JP5827175B2 - Optical switching network data transfer method, optical switching network control device, and node device - Google Patents

Description

  The present invention relates to an optical switching network such as a network that performs optical burst switching, and more particularly to a data transfer technique in an optical switching network.

  Non-Patent Document 1 discloses application of an open flow (OpenFlow) technique to a WSON (Wavelength Switched Optical Network) which is a network for setting a wavelength path. Here, as described in Non-Patent Document 1, the open flow technology refers to a network technology in which a node device that performs packet routing or switching and a control device that determines a packet route are separated. In the OpenFlow network, a flow is, for example, a VLAN (Virtual LAN) ID, a layer 2 source address such as Ethernet (registered trademark), a layer 2 destination address, or a layer 3 source address such as IP. , Layer 3 destination address, layer 4 source port number such as TCP, layer 4 destination port number, or any combination thereof.

  The node device holds a flow table indicating the relationship between the flow and the physical port that is the output destination of the packet belonging to the flow. When the node device receives the packet, the node device assigns the packet to the physical port determined based on the flow table. Is output. Here, when the node device receives a packet that does not belong to any flow shown in the flow table, the node device transmits the received packet to the control device. The control device holds information regarding the connection relationship between each node device of the OpenFlow network and the connection relationship. The control device determines the flow route to which the packet belongs based on the received packet, and the packet is transferred along the determined route. As shown, the flow table of the related node device is updated. That is, the node device is notified of the relationship between the flow to which the received packet belongs and the physical port that is the output destination of the packet belonging to the flow.

  In Non-Patent Document 1, for application to a wavelength path, the path of each flow is determined by an optical ADM (Add-Drop MUX) or a wavelength path which is a unit of connection in a wavelength cross-connect device, and the determined path A wavelength path is set.

  In addition, as described in Non-Patent Document 2, when there is data to be transmitted at present, a wavelength in the data is allocated for a time required for transmission of the data, and the data is allocated to the allocated wavelength. An optical burst switching (OBS) network that transmits as an optical burst signal is proposed.

Lei Liu, et al. , "OpenFlow-based Wavelength Path Control in Transparent Optical Networks: a Proof-of-Concept Demonstration," ECOC 2011 September 2011 Lei Liu, et al. , "Dynamic provisioning of self-organized consumer grid services over integrated OBS / WSON networks," IEEE / OSA Journal of Light 12 months.

  According to Non-Patent Document 2, a control device for WSON and a control device for OBS network according to GMPLS (Generalized Multi-Protocol Label Switching) technology are separately provided for mutual connection between WSON and OBS network.

  The present invention provides a data transfer method in an optical switching network capable of determining a path and transferring data with a simpler configuration than the prior art, and a control device and a node device for the optical switching network.

  According to one aspect of the present invention, there is provided a data transfer method in a system including a plurality of node devices and relaying data, and a control device, wherein the optical switching network receives the relayed data The first node device transmits a request signal including information indicating the destination of the data to the control device, the control device determines a relay route of the data, and the control device includes: Transmitting a setting signal including information indicating an input port and an output port to each of the second node devices other than the first node device on the relay path; and each of the second node devices The first wavelength signal input to the input port indicated by the setting signal is set to be output from the output port indicated by the setting signal. Transmitting a completion signal to the control device; when the control device receives the completion signal from all of the second node devices; a second wavelength different from the first wavelength; an output port; And a control packet including information indicating a destination of the data when the first node device receives the start signal from the control device. Is transmitted from the output port indicated by the start signal at the first wavelength, and after a predetermined time from the transmission of the control packet, the data is transmitted from the output port indicated by the start signal to the second wavelength. And transmitting.

  Further, according to one aspect of the present invention, a node device of the optical switching network in a system having an optical switching network for relaying data and a control device, and receiving the data to be relayed, the destination of the data And a second wavelength different from the first wavelength used for the control packet as a response to the request signal from the control device, and an output. When a start signal including information indicating a port is received, a control packet including information indicating a destination of the data is transmitted from the output port indicated by the start signal at the first wavelength, and the control packet is transmitted. And a second means for transmitting the data at the second wavelength from the output port indicated by the start signal after a predetermined time from That.

