfer interface is changed. A function to send a requested buffer change trigger to the scheduler 32E, etc. When the terminal timer reference request is received from the device, the timer value obtained by referring to the timer 31B, the maximum value of the timer value, and the timer value for starting transmission of the packet stored in each data buffer to each transfer interface By having the function of transmitting to the other device, it has a function of sharing timer information with other devices.

The timer 31B manages time information by increasing the timer value at regular intervals.
When the scheduler 32E receives a function for transmitting a packet stored in the data buffer to the transfer interface and a use buffer change trigger from the timer synchronization function 31A, the scheduler 32E is stored in a certain data buffer. A function of stopping transmission of the received packet and starting transmission of the packet stored in the data buffer described in the use buffer change trigger.

In this embodiment, since the transfer interface of the data terminal apparatus has only one interface, when one data buffer is used, the stored packets of other data buffers are not transmitted. When there are two transfer interfaces, two data buffer storage packets are transmitted, and one data buffer storage packet is not transmitted.
As a result, each data terminal device is equipped with a data buffer for each destination, and data can be transferred to the target terminal by synchronizing the data output timing with the optical path setting timing. Accordingly, by reusing one optical path, it is possible to ensure the reachability of IP packets among all terminals without increasing the number of optical paths even if the number of terminals increases.

[Network control device]
Next, the configuration of the network control apparatus according to the embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the network control apparatus according to the embodiment of the present invention.
The network control device 20 is a network device that controls the data terminal devices 30, 40, 50, 60 and the data exchange device 10, and includes a timing control function 21 and control interfaces 22 to 26.

The timing control function 21 includes a timing synchronization function 21A, schedule timing control functions 21B to 21E, and a switch information update timing control function 21F.
The control interfaces 23 to 26 include a terminal timer setting request for changing the maximum timer value, a terminal timer control request for requesting resetting of the timer value, and a packet stored in each data buffer. Terminal timer threshold change request for changing a timer value for starting transmission to each transfer interface, and a timer for referring to the timer value, its maximum value, and the timer value for starting transmission of packets stored in each data buffer to each transfer interface It has a function to send and receive reference requests.

  Further, the control interface 22 applies an exchange device timer setting request for changing the maximum value of the timer value to the data exchange device 10, an exchange device timer control request for requesting resetting of the timer value, and application of each switch information. A switching device timer threshold change request for changing a timer value for starting a switching device, and a switching device timer reference request for referring to a timer value, its maximum value, and a timer value for starting application of each switch information. Yes.

  The timing synchronization function 21A holds a plurality of topology patterns indicating connection relationships between transfer interfaces held by data terminal devices and data exchange devices in the network, timer values for starting application of these topology patterns, and maximum values thereof. Using a function and a timer owned by itself, periodically sends a terminal timer reference request to all data terminal devices in the network, and periodically sends an exchange device timer reference request to all data exchange devices in the network. Therefore, when there is a difference between the function that periodically monitors the information held by all the devices in the network and the timer value that each device has, the all devices in the network Terminal timer control to all data terminal devices in the network to reset the timer value of Send a determined, and a function of transmitting a switching device timer control request to all the data exchange device in the network.

  The schedule timing control devices 21B to 21E should be set in each data terminal device in the network from the plurality of topology patterns held by the timing synchronization function 21A, the timer value for starting application of the topology pattern, and the maximum value of the timer value. A function for extracting the maximum timer value and the timer value for starting transmission of packets stored in each data buffer to each transfer interface, and a terminal timer setting request and a terminal timer threshold change request are created from the extracted information. The above function is operated when the topology information held by the timing synchronization function 21A and the maximum value of the timer value change, and the timer value to be set for each data terminal device in the network. The maximum value and the packet stored in each data buffer A function of extracting a timer value to start sending to the transfer interface, and a function of transmitting to the relevant device from these extracted information to create a terminal timer setting request and the terminal timer threshold change request.

  The switch information update timing control function 21F has a timer value to be set for each data exchange device in the network from the plurality of topology patterns held by the timing synchronization function 21A, the timer value for starting the application of the topology pattern, and the maximum value thereof. A function for extracting the maximum value of the switch and a timer value for starting the application of each switch information, a function for creating an exchange device timer setting request and an exchange device timer threshold change request from the extracted information, and transmitting to the corresponding device When the topology information held by the timing synchronization function 21A and the maximum value of the timer value change, the above function is operated, and the maximum value of the timer value to be set in each data exchange apparatus in the network and the application of each switch information From the extracted information and the function to extract the timer value to be started And a function of transmitting to the appropriate device by creating a conversion device timer setting request and exchange device timer threshold change request.

