JP4765979B2 - Method, system and apparatus for relaying between optical burst switching networks by wavelength path - Google Patents

Description

  The present invention relates to an optical burst switching (OBS) network, and more specifically, data transmitted and received between two optical burst switching networks using a GMPLS (Generalized Multi-Protocol Label Switching) technology or the like. The present invention relates to a technology for relaying through a network for setting a path.

  The OBS network is a network in which, when there is data to be transmitted, a certain wavelength is allocated for a time required for this data transmission, and the data to be transmitted is transmitted as an optical burst signal of the allocated wavelength. And an OBS core node (see, for example, Non-Patent Document 1).

  When there is data to be transmitted, the OBS edge node first transmits a control packet called BCP (Burst Control Packet) at a wavelength allocated for the control packet. This control packet includes data destination information and wavelength information used by the data. The OBS edge node transmits data as an optical burst signal of the wavelength notified by the control packet after a predetermined offset period has elapsed from the transmission of the control packet, and transmits a control packet indicating transmission completion after transmitting the optical burst signal.

  On the other hand, when the OBS core node receives the control packet, the OBS core node transfers the control packet based on the included destination information and transmits the optical burst signal received after the offset period elapses to the same path as the control packet. Further, upon reception of a control packet indicating completion of optical burst signal transmission, resources for transfer are released.

llia Baldine et al, “JumpStart: A Just-in-Time Signaling Architecture for WDM Burst-Switched Networks”, IEEE Communications Magazine, February 2002.

  Consider connecting two OBS networks with an optical network using GMPLS technology. In the GMPLS optical network, each optical transmission device recognizes the network topology by exchanging link information, and the optical transmission device that requires the wavelength path calculates the route of the wavelength path to be set and A wavelength path setting request message is transmitted to each of the optical transmission devices to set the wavelength path.

  Since the GMPLS optical network relays control packets and optical burst signals that use different wavelengths, respectively, the destination OBS network may receive the optical burst signal first. Will not be able to transmit optical burst signals.

  Even if the wavelength path is set and the two OBS networks are connected so as to solve the above problem and guarantee the order of the control packet and the optical burst signal, a certain amount of processing is required for setting and releasing the wavelength path. Since time is required, setting and canceling a wavelength path for each optical burst signal increases processing delay or causes quality degradation due to data loss. However, maintaining the wavelength path regardless of the generation of the optical burst signal reduces the bandwidth utilization efficiency of the GMPLS optical network.

  Accordingly, an object of the present invention is to provide a method, system, and apparatus for solving the above-described problems and relaying data transmitted / received between two OBS networks through an optical network that sets a wavelength path as necessary. .

According to the system of the present invention,
A system including a first device and a second device, wherein the first device generates means for generating an optical burst signal from transmission data, and the next optical signal belonging to the same destination or the same communication as the optical burst signal. Means for determining whether or not to maintain the wavelength path based on a time interval with the burst signal, and means for generating a control packet of the optical burst signal including a determination result of the determining means, The apparatus 2 includes means for performing wavelength path setting control for a network for setting a wavelength path, and the means for performing setting control is set in the network for transferring the received control packet and the optical burst signal. When the set wavelength path is used, the set wavelength path is maintained or released according to the determination result included in the control packet.

According to another embodiment of the system of the present invention,
The determining means has a threshold value based on the sum of the time required for setting the wavelength path in the network and the time required for cancellation, and determines that the wavelength path is maintained when the time interval is less than the threshold value. It is also preferable.

Also, according to another embodiment of the system of the present invention,
It is also preferable that the determining means classifies the transmission data according to the tolerance for delay of the transmission data, and determines whether or not to maintain the wavelength path by applying a different threshold value to each.

According to the apparatus of the present invention,
Based on a time interval between a means for generating an optical burst signal from transmission data and a next optical burst signal belonging to the same destination or the same communication as the optical burst signal, the optical burst signal passes through a network for setting a wavelength path. Means for determining whether or not to maintain the wavelength path that relays the optical burst signal after relaying, and means for generating a control packet for the optical burst signal, including a determination result of the determining means It is characterized by having.

According to the method of the present invention,
A method of relaying data transmitted from a first network that performs optical burst switching to a third network that performs optical burst switching by a second network that sets a wavelength path, A wavelength path based on a step of generating an optical burst signal from transmission data in the first device and a time interval between the optical burst signal and a next optical burst signal belonging to the same destination or the same communication in the first device; A first network and a second network, a step of generating a control packet of the optical burst signal including a determination result in the determination step in the first device, and a first network and a second network Connected to the second network, the second device for controlling the setting of the wavelength path for the second network is connected to the second network and the third network. A step of transmitting the control packet and the optical burst signal to a wavelength path set with a network interconnection device, and a second device according to the determination result included in the control packet, the set wavelength And a step of maintaining or canceling the path.