  Further, according to one aspect of the present invention, the control apparatus of the optical switching network includes a plurality of node devices and relays data, from the first node device of the optical switching network that has received the data to be relayed, When a request signal including information indicating the destination of the data is received, a first means for determining a relay route of the data and a second node device other than the first node device on the relay route And a second wavelength for transmitting a setting signal including information indicating an input port and an output port, and a first wavelength input to the input port indicated by the setting signal from all of the second node devices. Information indicating the second wavelength different from the first wavelength and the output port when receiving a completion signal indicating that the setting of outputting the signal from the output port indicated by the setting signal has been performed A third means for transmitting to said first node apparatus a start signal containing, characterized in that it comprises.

  The control device determines a path and performs at least setting for exchanging control packets with the second node device. Thereafter, the first node device starts data transmission by notifying the first node device of the wavelength used for data and its output port. With the above configuration, it is possible to determine the route and perform data transfer with a simpler configuration as compared with the conventional configuration.

1 is a schematic configuration diagram of an optical switching network according to an embodiment. FIG. The sequence diagram of the data transfer by one Embodiment. 1 is a schematic configuration diagram of an edge node that performs optical burst switching according to an embodiment. FIG. 1 is a schematic configuration diagram of a core node that performs optical burst switching according to an embodiment. FIG.

  (First Embodiment) FIG. 1 is a schematic configuration diagram of an exemplary optical communication system in the present embodiment. In the following drawings, components that are not necessary for understanding the embodiment are omitted from the drawings for simplification. In FIG. 1, optical burst switching (OBS) networks 1 and 2 are both connected to WSON 3, which is a wavelength switching network for setting a wavelength path. A control device 4 is provided to control the OBS networks 1 and 2 and each node device of the WSON 3.

  Here, the WSON 3 is a network for setting and releasing a wavelength path under the control of the control device 4, and is configured by, for example, an optical cross-connect device, a wavelength cross-connect device, or the like. On the other hand, the OBS networks 1 and 2 are networks that perform optical burst switching, and include an edge node (EN) and a core node (CN). For example, in FIG. 1, EN11 and CN12 of the OBS network 1 and EN21 and CN22 of the OBS network 2 are shown. For the purpose of explanation, EN and CN are distinguished, but EN and CN can be the same device. That is, for example, a configuration in which EN11 is directly connected to WSON3 may be employed.

  For example, the OBS networks 1 and 2 and the WSON 3 relay data, that is, IP packets for an IP network (not shown). Specifically, EN11 and 21 are connected to an IP network or the like (not shown), and when EN11 receives an IP packet transmitted from the connected IP network to the IP network connected to EN21, EN11 The received IP packet is converted into an optical burst signal and transmitted to EN21. Prior to transmission of the optical burst signal, ENs 11 and 21 generate a control packet called BHP (Burst Header Packet) and transmit the optical burst signal at the wavelength assigned to the control packet. Send. The control packet includes destination information of the optical burst signal and wavelength information used by the optical burst signal. Each node of the OBS networks 1 and 2 first receives a control packet, and based on this control packet, determines the wavelength used by the subsequent optical burst signal and exchanges the optical burst signal.

  Further, CN11 and CN21 are devices that are connected to both the WSON 3 and the OBS network and serve as terminal points of wavelength paths set by the WSON 3, and function as relay devices between the WSON 3 and the OBS network. A plurality of core nodes may exist between EN11 and CN12 or between EN21 and CN22.

  Hereinafter, when the EN 11 in FIG. 1 receives an IP packet to be transmitted to the IP network connected to the EN 21, data transfer of the IP packet will be described with reference to FIG. It is assumed that the control device 4 in FIG. 1 holds information on the functions of OBS networks 1 and 2 and the node devices of the WSON 3, the connection relationship, and the current usage status of each optical link. That is, when a data transmission source and transmission destination node device are given, it is possible to determine the data transfer path and the wavelength to be used.

  When the EN 11 receives an IP packet to be transmitted to the IP network connected to the EN 21 in S 1, the EN 11 transmits a request signal to the control device 4 in S 2. The request signal includes information indicating a destination for specifying a flow, for example, a transmission destination address, a transmission source address, a transmission destination port number of TCP, a transmission source port number, and the like.

