JP4564389B2 - Optical routing apparatus and optical routing method - Google Patents

Description

  The present invention relates to an optical routing apparatus and an optical routing method for switching an optical signal transfer path between input and output ports, and more particularly to an optical routing apparatus and an optical routing method capable of switching a large number of output ports at high speed.

  In order to transmit a large amount of information, wavelength division multiplexing (WDM) technology or optical time division multiplexing (OTDM) technology is used. On the other hand, in addition to these technologies, in order to realize optical signal transfer processing with finer time granularity, optical routing that assigns labels including destination information to intermittent optical signals and switches paths based on the labels Technology is being considered. This optical routing device is configured to determine the transfer destination of an optical signal based on destination information included in a label attached to an optical signal input intermittently and to switch the path of the optical switch (for example, the following patent) Reference 1 and non-patent reference 2).

JP 2003-110504 A Y. Chen, et.al., "Optical Burst Switching (OBS): A New Area in Optical Networking, IBS". Triple Network (IEEE Network), vol. 18, pp. 16-23, May, 2004

  However, in the conventional optical routing device, in order to read the destination information included in the label attached to the optical signal input intermittently, the input optical signal and the label receiving unit are received at the label receiving unit of the optical routing device. It is necessary to synchronize the clock frequency and phase, and the time required for this synchronization hinders the speeding up of the transfer processing speed and path switching speed in the routing device. In particular, there has been a demand for a technique in which a plurality of destinations are set for an optical signal, and an optical routing device can switch a plurality of routes (a plurality of output ports, for example, eight ports) at high speed corresponding to the plurality of destinations.

  An object of the present invention is to provide an optical routing device and an optical routing method capable of recognizing a plurality of pieces of destination information at high speed and quickly selecting a route corresponding to the destination information in order to solve the above-described problems caused by the prior art. And

In order to solve the above-described problems and achieve the object, the optical routing device according to the first aspect of the present invention receives an optical burst signal to which a label including destination information is added at the temporal head portion of the intermittent optical signal. In the optical routing device for transferring the optical burst signal to the path corresponding to the destination information for each burst, label detection means for detecting identification information of the input start of the label of the optical burst signal, and the label of the optical burst signal Destination information acquisition means for acquiring the destination information included in the information, branch means for branching and simultaneously inputting the optical burst signal to the label detection means and the destination information acquisition means, and the label detection means It triggered by detection of the identification information, while the destination information obtaining means is maintained for a predetermined period the destination information, the destination information of the optical burst signal A plurality of corresponding destination information candidates are sequentially compared with the destination information, and the destination information matching judgment means for judging the matching between the destination information match judgment means and the destination information matching judgment means when the judgment results match, the forwarding destination indicated by the destination information And a path setting means for setting the path of the inputted optical burst signal.

  An optical routing device according to a second aspect of the present invention is the optical routing device according to the first aspect, wherein destination information acquisition means for acquiring the destination information included in a label of the optical burst signal, and the plurality of destination information candidates Preregistered destination information candidate registration means, trigger output means for outputting a trigger for requesting output of a plurality of destination information candidates upon detection of the identification information by the label detection means, and trigger by the trigger output means Reading means for reading the plurality of destination information candidates registered in the destination information candidate registration means in a predetermined order based on the output of the destination information and outputting the candidates to the destination information match judgment means. It is characterized by.

  According to a third aspect of the present invention, there is provided the optical routing device according to the second aspect of the present invention, wherein the matching information processing by the destination information matching judgment unit and the reading processing of the destination information candidate by the reading unit are performed simultaneously. It is characterized by being performed in parallel and asynchronous to each other.

  An optical routing device according to a fourth aspect of the present invention is the optical routing apparatus according to the second aspect, wherein the destination information match determination means includes a data string of the destination information and a data string of the destination information candidates sequentially input. Is determined in bit units.

  An optical routing device according to a fifth aspect of the present invention is the optical routing apparatus according to the second aspect, wherein the reading means is registered in the destination information candidate registration means by the output of the trigger by the trigger output means. The destination information candidates are read from the beginning, from the end, or randomly.

  An optical routing device according to a sixth aspect of the present invention is the optical routing device according to any one of the first to fifth aspects, wherein the route setting means is configured to correspond to a route indicated by the destination information candidate. One of the plurality of output ports is selected, and the optical burst signal input to the input port is output from the selected output port.

