JP5331014B2 - Switch, interface information creation method and program thereof - Google Patents

Description

  The present invention relates to a technique in which each switch creates interface information in a WDM (Wavelength Division Multiplexing) network.

  In recent years, traffic has increased rapidly, and the increase is expected to accelerate in the future. Therefore, network technology for efficiently accommodating the increasing traffic is required. As applications evolve, video / audio upload / download has become popular, and network line speedup is desired. Transmission technology in optical networks is promising for realizing high-speed and large-capacity transmission. For example, WDM technology can multiplex and transmit the wavelength of light transmitting signals on a single optical fiber, and divide the wavelength with relay nodes such as OXC (Optical Cross Connect) and ROADM (Reconfigurable Optical Add Drop Multiplexer). By doing so, routing for each wavelength is realized. Therefore, it is possible to efficiently transmit a large volume of traffic with a small number of facilities. In addition, since the speed of light is faster than the speed of electricity, high-speed communication is possible.

  GMPLS (Generalized Multi-Protocol Label Switching) is widely used as a protocol for transmitting traffic in an optical network. Since GMPLS can advertise and collect necessary information in an autonomous and distributed manner, GMPLS has the advantage that it is easy to set up a path for transmitting traffic. However, there is a drawback that there are many parameters to be set in advance. Therefore, plug-and-play technology has been proposed for reducing human operations until a network is constructed and a service is started. Here, when implementing plug-and-play technology in switches such as OXC and ROADM, grasp which IF (interface) is connected to an adjacent switch with an optical fiber (search for link-up) There is a random search as a technique (see Non-Patent Document 1).

Kaori Shimizu, Rie Hayashi, Ichiro Inoue, Kohei Shiomoto, “Plug and Play Techniques for Optical Network Configuration,” IEICE Technical Report vol.109, no.102, NS2009-31 ~ NS2009-42, p45-48, 2009 June

  Here, in the random search, the target switches randomly select their own IF and transmit a link-up search signal (test signal) from the selected IF to the adjacent switch. When the test signal from the adjacent switch side is received via the selected IF, the switch determines that the IF is connected to the IF of the adjacent switch through a link. That is, if an adjacent switch selects an IF connected by the same link at the same timing and performs a link-up search process, the link-up related to this IF can be confirmed. However, if the test signal transmission timing is different, the link-up of the IF cannot be confirmed. Therefore, this method has a problem that, as the number of IFs of the switch increases, the probability that the link-up can be confirmed between adjacent switches decreases, and the time required for the link-up search by the switch increases. . Also, depending on the setting of the transmission time of the test signal per IF in each switch, the IF of the adjacent neighboring device may not be found forever and the search time may not converge. The present invention solves the above-described problem, avoids that the IF of the adjacent device (adjacent switch) that is the opposite in each switch is not found forever and avoids convergence of the search time, and reduces the time required for searching for the link-up of all IFs. The purpose is to reduce.

In order to solve the above-described problems, the present invention provides an interface for transmitting a signal of a wavelength connected to a WDM network and a multiplexed signal in which wavelengths output from one or more interfaces are bundled with a cable. A multiplexing part that is output via a cable, a multiplexed signal that is input via a cable, is divided for each wavelength, a demultiplexing part that is output to the switch part via the interface of the wavelength, and a signal of a wavelength that is input from the interface And a switch unit that outputs to the interface that outputs the wavelength. This switch stores unique device identification information assigned to its own switch. Then, the interface of the own switch that transmits the test signal is selected, and the transmission time of the test signal for searching for the link-up between the interface of the own switch and the interface of the adjacent switch is determined. The switch outputs the test signal from the selected interface to the adjacent switch via the switch unit during the determined test signal transmission time. When a switch receives a test signal from the adjacent switch at this interface, the switch identification information of the switch that received the test signal, the identification information of the adjacent switch, and the source of the test signal in the adjacent switch Interface information in which the identification information of the interface is associated is created. Further, when determining the test signal transmission time, this switch determines the test signal transmission time specific to its own switch based on the device identification information.