  The switch information update timing control function 21F has a function of setting switch information corresponding to the configuration of the data communication network in the data exchange apparatus 10. When the configuration (topology) of the data communication network is changed, the switch information is generated according to an operator instruction and set in the data exchange device 10. At this time, the setting timing for new switch information is also set at the same time.

Thereby, the topology information used by the data exchange device and the data terminal device in the network is synchronized, and packet transfer according to the applied topology information becomes possible.
Therefore, when the data exchange device resets one optical path between different terminals in time series, it is possible to establish establishment of a relay route and packet transfer in accordance therewith.

[Data communication network operations]
Next, the operation of the data communication network according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is an example of a switch information update pattern in the data communication network according to the embodiment of the present invention.

In the present embodiment, the timing control function 21 of the network control device 20 has the topology patterns of patterns A to C, and is used as the switch information 11D to 11F by the switch control function 11 of the data exchange device 10.
In the pattern A, in the data exchange device 10, the transfer interface 13 and the transfer interface 15 are connected, and the transfer interface 14 and the transfer interface 16 are connected.

The transfer interface 13 is connected to a transfer interface 34 held by the data terminal device 30, the transfer interface 15 is connected to a transfer interface 54 held by the data terminal device 50, and the transfer interface 14 is transferred by the data terminal device 40. The transfer interface 16 is connected to a transfer interface 64 held by the data terminal device 60.
Therefore, the data terminal device 30 and the data terminal device 50 are connected, and the data terminal device 40 and the data terminal device 60 are connected.

  At this time, in the data terminal device 30, a packet is transmitted to the transfer interface 34 from the data buffer in which the data terminal device 50 is managed as the next hop, and no packet is transmitted from other data buffers. Similarly, in the data terminal device 40, a packet is transmitted to the transfer interface 44 from the data buffer in which the data terminal device 60 is managed as the next hop, and no packet is transmitted from the other data buffer. The packet is transmitted from the data buffer in which the data terminal device 30 is managed as the next hop to the transfer interface 54, and no packet is transmitted from the other data buffer. In the data terminal device 60, the data terminal device 40 The packet is transmitted to the transfer interface 64 from the data buffer managed as, and the packet is not transmitted from the other data buffer.

Next, in pattern B, in the data exchange device 10, the transfer interface 13 and the transfer interface 16 are connected, and the transfer interface 14 and the transfer interface 15 are connected. The transfer interface 13 is connected to a transfer interface 34 held by the data terminal device 30, the transfer interface 16 is connected to a transfer interface 64 held by the data terminal device 60, and the transfer interface 14 is transferred by the data terminal device 40. The transfer interface 15 is connected to a transfer interface 54 owned by the data terminal device 50.
Therefore, the data terminal device 30 and the data terminal device 60 are connected, and the data terminal device 40 and the data terminal device 50 are connected.

  At this time, in the data terminal device 30, a packet is transmitted to the transfer interface 34 from the data buffer in which the data terminal device 60 is managed as the next hop, and no packet is transmitted from other data buffers. Similarly, in the data terminal device 40, a packet is transmitted to the transfer interface 44 from the data buffer in which the data terminal device 50 is managed as the next hop, and no packet is transmitted from other data buffers. The packet is transmitted from the data buffer in which the data terminal device 40 is managed as the next hop to the transfer interface 54, and no packet is transmitted from the other data buffer. In the data terminal device 60, the data terminal device 30 The packet is transmitted to the transfer interface 64 from the data buffer managed as, and the packet is not transmitted from the other data buffer.

Next, in pattern C, in the data exchange device 10, the transfer interface 13 and the transfer interface 14 are connected, and the transfer interface 15 and the transfer interface 16 are connected.
The transfer interface 13 is connected to the transfer interface 34 held by the data terminal device 30, the transfer interface 14 is connected to the transfer interface 44 held by the data terminal device 40, and the transfer interface 15 is transferred by the data terminal device 50. The transfer interface 16 is connected to a transfer interface 64 held by the data terminal device 60.
Therefore, the data terminal device 30 and the data terminal device 40 are in a connection relationship, and the data terminal device 50 and the data terminal device 60 are in a connection relationship.