  According to a seventh aspect of the present invention, in the optical routing device according to the sixth aspect of the present invention, the optical burst signal is branched and input to the label detecting means and the optical switch.

In the optical routing method according to the eighth aspect of the present invention, an optical burst signal including destination information of the signal is input to the label of the burst signal, and the optical burst signal is transferred to a path corresponding to the destination information for each burst. In the optical routing method, a label detection step of detecting input start identification information of the label of the optical burst signal, a destination information acquisition step of acquiring the destination information included in a label of the optical burst signal, and the optical burst triggered a branch step for branching the signal to perform the processing of the destination information obtaining step and the processing of the label detection step simultaneously, the detection of the identification information by the label detection step, the destination information obtaining step during a certain period of time retaining the address information sequentially said addressed plurality of destination information candidate corresponding to the destination information of the optical burst signal When the destination information match determination step for comparing the information with each other and the determination result by the destination information match determination step match, the input light is inputted so as to correspond to the transfer destination indicated by the destination information candidate And a path setting step for setting the path of the burst signal.

  According to the optical routing device and the optical routing method of the present invention, it is possible to quickly determine the transfer destination of an optical burst signal having a plurality of destination candidates, and it is possible to quickly select a route corresponding to the destination information. There is an effect. Furthermore, since the route setting is speeded up, when an optical switch having a high switching speed is used, the high speed can be fully utilized.

  Exemplary embodiments of an optical routing device and an optical routing method according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing an optical routing device according to the present invention. The optical routing device 100 includes a label recognition unit 101, a switch control unit 102, and an optical switch 103.

  The optical signal 110 input via the transmission path is made into a burst, and a label 110a made up of destination information is attached to the head of the optical signal 110 in units of bursts. The optical signal 110 may be either a fixed-length burst or a variable-length burst, and an arbitrary burst length can be set. The optical signal 110 is branched by a branching unit 105 such as an optical coupler and the like, and is input to the label recognition unit 101 and the optical switch 103, respectively.

  The optical burst signal is a variable-length intermittent optical signal in which a packet including destination information is added to a group of packets that are directed to the same destination, and is used as one transfer processing unit. The optical signal 110 used in the following description refers to this optical burst signal. The optical routing device and the optical routing method of the present invention can be applied to an intermittent optical signal of any length with a label including destination information at the beginning of time, and generate an optical burst signal. An optical packet signal as a unit can be handled in the same manner.

  The label recognition unit 101 exchanges information related to label recognition (a trigger signal S1, a destination information candidate S2, and a match flag S3, which will be described later) with the switch control unit 102 in order to recognize the label 110a of the input optical signal 110. Then, the destination information set in the label 110a of the optical signal 110 is recognized.

  When a process related to label recognition is requested from the label recognition unit 101, the switch control unit 102 reads a plurality of output port switching destinations set in advance corresponding to the destination information indicated by the label 110a of the optical signal 110. Information regarding the read output port (trigger signal S1, destination information candidate S2, and match flag S3, which will be described later) is sequentially exchanged with the label recognition unit 101. When the label recognition unit 101 obtains information with matching destination information, a signal for switching the switch of the optical switch 103 and selecting an output port (switch control described later) is performed in order to perform optical routing corresponding to the destination information. The signal S4) is output.

  The processing performed on the label recognition unit 101 side and the processing performed on the switch control unit 102 side are performed independently (asynchronously). The switch control unit 102 executes processing related to reading regardless of the processing procedure and processing speed of the label recognition unit 101 based on a request for processing related to label recognition (when a trigger signal S1 described later is input) from the label recognition unit 101. To do.

  The optical switch 103 has one input port and a plurality of n (eight in this embodiment) output ports. The optical signal 110 input to the input port is controlled by the switch control unit 102 to switch the switch, and is output from the output port set corresponding to the destination information indicated by the label 110a of the optical signal 110. The output port is switched by a drive unit (not shown).

  In the configuration illustrated in FIG. 1, the label recognition unit 101 and the switch control unit 102 are described as separate configurations. The label recognizing unit 101 executes only processing related to the recognition of the label 110a. On the other hand, the switch control unit 102 includes an FPGA or the like, and operates with a different operation clock regardless of the operation clock of the label recognition unit 101. By setting the operation clock of the switch control unit 102 at a higher speed than the operation clock of the label recognition unit 101, the switch control unit 102 sends the destination candidate information S2 to the label recognition unit 101 as soon as possible. It becomes possible to output.

  Next, the configuration of each part of the optical routing device shown in FIG. 1 will be described in detail.