  By doing so, it is possible to provide a difference in the transmission time of the test signal of each switch, so that it is possible to avoid that the IF of an adjacent device facing each other in each switch is not found and the search time does not converge.

  The device identification information in the switch of the present invention is the device ID or IP address of the switch.

  In this way, the switch can determine the transmission time of the test signal based on the device ID of the switch (for example, the device ID assigned at the time of shipment of the switch) and the IP address of the switch.

  In addition, when determining the test signal transmission time, the switch of the present invention increases the number of interfaces that can be searched for link-ups with neighboring switches stored in the interface information, so that the test signal to the selected interface increases. Shorten the transmission time.

  By doing so, there is a high possibility that the time until each switch finishes the link-up search process for all interfaces can be shortened.

  Furthermore, when the switch of the present invention selects the interface of its own switch that transmits the test signal, the switch selects in the descending order of the wavelength assigned to each interface. In addition, when the switch of the present invention selects an interface of its own switch that transmits a test signal, the switch may be selected in ascending order of wavelengths assigned to each interface.

  In this way, the order of IFs for which the link-up search process is performed in each switch becomes the same, so that the link-up search process for all IFs can be completed in a shorter time.

  Further, the present invention is a program for causing a switch to execute the interface information creation method of the present invention.

  According to such a program, the interface information creation method of the present invention can be executed on a general switch.

  According to the present invention, it is possible to avoid that the IF of an adjacent device (adjacent switch) that is opposite in each switch is not found forever and the search time for link up does not converge. As a result, the time required for searching for the link-up of all IFs can be reduced.

It is the figure which showed notionally the operation | movement outline | summary of the switch of this Embodiment. It is the figure which showed notionally the operation | movement outline | summary of the switch of this Embodiment. It is the figure which showed the structure of the switch of this Embodiment. It is the flowchart which showed the process sequence of the switch of FIG. It is the flowchart which showed the process sequence of the switch of FIG.

  Embodiments of the present invention will be described below. First, the processing outline of the switch 10 of this embodiment will be described with reference to FIG. Here, a case where a link-up search signal is transmitted between the switches 10A and 10B to search for a link-up will be described as an example. The switch 10 includes an IF for each wavelength of the signal. Then, in order to transfer the input signal to a predetermined device, the IF that outputs this signal is switched. In addition, the switch 10 generates a wavelength multiplexed signal in which the wavelengths are bundled and transfers the multiplexed signal to the destination device 16 (16A, 16B) and the input wavelength multiplexed signal for each wavelength. And a wave portion 17 (17A, 17B) (see FIG. 1). The multiplexing unit 16 and the demultiplexing unit 17 are connected by a link such as an optical fiber. When the switch 10 detects link connection, the switch 10 searches for a link up of each IF. Searching for link-up means searching for an IF of an adjacent device (switch 10) linked to the IF of its own switch 10. Specifically, a link-up search signal is transmitted from its own switch 10, and a link-up search signal is also received from an adjacent device (switch 10), thereby adjacent to the IF facing itself. This is to identify which switch 10 is a device and which IF of the switch 10 is an opposite IF. Based on the identification result, interface information 132 as shown in the balloon 101 of FIG. 1 is created. The switch 10 is an OXC, ROADM, or the like connected to the WDM network, and device identification information that is unique identification information is assigned to each switch 10.

  The switch 10 (10A, 10B) selects an IF for which a link-up search process is to be performed from among the IFs included in the switch 10 thereof. Then, the switch 10 continues to transmit a link-up search signal (test signal) for a predetermined time using the selected IF. Here, the time for which the switch 10 continues to transmit the test signal (test signal transmission time) is specific to each switch 10 based on the device identification information of the switch 10 (for example, the device ID assigned to the switch 10 at the time of shipment). Time.

  This will be conceptually described with reference to FIG. For example, the switch 10A determines the transmission time t1 of the test signal of the switch 10A based on its own device ID “10”. Then, a test signal is transmitted from the IF of wavelength “λ2” to t1, and a link-up search process is performed. When the test signal from the switch 10B side cannot be received, the test signal is transmitted from the IF of wavelength “λ4” for t1, and the link-up search process is performed. Further, a test signal is transmitted from the IF of wavelength “λ3” for t1, and a link-up search process is performed.