  At this time, in the data terminal device 30, a packet is transmitted to the transfer interface 34 from the data buffer in which the data terminal device 40 is managed as the next hop, and no packet is transmitted from other data buffers. Similarly, in the data terminal device 40, a packet is transmitted to the transfer interface 44 from the data buffer managed as the next hop by the data terminal device 30, and no packet is transmitted from other data buffers. The packet is transmitted from the data buffer in which the data terminal device 60 is managed as the next hop to the transfer interface 54, and no packet is transmitted from the other data buffer. In the data terminal device 60, the data terminal device 50 The packet is transmitted to the transfer interface 64 from the data buffer managed as, and the packet is not transmitted from the other data buffer.

The timing control function 21 of the network control device 20 has topology patterns A to C, a timer value for starting application of the topology pattern, and a maximum value of the timer value.
For example, assuming that the maximum timer value 300, the pattern A application start timer value 0, the pattern B application start timer value 100, and the pattern C application start timer value 200, when the timer value held by each device indicates 100, the pattern B Switch used in each device is changed so that pattern C is applied when the timer value held by each device indicates 200. Change the information and usage data buffer.

When the timer value of the device reaches the maximum timer value 300, the timer value is reset, and the use switch information and the use data buffer in each device are changed so that the pattern A is applied. As a result, when the data exchange apparatus resets one optical path between different terminals in time series in a time series, the optical switching is performed at least once between all terminals within a certain period. A path can be set, and reachability of IP packets among all terminals can be ensured within this period.
Each terminal can transfer data to the target terminal by synchronizing the data output timing with the optical path setting timing.
As a result, by using a single optical path, it is possible to ensure reachability of IP packets among all terminals without increasing the number of optical paths even if the number of terminals increases.

FIG. 6 is an example of an update cycle of each pattern in the switch information update pattern of FIG.
When the example shown in FIG. 5 is applied, the time on the horizontal axis indicates a timer value, and one time interval on the time axis indicates the timer value 100.
At time T1 in FIG. 6, the timer value indicates 100, the use switch information and the use data buffer in each device are changed so that the pattern B is applied, and at time T2, the timer value indicates 200. Use switch information and use data buffer in each device are changed so that C is applied. At time T3, the timer value indicates 300, the timer value is reset, and the use switch information and the use data buffer in each device are changed so that the pattern A is applied.

  Similarly, the timer value indicates 100 at the time T4, the use switch information and the use data buffer in each device are changed so that the pattern B is applied, the timer value indicates 200 at the time T5, The use switch information and the use data buffer in each apparatus are changed so that the pattern C is applied. At time T6, the timer value indicates the maximum timer value 300, the timer value is reset, and the use switch information and the use data buffer in each device are changed so that the pattern A is applied.

By repeating each operation and applying each pattern periodically, the data exchange apparatus resets one optical path between different terminals in time series in time series. An optical path can be set up at least once between all terminals within a certain period, and reachability of IP packets between all terminals can be ensured within this period.
Each terminal can transfer data to the target terminal by synchronizing the data output timing with the optical path setting timing. As a result, by using a single optical path, it is possible to ensure reachability of IP packets among all terminals without increasing the number of optical paths even if the number of terminals increases.

FIG. 7 shows a tuning example of the path setting time in the switch information update pattern of FIG.
The application time of each pattern is tuned according to the amount of traffic between the data terminal devices, that is, the usage rate of each data buffer in each data terminal device.
Applying the example shown in FIG. 5 described above, the relationship between the application time of phase 1, the application time of phase 2 and the application time of phase 3 is changed to 3: 1: 2, and the maximum timer value is changed to 60 It shall be. At this time, one time interval indicates a timer value of 10.

  At time T11 in FIG. 7, the timer value indicates 30, and the use switch information and the use data buffer in each device are changed so that the pattern B is applied. At time T12, the timer value indicates 40, and the pattern The use switch information and the use data buffer in each device are changed so that C is applied. At time T13, the timer value indicates the maximum timer value 60, the timer value is reset, and the use switch information and the use data buffer in each device are changed so that the pattern A is applied.