  FIG. 2 is a block diagram showing the internal configuration of the label recognition unit. The label recognition unit 101 includes a signal input unit 201, a label detection unit 202, a trigger output unit 203, a destination information acquisition unit 204, a destination information match determination unit 205, a destination information candidate input unit 206, and a match flag output. Unit 207.

  The signal input unit 201 includes an O / E conversion unit (not shown), converts the input optical signal 110 into an electrical signal, and outputs the electrical signal. The label detection unit 202 detects the input of the label 110 a of the optical signal 110 output from the signal input unit 201. Specifically, when a predetermined identifier such as a delimiter set at the head of the data string constituting the label 110a of the optical signal 110 is input, it is detected as the input of the label 110a, and the trigger output unit 203 triggers that the detection is immediately performed. The signal S1 is output to the switch control unit 102.

The destination information acquisition unit 204 holds the destination information included in the label 110a of the optical signal 110 output from the signal input unit 201 for a predetermined time at a predetermined timing using a latch circuit (not shown). Here, in the label detection unit 202, the trigger information S1 is output at a timing before the destination information acquisition unit 204 holds the destination information included in the label 110a, and the read processing by the switch control unit 102 is started.

  The destination information match determination unit 205 includes the destination information of the label 110 a acquired by the destination information acquisition unit 204, and the destination information candidate S 2 output from the switch control unit 102 and input via the destination information candidate input unit 206. Is entered to determine the match. When they match, the match flag S3 is output to the switch control unit 102 via the match flag output unit 207. The destination information and the destination information candidate S2 are composed of the same data string, and the presence or absence of matching can be easily determined by bit determination described later.

  FIG. 3 is a block diagram illustrating an internal configuration of the switch control unit. The switch control unit 102 includes a trigger input unit 301, a table reading unit 302, a routing table 303, a destination information candidate output unit 304, a match flag input unit 305, a destination information candidate holding unit 306, and a switch control signal output. Part 307.

  The trigger input unit 301 receives the trigger signal S1 output from the trigger output unit 203 of the label recognition unit 101. The table reading unit 302 starts reading (reading) the destination information candidate S2 stored in the routing table 303 at the timing when the trigger signal S1 is input. This reading can be performed by setting a search key, but in this embodiment, the search key is not set, and the destination information candidate S2 is read in the order of addresses stored in the routing table 303. Process. The read destination information candidate S2 is output to the label recognition unit 101 via the destination information candidate output unit 304.

  The destination information candidate holding unit 306 holds the destination information candidate S2 read by the table reading unit 302. The match flag S3 output from the label recognition unit 101 is input to the destination information candidate holding unit 306 via the match flag input unit 305. The destination information candidate holding unit 306 holds the destination information candidate S2 until the match flag S3 is input during a predetermined cycle. Therefore, the destination information candidate S2 held by the destination information candidate holding unit 306 when the match flag S3 is input is output to the switch control signal output unit 307. On the other hand, when the match flag S3 is not input during a predetermined cycle, the destination information candidate S2 held in the destination information candidate holding unit 306 until then is canceled, and the destination information candidate S2 read by the table reading unit 302 is then released. Is newly held.

  The predetermined cycle held by the destination information candidate holding unit 306 is, for example, one clock cycle, and is a cycle in which the table reading unit 302 reads one destination information candidate S2 from the routing table 303.

  The switch control signal output unit 307 outputs a switch control signal S4 for selecting an output port of the optical switch 103 to the optical switch 103 based on the input destination information candidate S2.

  The optical switch 103 can be configured by a general-purpose optical switch. The optical switch 103 switches an internal switch in response to the switch control signal S4. By this switch switching, the optical signal 110 (see FIG. 1) input to the input port can be selectively output from one output port (one of 1 to n) indicated by the switch control signal S4, and routing is performed. The function can be realized.

  The routing table 303 shown in FIG. 3 has a function as a destination information candidate registration unit in which a plurality of destination information candidates S2 are registered in advance. Further, the table reading unit 302 reads a plurality of destination information candidates S2 registered in the routing table 303 in a predetermined order, and these destination information candidates S2 are output to the destination information candidate output unit 304 and the destination information candidate input unit. It has a function as a reading unit that outputs to the destination information match determination unit 205 via 206 (see FIG. 2). The switch control signal output unit 307 has a function as a path setting unit that sets the path of the input optical signal 110.