  If the time interval between optical burst signals belonging to the same destination or the same communication is short, the wavelength path is maintained, and if not, it is temporarily canceled to prevent the optical burst signal quality degradation and Balance effective use of network bandwidth. In determining whether to maintain the wavelength path, a threshold value based on the sum of the time required for setting the wavelength path in the network and the time required for release is used, and the tolerance for delay of transmission data is used. By using different thresholds accordingly, it is possible to effectively prevent quality degradation and effectively use the bandwidth.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a block diagram of an optical system according to the present invention. Referring to FIG. 1, the optical system includes an OBS network 100, an OBS network 101, and a GMPLS optical network 200. The GMPLS optical network 200 connects the OBS network 100 and the OBS network 101, that is, the OBS network. Control packets and optical burst signals transmitted / received between 100 and the OBS network 101 are relayed.

  The GMPLS optical network 200 is a network including a plurality of GMPLS optical nodes 4, and sets a wavelength path as required by the GMPLS technology. In the following description, an optical network using the GMPLS technology will be described in the form of relaying between two OBS networks. However, the present invention may be a network that sets a wavelength path based on a request from each optical transmission apparatus. For example, it is not limited to the one using the GMPLS technology.

  The OBS networks 100 and 101 include a hybrid node 1, an OBS edge node 2, and an OBS core node 3.

  FIG. 3 is a block diagram of the OBS edge node 2 according to the present invention. According to FIG. 3, the OBS edge node 2 includes an input / output unit 21, a BCP transmission / reception unit 22, an optical burst signal processing unit 23, and an optical multiplexing / demultiplexing unit 24.

  For example, data received via the input / output unit 21 which is an interface with an information source such as another network such as an IP network or an image processing apparatus is input to the optical burst signal processing unit 23.

  The optical burst signal processing unit 23 generates the optical burst signal 6 from the input data. For example, when input data is a packet, even if one optical burst signal 6 is generated from one packet or a plurality of optical burst signals 6 are generated from one packet, a plurality of data belonging to the same communication is used. One optical burst signal 6 may be generated from the packets. When the input data is continuous data, the optical burst signal processing unit 23 divides the data into a predetermined length and generates a plurality of optical burst signals 6.

  Further, the optical burst signal processing unit 23 has a threshold value, and determines whether it is necessary to transmit the next optical burst signal 6 having the same destination as the generated optical burst signal 6 within or below the threshold value. Then, the BCP transceiver 22 is notified of the wavelength used for the generated optical burst signal 6, the destination of the data included in the optical burst signal 6, and the determination result based on the threshold. Thereafter, when a transmission instruction is received from the BCP transmission / reception unit 22, the optical burst signal 6 is transmitted to the OBS network via the optical multiplexing / demultiplexing unit 24, and the transmission completion is notified to the BCP transmission / reception unit 22.

  The BCP transmission / reception unit 22 includes a wavelength used for the optical burst signal 6 notified from the optical burst signal processing unit 23 and a destination of data included in the optical burst signal 6, and includes a predetermined wavelength including destination information and wavelength information of the optical burst signal. The control packet 5 is generated and transmitted to the OBS network via the optical multiplexing / demultiplexing unit 24. After a predetermined offset period has elapsed, the optical burst signal processing unit 23 is instructed to transmit the optical burst signal 6. When the transmission completion of the optical burst signal 6 is notified from the optical burst signal processing unit 23, the control packet 5 for releasing resources is transmitted to the OBS network via the optical multiplexing / demultiplexing unit 24.

  Here, the BCP transmitting / receiving unit 22 transmits the determination result based on the threshold in the optical burst signal processing unit 23, that is, the control packet 5 that transmits information indicating “transmit” or “not transmit” before and after the optical burst signal 6. Set either or both. As will be described later, for the hybrid node 1, the determination result included in the control packet 5 is that the wavelength path set in the GMPLS optical network 200 for transferring the control packet 5 and the optical burst signal 6 corresponding to the control packet 5. Is a command to maintain or cancel the wavelength path after transfer, “transmit” corresponds to “wavelength path maintenance”, and “not transmit” corresponds to “cancel wavelength path”.