  Similarly, the timer value indicates 30 at the time T14, the use switch information and the use data buffer in each device are changed so that the pattern B is applied, the timer value indicates 40 at the time T15, The use switch information and the use data buffer in each apparatus are changed so that the pattern C is applied. At time T16, the timer value indicates the maximum timer value 60, the timer value is reset, and the use switch information and the use data buffer in each device are changed so that the pattern A is applied.

By repeating these operations and applying each pattern periodically, the optical path setup time is adjusted for each pair of terminals, so that a long-time optical path can be set up between terminals with high traffic demand. It is possible to set up an optical path for a short time between terminals with few.
Therefore, it is possible to increase the use efficiency of the optical path.

  In the above description, an example is described in which an optical path network composed of DWDM (Dense Wavelength Division Multiplexing) optical path multiplexing links and OXC (Optical Cross Connect) optical path switching nodes is operated as an IP (Internet Protocol) network. However, the path for connecting the data terminal device and the data exchange device is not limited to the optical path, and the data communication network configured using other paths is also implemented in the same manner as described above. The same effect can be obtained.

  In addition, the functional units of the data exchange device 10, the network control device 20, and the data terminal devices 30, 40, 50, 60 described above may be configured with dedicated signal processing circuits, such as a CPU and a DSP. It may be realized by an arithmetic processing unit formed by cooperating the microprocessor and a predetermined program.

It is a block diagram which shows the structural example of the data communication network concerning one embodiment of this invention. It is a block diagram which shows the structure of the data exchange apparatus concerning one embodiment of this invention. It is a block diagram which shows the structure of the data terminal device concerning one embodiment of this invention. It is a block diagram which shows the structure of the network control apparatus concerning one embodiment of this invention. It is an example of the switch information update pattern in the data communication network concerning one embodiment of the present invention. It is an example of the update cycle of each pattern in the switch information update pattern of FIG. 6 is a tuning example of a path setting time in the switch information update pattern of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Data exchange apparatus, 11 ... Switch control function, 11A ... Timer synchronous function, 11B ... Timer, 11C ... Switch information selection function, 11D-11F ... Switch information, 12 ... Switch, 13-16 ... Transfer interface, 17 ... Control Interface, 20 ... Network controller, 21 ... Timing control function, 21A ... Timing synchronization function, 21B-21E ... Schedule timing control function, 21F ... Switch information update timing control function, 22 ... Control interface, 23-26 ... Control interface, 30, 40, 50, 60 ... data terminal device, 31, 41, 51, 61 ... transmission control function, 31A ... timer synchronization function, 31B ... timer, 32, 42, 52, 62 ... transfer function, 32A ... routing function, 32B to 32D ... Data buffer 32E ... scheduler, 33,43,53,63 ... control interface, 34, 44, 54, 64 ... transfer interface, 35 ... terminal function.

Claims (6)

A data exchange apparatus for relaying and transferring data transmitted and received between data terminal apparatuses via a data communication network,
A plurality of transfer interface function units each connected to the data terminal device;
A switch function unit for switching the connection between these transfer interfaces based on the set switch information;
A switch control function unit for setting arbitrary switch information in the switch function unit,
The switch control function unit has a plurality of different switch information, and sequentially sets different switch information in the switch function unit. A data terminal device that transmits and receives data to and from other terminals via a data communication network,
A transfer interface for transmitting desired data;
A plurality of data buffers for holding data to be transmitted to the destination terminal for each destination terminal;
A data terminal device comprising: a scheduler that sequentially selects one of these data buffers and outputs the data in the data buffer to the transfer interface. A network control device for controlling a data communication network provided with the data exchange device according to claim 1 and the data terminal device according to claim 2,
A switch information update timing control function unit for setting the update timing of the switch information for the data exchange device;
A schedule timing control function unit for setting the selection timing of the data buffer for the data terminal device;
A network control apparatus comprising: a timing synchronization function unit that synchronizes the update timing and the selection timing. The network control device according to claim 3, wherein
The network control device according to claim 1, wherein the schedule timing control function unit sets the timing so that the data terminal devices are connected at different time intervals. The network control device according to claim 3, wherein
The switch information update timing control function unit sets switch information corresponding to the configuration of the data communication network to the data exchange device. A data transfer network comprising the data exchange device according to claim 1, the data terminal device according to claim 2, and the network control device according to claim 3.

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