  When the control device 4 receives the request signal, in S3, it determines the transfer path of the flow, the first wavelength for the control packet, and the second wavelength for the optical burst signal from the information included in the request signal. Shall be determined. The path for the control packet and the path for the optical burst signal are the same in WSON 3 as well. Here, in this example, it is assumed that the route reaching EN21 via CN12, WSON3, and CN22 of FIG. 1 is determined.

  The control device 4 transmits a setting signal in S4 to each node device on the route determined in S3 except for EN11. 1 and 2 do not show individual devices in the WSON 3 for simplification, but the actual device in the WSON 3 for setting the wavelength path connecting the CN 12 and the CN 22 is actually used. A setting signal is transmitted to each device. The setting signal notified to each node device of the OBS networks 1 and 2 includes information indicating the input optical port, the output optical port, and the first wavelength for the control packet. The setting signal notified to each device in the WSON 3 includes information indicating the first wavelength for the control packet, the second wavelength for the optical burst signal, and their input ports and output ports. . The control packet and the optical burst signal input port and output port are the same.

  In S4, each node device that has received the setting signal performs setting for exchanging or connecting the designated optical wavelength between the designated optical ports, and transmits a completion signal to the control device 4 when the setting is completed. Specifically, each node device of the OBS networks 1 and 2 performs setting to output an optical signal of the first wavelength received at the input port specified by the setting signal from the output port specified by the setting signal. A completion signal is transmitted to the control device 4. Each node of the WSON 3 transmits a completion signal to the control device 4 when it is set to exchange the wavelength path of the first wavelength and the wavelength path of the second wavelength between the designated input port and output port. When receiving the completion signal from all the node devices that have notified the setting signal (S5), the control device 4 transmits a start signal to the EN 11 that has transmitted the request message in S6.

  Here, the start signal transmitted to EN11 includes information indicating the optical port that outputs the control packet and the optical burst signal, and the first wavelength and the second wavelength used for the control packet and the optical burst signal, respectively. It is out. When receiving the start signal, EN11 starts the transmission process in S7 using the start signal as a trigger. Specifically, first, based on the received start signal, a control packet including information indicating the second wavelength used by the optical burst signal is generated, and the generated control packet is set to the first signal specified by the start signal. It converts to an optical signal of wavelength and outputs it to the optical port specified by the start signal. After that, an optical burst signal of the second wavelength specified by the start signal is generated from the received IP packet, and when a predetermined time elapses after transmission of the control packet, the generated optical burst signal is specified by the start signal. Output to the optical port.

  The CN 12 first receives the control packet signal of the first wavelength from the EN 11, but the CN 12 divides this optical signal, for example, into two, and outputs one optical signal as it is to the designated output port, The other optical signal is converted into an electrical signal, and wavelength information of the optical burst signal indicated by the control packet signal, that is, the second wavelength is acquired. After that, the CN 12 performs a second wavelength connection from the input port to the output port of the control packet signal. Thereby, the optical burst signal from EN11 is output to the optical port following the path determined by the control device 4.

  In WSON 3, the first wavelength path for the control packet and the second wavelength path for the optical burst signal are set on the same route, and the control packet and the optical burst signal are respectively transferred through dedicated wavelength paths. The After that, in the CN 22, as described with the CN 12, the control packet and the optical burst signal are transferred, and the control packet and the optical burst signal reach EN21 in S8. The EN 21 generates an IP packet from the received optical burst signal and transmits it to the IP network connected to the EN 21.

  When the EN 21 receives the optical burst signal, it transmits a reception completion signal to the control device 4 in S9. When the control device 4 receives the reception completion signal, the control device 4 transmits a setting release message to each node device in the path in S10. Thus, each device in the path releases the wavelength path setting.

  FIG. 3 is a block diagram showing the configuration of EN11. The configuration of EN21 is the same. The signal processing unit 111 is connected to the IP network, generates an optical burst signal from an IP packet received from the IP network, generates an IP packet from the optical burst signal received from the optical SW unit 112, and transmits the IP packet to the IP network. Perform the process. The optical SW unit 112 sets a wavelength path according to an instruction from the flow table processing unit 113. In addition, the flow table processing unit 113 performs communication processing with the control device 4 and management of a flow table indicating the wavelength path setting state in the optical SW unit 112. Further, the control packet processing unit 114 performs control packet generation and optical signal conversion processing.