  FIG. 4 is a chart showing a routing table. The routing table 303 is a setting table that is referred to for connection (optical path switching) between one input port of the optical switch 103 and a plurality of n (n = 8) output ports. As shown in FIG. 4, the routing table 303 includes the contents of the destination information candidate S <b> 2 referred to corresponding to the destination information of the input optical signal 110, that is, the input port corresponding to the destination information of the optical signal 110. Output port relationship is set.

  For example, if the destination information indicated by the label 110a of the optical signal 110 is “0001”, the output port is switched to “1”. If the destination information is “0008”, the output port is switched to “8”. The destination information candidate S2 set in the routing table 303 is used for reference when comparing with the destination information indicated by the label 110a of the optical signal 110 input to the optical switch 103. Therefore, when the destination information candidate S2 set in the routing table 303 matches the destination information indicated by the label 110a of the optical signal 110, the output port indicated by the destination information candidate S2 set in the routing table 303 is selected. That's fine. The destination information and the destination information candidate S2 are composed of, for example, a 4-bit xxx data string, and can be determined to match at high speed in bit units.

  The table reading unit 302 (see FIG. 3) sequentially reads the destination information candidate S2 set in the routing table 303 according to the input of the trigger signal S1 according to a predetermined procedure. In the example illustrated in FIG. 4, eight destination information candidates S2 that are the number of output ports are sequentially read, and the destination information candidate S2 is output to the label recognition unit 101 each time it is read. For example, the destination information candidate S2 or the output port number can be read out in ascending order or descending order. Alternatively, the destination information candidates S2 for the eight output ports may be read randomly for each cycle in units of one cycle.

  Next, the operation of the optical routing device 100 configured as described above will be described with reference to FIGS.

  FIG. 5 is a flowchart showing the operation content of the label recognition unit. The label recognition process executed by the label recognition unit 101 is described as step S500. First, the optical signal 110 is input to the signal input unit 201 of the label recognition unit 101 (step S501). The label detection unit 202 waits for detection of predetermined identification information located at the head of the destination information described in the label 110a of the optical signal 110 (step S502: No loop). As the identification information, for example, a predetermined code such as a delimiter indicating the start of input of the destination information can be used.

  When the label detection unit 202 detects the identification information by the delimiter (step S502: Yes), since the input of the identification information is started, the trigger detection unit 203 outputs the trigger signal S1 (step S503). The trigger signal S1 is input to the trigger input unit 301 of the switch control unit 102. As will be described later, the switch control unit 102 immediately starts reading the destination information candidate S2 stored in the routing table 303 in response to the input of the trigger signal S1.

  Next, the destination information acquisition unit 204 acquires the label 110a of the optical signal 110 input to the signal input unit 201, and holds the destination information included in the label 110a (step S504). The destination information is held by a latch circuit and is latched at a predetermined timing. In parallel with the process in step S504, the process in step S505 is executed.

  In step S505, destination information candidate S2 is input. The destination information candidate S2 is output from the switch control unit 102 and output to the destination information match determination unit 205 via the destination information candidate input unit 206.

  The destination information match determination unit 205 determines whether the destination information matches the destination information candidate S2 (step S506). Here, the destination information match determination unit 205 compares the data sequence of the destination information acquired by the destination information acquisition unit 204 with the data sequence of the destination information candidate S2 input to the destination information candidate input unit 206 in bit units. Determine a match. When it is determined that they do not match (no match) (step S506: No loop), input of the next destination information candidate S2 in step S505 is awaited, and a match determination is performed for each input.

  On the other hand, when it is determined that there is a match (step S506: Yes), the destination information match determination unit 205 outputs a match flag S3 to the switch control unit 102 via the match flag output unit 207 (step S507). Thereafter, the destination information acquisition unit 204 resets the holding of the held destination information (step S508). As described above, the label recognition unit 101 ends the label recognition process for the input of the optical signal 110 of one packet.

  Note that the determination in step S506 only needs to be a determination regarding matching, and the matching flag S3 may be output upon matching. Therefore, during the mismatch period, no special processing is performed and the system waits with no response.

  FIG. 6 is a flowchart showing the operation contents of the switch control unit and the optical switch. First, switch control processing (step S600) executed by the switch control unit 102 will be described. The switch control unit 102 waits for input of the trigger signal S1 (step S601: No loop). When the trigger signal S1 output from the trigger output unit 203 of the label recognition unit 101 is input to the trigger input unit 301 (step S601: Yes), the following processing is executed.