  The OBS core node 3 has a routing table. When the control packet 5 is received, the OBS core node 3 transfers the control packet 5 based on the routing table and destination information included therein, and controls the optical burst signal 6 received after the offset period has elapsed. Transmit on the same route as packet 5. Thereafter, the control packet 5 indicating the resource release is also transferred to the same route.

  The hybrid node 1 is an optical communication device for interconnecting the OBS network 100 or 101 and the GMPLS optical network 200, and is installed at the boundary between the OBS network 100 or 101 and the GMPLS optical network 200.

  FIG. 2 is a block diagram of the hybrid node 1 according to the present invention. As shown in FIG. 2, the hybrid node 1 includes optical multiplexing / demultiplexing units 11 and 15, a BCP analysis unit 12, a GMPLS control unit 13, and a switching unit 14.

  The optical multiplexing / demultiplexing unit 11 outputs the control packet 5 received from the OBS network side to the BCP analyzing unit 12 and outputs the optical burst signal 6 to the switching unit 14.

  The BCP analysis unit 12 determines the transfer destination of the control packet 5 and the optical burst signal 6 from the destination information included in the control packet 5 based on the routing table, and the wavelength of the optical burst signal 6 included in the control packet 5 The optical burst signal 6 is recognized from the information. When the transfer destination of the control packet 5 and the optical burst signal 6 is the hybrid node 1 that interconnects the GMPLS optical network 200 and another OBS network, the destination information and the wavelength information are notified to the GMPLS control unit 13. .

  The GMPLS control unit 13 exchanges link information with the GMPLS optical node 4 in the GMPLS optical network 200 to recognize the network topology of the GMPLS optical network 200, and the destination information and wavelength information are notified from the BCP analysis unit 12. In this case, the GMPLS optical network is configured to set the wavelength path for the control packet 5 and the wavelength path for the optical burst signal 6 to the hybrid node 1 of another destination OBS network by the same route. 200 is instructed. More specifically, a wavelength path setting request message specifying a route is transmitted to the GMPLS optical network 200. However, as will be described later, when wavelength path maintenance is indicated in the control packet of the preceding optical burst signal 6 of the same destination, the wavelength path has already been set. Not performed.

  The switching unit 14 performs switching so that the optical burst signal 6 is output to an interface that accommodates the set wavelength path. After setting the wavelength path, the control packet 5 is transmitted to the GMPLS optical network 200 via the optical multiplexing / demultiplexing unit 15, and the optical burst signal 6 is transmitted via the optical multiplexing / demultiplexing unit 11, the switching unit 14, and the optical multiplexing / demultiplexing unit 15. , Transmitted to the GMPLS optical network 200.

  Subsequently, when the control packet 5 indicates wavelength path cancellation, the GMPLS control unit 13 transmits the optical burst signal 6 to the GMPLS optical network 200, and then cancels the wavelength path for the optical burst signal 6. After transmitting the control packet 5 for releasing resources to the GMPLS optical network 200, the wavelength path for the control packet 5 is released. On the other hand, when the wavelength path maintenance is indicated, the wavelength path is maintained without being released. The wavelength path maintained in this manner is maintained until the wavelength path release is indicated in the control packet 5 for the subsequent optical burst signal 6.

  In the present invention, the threshold value held by the OBS edge node 2 is the sum of the time required for wavelength path setting and the time required for cancellation in the GMPLS optical network 200, or a value near the sum obtained based on the sum. And

  As described above, the hybrid node 1 sets the wavelength path for the control packet 5 and the wavelength path for the optical burst signal 6 to the GMPLS optical network 200 through the same route, so that the control packet 5 and the optical burst signal are set. 6 order relation is guaranteed. Further, when the interval between the optical burst signals of the same destination is larger than the time required for releasing and resetting the wavelength path of the GMPLS optical network 200, the wavelength path is once released, so that the GMPLS optical network 200 is released. In the opposite case, the deterioration of quality such as delay of the optical burst signal to be transferred is prevented by maintaining the wavelength path.

  In the opposite hybrid node 1, the optical multiplexing / demultiplexing unit 15 outputs the control packet 5 received earlier to the BCP analyzing unit 12, and the BCP analyzing unit 12 outputs the optical multiplexing / demultiplexing corresponding to the interface to be output based on the destination information. The control packet 5 is output to the wave unit 11. The optical burst signal 6 and the control packet 5 received thereafter are output to the optical multiplexing / demultiplexing unit 11 corresponding to the same interface as the previous control packet 5 via the optical multiplexing unit 15, the switching unit 14 or the BCP analysis unit 12. .