  For example, when the signal processing unit 111 receives one or more IP packets belonging to a new flow, the flow table processing unit 113 notifies the flow table processing unit of information such as addresses obtained from these IP packets. Transmits a request signal to the control device 4. When the flow table processing unit 113 receives a start signal as a response to the request signal from the control device 4, the flow table processing unit 113 outputs the start signal to the control packet processing unit 114, and the signal processing unit 111 uses the second signal to be used for the optical burst signal. Notify the wavelength of. Further, the flow table processing unit 113 controls the optical SW unit 112 so that the control packet generated by the control packet processing unit 114 is output to the optical port notified by the start signal. The optical SW unit 112 is controlled so that the optical burst signal generated by the processing unit 111 is output.

  The control packet processing unit 114 generates a control packet including information indicating the second wavelength used by the optical burst signal, notified by the start signal, and generates the generated control packet by using the first signal specified by the start signal. The optical signal is converted into an optical signal having a wavelength and output to the optical SW unit 112. The output to the optical SW unit 112 is performed after the flow table processing unit 113 performs setting for the optical SW unit 112 to output the control packet to the target optical port. The optical burst signal processing unit 111 converts one or more received IP packets into an optical burst signal of the second wavelength notified from the flow table processing unit 113, and transmits a control packet for a predetermined period. Is transmitted to the optical SW unit 112.

  FIG. 4 is a block diagram showing the configuration of the CN 12. When the flow table processing unit 123 receives the setting signal from the control device 4, the flow table processing unit 123 adds the relationship between the input port, the output port, and the first wavelength specified by the setting signal to the flow table, and performs light transmission according to the added information. The first wavelength connection between the input port and the output port of the SW unit 122 is performed. Further, when the optical SW unit 122 receives the control packet of the first wavelength at the input port, the optical SW unit 122 outputs the control packet from the designated optical port and simultaneously outputs it to the control packet processing unit 121. The control packet processing unit 121 connects the second wavelength indicated by the control packet between the input port and the output port of the control packet, thereby transferring the optical burst signal.

  In the above embodiment, the control device 4 determines the first wavelength used for the control packet. However, the first wavelength can be determined in advance by the system and not notified in each process. In the above embodiment, the control device 4 does not include the second wavelength in the setting signal. Therefore, each node device analyzes the control packet and determines the second wavelength. However, the second wavelength may be included in the setting signal, and each node device may be configured to connect the second wavelength based on the setting signal. In this case, each node device in the OBS network does not need to analyze the control packet. However, even in this case, for interconnection with the conventional optical burst switching network, it is necessary to transfer the destination information and the control packet indicating the second wavelength through the same path prior to the optical burst signal. Further, in the above embodiment, the node devices in the OBS networks 1 and 2 also wait for the setting release signal from the control device 4 and release the connection of the first wavelength and the second wavelength. However, the node devices in the OBS networks 1 and 2 do not wait for the setting release signal from the control device 4 and immediately transfer the control packet and the optical burst signal, so that the connection of the first wavelength or the second wavelength is immediately performed. It is also possible to adopt a configuration in which Furthermore, the above embodiment has a configuration in which the WSON 3 connects the OBS networks 1 and 2. However, the present invention can also be applied to data transfer only within the OBS networks 1 and 2. In the above-described embodiment, the optical switching system has been described by optical burst switching. However, the present invention can also be applied to optical flow switching. That is, the optical switching network includes optical burst switching and optical flow switching.

Claims (14)