  First, the table reading unit 302 reads the destination information candidates S2 one by one from the routing table 303 (step S602), and outputs the read destination information candidates S2 to the label recognition unit 101 via the destination information candidate output unit 304 ( Step S603). The read destination information candidate S2 is temporarily held in the destination information candidate holding unit 306.

  Next, the destination information candidate holding unit 306 waits for an input of the match flag S3 (step S604: No loop). When the match flag S3 is not input via the match flag input unit 305 during a predetermined cycle, the destination information candidate holding unit 306 returns to step S602, and the table read unit 302 sequentially reads new destination information candidates S2. And held (updated) in the destination information candidate holding unit 306.

  When the match flag S3 is input (step S604: Yes), the switch control signal S4 corresponding to the matched destination information candidate S2 is output to the optical switch 103 (step S605). The destination information candidate holding unit 306 outputs the destination information candidate S2 held when the match flag S3 is input to the switch control signal output unit 307. As a result, the switch control signal output unit 307 outputs the output port number (see FIG. 4) indicated by the destination information candidate S2 to the optical switch 103 as the switch control signal S4. Thus, the switch control unit 102 ends the switch control process for the input of the optical signal 110 of one packet.

  Next, the switch switching operation (step S610) in the optical switch 103 will be described. The optical switch 103 waits for an input of the switch control signal S4 from the switch control signal output unit 307 of the switch control unit 102 (see FIG. 3) (step S611: No loop). When the switch control signal S4 is input (step S611: Yes), the drive unit (not shown) provided in the optical switch 103 switches the switch so as to be an output port indicated by the switch control signal S4 (step S612). The switch control signal S4 is an output port indicated by the destination information candidate S2 (see FIG. 4) as described above, and the drive unit is an output port indicated by the destination information candidate S2 that matches the destination information of the optical signal 110. Switch the optical path by driving the switch. The optical switch 103 holds the switching state until the next switch control signal S4 is input. As described above, the optical switch control unit 103 ends the operation of switching the optical path for the input of the optical signal 110 of one packet.

  The processing contents shown in FIGS. 5 and 6 are executed each time the optical signal 110 of one packet is input. Then, when the optical signal 110 is input, the label recognition unit 101 detects the identification information and immediately outputs the trigger signal S1 to the switch control unit 102. When the packet of the optical signal 110 is input, the switch control unit 102 can immediately start reading the destination information candidate S2 from the routing table 303 and output the destination information candidate S2 to the label recognition unit 101. Thereby, the label recognition process in the label recognition unit 101 and the reading process of the destination information candidate S2 in the switch control unit 102 can be performed in parallel.

Therefore, the switch control unit 102 can output the destination information candidate S2 to the label recognition unit 101 until the label recognition unit 101 acquires the entire data string of the label 110a (destination information) of the optical signal 110. . The label recognizing unit 101 can execute the matching determination using the destination information candidate S2 immediately after the destination information latching is completed, so that the label recognition can be performed at high speed. That is, the label recognizing unit 101 performs clock frequency / phase synchronization processing every time an optical burst signal is input , acquires a data string of the entire destination information, and then determines the label at a higher speed than the configuration in which the path corresponding to the destination information is determined. Become able to recognize. Further, on the label recognition unit 101 side, it is possible to make a coincidence determination by a simple process of comparing the destination information candidates S2 sequentially output by the switch control unit 102 in bit units, and to speed up the process related to label recognition. Can do.

  In particular, when there are a large number of routes for routing, for example, when the number of output ports of the optical switch 103 is three or more, the present invention enables faster routing. In a configuration in which label recognition is performed using an optical switch provided with one input port and two output ports, it is necessary to increase the number of output ports by cascading a plurality of optical switches. The label recognition time is accumulated. On the other hand, according to the configuration of the present invention, as shown in FIG. 1, the selection of the output port in the optical switch 103 having 8 output ports can be performed by the series of processes shown in FIGS. In addition, since only one label recognition unit / switch control unit and one optical switch can be used, label recognition using an optical switch with a large number of output ports can be performed without increasing the size of the optical routing device. It can be done at high speed.

  Although the label recognition unit 101 and the switch control unit 102 described above are described as different blocks as shown in FIG. 1, they can be arranged in a single unit and operate independently. Although they have different functions, they can be incorporated into a single unit as a function for switching the optical switch 103.