  In the embodiment described above, the control packet 5 is transmitted before and after the optical burst signal 6. However, the control packet 5 is transmitted only before the optical burst signal 6, and the resource release is performed by the optical burst signal. The control packet 5 transmitted before 6 may be specified by time or the like. In this embodiment, when the control packet 5 indicates wavelength path cancellation, the wavelength path for the control packet 5 may be canceled after the control packet 5 transmitted before the optical burst signal 6 is transmitted to the wavelength path. .

  In the above-described embodiment, the setting of the wavelength path for the GMPLS optical network 200 is performed in units of destinations. Therefore, the maintenance of the wavelength path is determined based on the interval between the optical burst signals of the same destination. However, different wavelength paths may be set in the GMPLS optical network 200 for the same destination even if they are different communications. In this case, the wavelength is set at the interval between optical burst signals belonging to the same communication. Judge pass maintenance.

  Furthermore, when setting a wavelength path in units of optical burst signals belonging to the same communication, the transmission data delay tolerance is used in addition to the optical burst signal interval to determine whether or not to maintain the wavelength path. You can also. The delay tolerance of transmission data is determined in two steps, for example, high and low from information indicating an application, such as the port number of an IP packet, for example, and a threshold that differs depending on the delay tolerance, for example, transmission with a low delay tolerance As a threshold for data, a value smaller than the threshold for transmission data having a high delay tolerance is used. As a result, it is possible to suppress deterioration in the quality of data having a low delay tolerance.

It is a block diagram of the optical system by this invention. FIG. 3 is a block diagram of a hybrid node according to the present invention. FIG. 3 is a block diagram of an OBS edge node according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid node 2 OBS edge node 3 OBS core node 4 GMPLS optical node 5 Control packet 6 Optical burst signal 11, 15 Optical multiplexing / demultiplexing part 12 BCP analysis part 13 GMPLS control part 14 Switching part 21 Input / output part 22 BCP transmission / reception part 23 Optical burst Signal processing unit 24 Optical multiplexing / demultiplexing unit 100, 101 OBS network 200 GMPLS optical network

Claims (5)

In a system for interconnecting a first network that performs optical burst switching and a second network that sets a wavelength path,
A first device in the first network, connected to the first network and a second network, a system and a second apparatus for setting control of the wavelength path for the second network ,
The first device is
Means for generating an optical burst signal from transmission data;
Means for determining whether to maintain a wavelength path based on a time interval between the optical burst signal and a next optical burst signal belonging to the same destination or the same communication;
Means for generating a control packet of the optical burst signal, including a determination result of the determining means;
With
The second device is
Means for performing wavelength path setting control for the second network for setting the wavelength path;
The means for performing setting control uses the set wavelength according to the determination result included in the control packet when the wavelength path set in the second network is used to transfer the received control packet and the optical burst signal. Maintain or cancel a pass,
system. The determining means has a threshold value based on the sum of the time required for setting the wavelength path in the network and the time required for cancellation, and determines that the wavelength path is maintained when the time interval is less than the threshold value. ,
The system of claim 1. The means for determining classifies the transmission data according to the tolerance for the delay of the transmission data, and determines whether to maintain the wavelength path by applying different threshold values to each.
The system according to claim 2. A device in a first network in a system for interconnecting a first network that performs optical burst switching and a second network that sets a wavelength path,
Means for generating an optical burst signal from transmission data;
Based on the time interval between the optical burst signal and the next optical burst signal belonging to the same destination or the same communication, when the optical burst signal passes through a second network for setting a wavelength path, the optical burst signal is Means for determining whether or not to maintain the relayed wavelength path after relaying;
Means for generating a control packet of the optical burst signal, including a determination result of the determining means;
A device equipped with. A method of relaying data transmitted from a first network performing optical burst switching to a third network performing optical burst switching through a second network for setting a wavelength path,
Generating an optical burst signal from transmission data in a first device in a first network;
In the first device, determining whether to maintain a wavelength path based on a time interval between the optical burst signal and the next optical burst signal belonging to the same destination or the same communication;
Generating a control packet of the optical burst signal including a determination result in the determining step in the first device;
A second device that is connected to the first network and the second network and controls the setting of the wavelength path for the second network is between an interconnect device between the second network and the third network. Transmitting the control packet and the optical burst signal to the wavelength path set in
A second device maintaining or releasing the set wavelength path according to a determination result included in the control packet;
A method comprising:

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