A data transfer method in a system including a plurality of node devices, an optical switching network for relaying data, and a control device,
The first node device of the optical switching network that has received the data to be relayed transmits a request signal including information indicating a destination of the data to the control device;
The control device determining a relay route of the data;
The control device transmitting a setting signal including information indicating an input port and an output port to each of the second node devices other than the first node device on the relay path;
Each of the second node devices performs setting to output a signal of the first wavelength input to the input port indicated by the setting signal from the output port indicated by the setting signal, and the control device Sending a completion signal to
When the control device receives the completion signal from all of the second node devices, a start signal including information indicating a second wavelength different from the first wavelength and an output port is generated. Transmitting to the node device of
When the first node device receives the start signal from the control device, a control packet including information indicating a destination of the data is transmitted from the output port indicated by the start signal at the first wavelength, Transmitting the data at the second wavelength from the output port indicated by the start signal after a predetermined time from transmission of the control packet;
A method comprising the steps of: The first wavelength is a predetermined wavelength.
The method according to claim 1. The control device determines the first wavelength, notifies the first wavelength to the second node device with the setting signal, and sends the first wavelength to the first node device with the start signal. Notice,
The method according to claim 1. The second node device at the end of the relay path transmits a reception completion signal to the control device after receiving the data,
When the control device receives the reception completion signal, the control device outputs a release signal that causes each of the second node devices to release the setting of outputting the signal of the first wavelength from the output port indicated by the setting signal. Send,
The method according to any one of claims 1 to 3, characterized in that: The first node device includes information indicating the second wavelength in the control packet,
Each of the second node devices determines the second wavelength used in the data received after receiving the control packet from the information included in the control packet, and sets the data Output from the output port indicated by the signal,
The method according to any one of claims 1 to 4, characterized in that: The control device includes information indicating the second wavelength in the setting signal,
Each of the second node devices performs setting to output the signal of the second wavelength input to the input port indicated by the setting signal from the output port indicated by the setting signal, and performs the control Sending the completion signal to the device;
The method according to any one of claims 1 to 4, characterized in that: The system includes a first optical switching network, a second optical switching network, and a wavelength switching network that relays between the first optical switching network and the second optical switching network;
When the data relay path is from the first optical switching network to the second optical switching network via the wavelength switching network, the control device is configured to transmit the wavelength on the relay path. A third node device connected to both the switched network and the first optical switched network; a fourth node device connected to both the wavelength switched network and the second optical switched network on the relay path; The wavelength switching network apparatus is controlled so that the wavelength path of the first wavelength and the wavelength path of the second wavelength are set in the same path during
A method according to any one of claims 1 to 6, characterized in that A node device of the optical switching network in a system having an optical switching network for relaying data and a control device,
Receiving the data to be relayed, a first means for transmitting a request signal including information indicating a destination of the data to the control device;
When a start signal including information indicating a second wavelength different from the first wavelength used for the control packet and an output port is received as a response to the request signal from the control device, information indicating the destination of the data A control packet including the first packet from the output port indicated by the start signal, and after a predetermined time from the transmission of the control packet, the data is transmitted from the output port indicated by the start signal. A second means for transmitting at the second wavelength;
A node device comprising: The second means includes the information indicating the second wavelength in the control packet in order to notify the node device on the data relay path of the second wavelength used for the data transmission.
The node device according to claim 8, wherein: When a setting signal including information indicating an input port and an output port is received from the control device, the signal of the first wavelength input to the input port indicated by the setting signal is output by the setting signal. And a third means for transmitting a completion signal to the control device.
The node device according to claim 8 or 9, characterized by the above. The setting signal includes information indicating the second wavelength,
The third means performs setting to output the signal of the second wavelength input to the input port indicated by the setting signal from the output port indicated by the setting signal, and causes the control device to Send a completion signal,
The node device according to claim 10. A control apparatus for an optical switching network that includes a plurality of node devices and relays data,
Receiving a request signal including information indicating a destination of the data from a first node device of the optical switching network that has received the data to be relayed, a first means for determining a relay route of the data;
Second means for transmitting a setting signal including information indicating an input port and an output port to each of the second node devices other than the first node device on the relay path;
A completion signal indicating that setting has been performed so that the first wavelength signal input to the input port indicated by the setting signal is output from the output port indicated by the setting signal from all of the second node devices. , A third means for transmitting to the first node device a start signal including information indicating a second wavelength different from the first wavelength and an output port;
A control device comprising: Further comprising means for determining the first wavelength;
The second means notifies the second node device of the first wavelength by the setting signal;
The third means notifies the first node device of the first wavelength by the start signal;
The control device according to claim 12. The system includes a first optical switching network, a second optical switching network, and a wavelength switching network that relays between the first optical switching network and the second optical switching network;
When the data relay path is from the first optical switching network to the second optical switching network via the wavelength switching network, the control device, the wavelength on the relay path A third node device connected to both the switched network and the first optical burst switched network, and a fourth node device connected to both the wavelength switched network and the second optical switched network on the relay path The wavelength switching network apparatus is controlled so that the wavelength path of the first wavelength and the wavelength path of the second wavelength are set in the same path between
The control device according to claim 12 or 13,

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