  The optical routing device described above supports destination information in an asynchronous manner with the timing of acquiring destination information at the time before acquiring destination information when an intermittent optical signal with a label including destination information is input. It is possible to read out destination information candidates for determining the transfer destination. As a result, the time until label recognition is started is short, and label recognition can be performed at high speed. In addition, label recognition is a configuration in which each data string is compared in bit units when sequentially comparing a plurality of destination information candidates with destination information, and label recognition can be performed simply and without high load.

  As described above, the optical routing device and the optical routing method according to the present invention can perform label recognition at high speed, and are particularly suitable for nodes, switches, and optical cross-connects that route optical signals for each burst and switch paths. Yes.

It is a block diagram which shows the optical routing apparatus of this invention. It is a block diagram which shows the internal structure of a label recognition part. It is a block diagram which shows the internal structure of a switch control part. It is a chart which shows a routing table. It is a flowchart which shows the operation | movement content of a label recognition part. It is a flowchart which shows the operation content of a switch control part and an optical switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Optical routing apparatus 101 Label recognition part 102 Switch control part 103 Optical switch 110 Optical signal 110a Label 201 Signal input part 202 Label detection part 203 Trigger output part 204 Destination information acquisition part 205 Destination information matching judgment part 206 Destination information candidate input part 207 Match flag output unit 301 Trigger input unit 302 Table reading unit 303 Routing table 304 Destination information candidate output unit 305 Match flag input unit 306 Destination information candidate holding unit 307 Switch control signal output unit

Claims (8)

In an optical routing device that receives an optical burst signal to which a label including destination information is attached at a temporal head portion of an intermittent optical signal, and transfers the optical burst signal to a path corresponding to the destination information for each burst,
Label detection means for detecting identification information of input start of the label of the optical burst signal;
Destination information acquisition means for acquiring the destination information included in the label of the optical burst signal;
Branch means for branching and simultaneously inputting the optical burst signal to the label detection means and the destination information acquisition means;
Triggered by detection of the identification information by the label detection unit, a plurality of destination information candidates corresponding to the destination information of the optical burst signal are sequentially added to the destination information while the destination information acquisition unit holds the destination information for a certain period. Destination information match determination means for determining the match between the two,
Path setting means for setting the path of the input optical burst signal so as to correspond to the transfer destination indicated by the destination information when the determination result by the destination information match determination means matches;
An optical routing device comprising: And destination information candidate registering means before Symbol plurality of destination information candidates are registered in advance,
Trigger output means for outputting a trigger for requesting output of a plurality of destination information candidates when the identification information is detected by the label detection means;
Reading means for reading the plurality of destination information candidates registered in the destination information candidate registration means in a predetermined order based on the trigger output from the trigger output means and outputting the destination information match judgment means When,
The optical routing device according to claim 1, further comprising: A match determination process by the destination information match determination means;
3. The optical routing device according to claim 2, wherein the processing of reading the destination information candidate by the reading unit is performed in parallel and asynchronous with each other.   3. The optical routing device according to claim 2, wherein the destination information match determination unit determines, in bit units, a match between the destination information data string and the sequentially input destination information candidate data string.   The reading means reads a plurality of the destination information candidates registered in the destination information candidate registration means from the beginning, from the end, or randomly, according to a trigger output from the trigger output means. 2. The optical routing device according to 2.   The path setting means selects one of a plurality of output ports of an optical switch corresponding to the path indicated by the destination information candidate, and the optical burst signal input to the input port is selected as the selected output port. The optical routing apparatus according to claim 1, wherein the optical routing apparatus outputs the optical routing apparatus.   The optical routing device according to claim 6, wherein the optical burst signal is branched and input to the label detection unit and the optical switch. In an optical routing method in which an optical burst signal including destination information of the signal is input to a label of the burst signal, and the optical burst signal is transferred to a path corresponding to the destination information for each burst,
A label detection step of detecting identification information of input start of the label of the optical burst signal;
A destination information acquisition step of acquiring the destination information included in the label of the optical burst signal;
A branching step for branching the optical burst signal and causing the processing of the label detection step and the processing of the destination information acquisition step to be performed simultaneously;
Triggered by detection of the identification information by the label detection step, a plurality of destination information candidates corresponding to the destination information of the optical burst signal are sequentially added to the destination information while the destination information acquisition step holds the destination information for a certain period. A destination information match determination step for determining whether the two match,
A route setting step for setting the route of the input optical burst signal so as to correspond to the transfer destination indicated by the destination information candidate when the determination result by the destination information match determination step matches;
An optical routing method comprising:

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