  On the other hand, for example, the switch 10B determines the transmission time t2 of the test signal of the switch 10B based on its own device ID “20”. Then, a test signal is transmitted from IF of wavelength “λ3” to t2, and a link-up search process is performed. When the switch 10A receives the test signal from the switch 10B during the link-up search process of the IF of the wavelength “λ3”, the switches 10A and 10B have successfully linked up to the IF of the wavelength “λ3”. . Next, the switches 10A and 10B perform a link-up search process for IFs other than the IF of the wavelength “λ3”. For example, the switch 10A transmits a test signal from the IF of the wavelength “λ4” to t1, and performs a link-up search process. When the test signal from the switch 10B side cannot be received, the test signal is transmitted from the IF of wavelength “λ2” for t1, and the link-up search process is performed. When the switch 10A receives the test signal from the switch 10B during the link-up search process for the IF of the wavelength “λ2”, the switches 10A and 10B have succeeded in the link-up for the IF of the wavelength “λ2”. . Next, the switches 10 </ b> A and 10 </ b> B perform a link-up search process for IFs other than the IFs with wavelengths “λ3” and “λ2”. The switches 10A and 10B search the IF of the adjacent device that is opposite to each IF by repeating the above processing, and record the result in the interface information 132 (see FIG. 1).

  In this way, by setting a large or small difference in the time required for the link-up search process per IF in each switch 10 that performs the link-up search process, it is possible to avoid that the IF of the adjacent adjacent device cannot be found indefinitely. be able to.

<Configuration>
Next, the configuration of the switch 10 will be described with reference to FIG. The switch 10 includes at least one switch unit 14, a multiplexing unit 16, and a demultiplexing unit 17. And this switch 10 is provided with the control part 12 which controls the switch part 14, and the memory | storage part 13 which memorize | stores the various information referred when the control part 12 controls.

  The control unit 12 is realized by a dedicated circuit included in the switch 10 or a program execution process by a CPU (Central Processing Unit). Further, the storage unit 13 includes a storage medium such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a flash memory. When the switch 10 is realized by a program execution process, the storage unit 13 stores a program for realizing the function of the switch 10.

  The control unit 12 includes a signaling unit 121, an information advertisement collection unit 122, a switch control unit 123, and an adjacent information exchange unit 124.

  The signaling unit 121 exchanges signaling with neighboring devices when setting a path for signal transmission in an autonomous and distributed manner within the network. An example of a signaling protocol is RSVP (Resource reSerVation Protocol).

  The information advertisement collecting unit 122 advertises and collects information necessary for setting a path between devices in the network. Examples of protocols used here include OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol).

  The result of signaling by the signaling unit 121 and information (route information and the like) collected by the information advertisement collecting unit 122 are stored in the database 131. These pieces of information are referred to when the control unit 12 transmits / receives data.

  The adjacent information exchanging unit 124 exchanges information such as which IF of the adjacent device each IF of its own switch 10 is connected to the adjacent device. An example of a protocol for exchanging this information is LMP (Link Management Protocol). The adjacent information exchange unit 124 includes an interface selection unit 1241, a transmission time determination unit 1242, an interface information creation unit 1244, and a test signal output unit 1243.

  The interface selection unit 1241 refers to the interface information 1244 and selects an IF that has not been successfully linked up from the IFs of its own switch 10.

  The transmission time determination unit 1242 determines the transmission time of the test signal for searching for link-up with the IF of the adjacent device. For example, the transmission time determination unit 1242 determines the transmission time of its own switch 10 according to a predetermined calculation formula based on the device identification information 133 stored in the storage unit 13. Note that this calculation formula is such that if the value (device identification information 133) used as a parameter is unique, the calculation result also has a unique value.

  The test signal output unit 1243 refers to the interface information 132 and selects an IF that has not been successfully linked up. Then, a test signal is output from the selected IF via the switch control unit 123 and the switch unit 14.

  The interface information creation unit 1244 receives the test signal from the adjacent device via the IF, that is, when the link up is successful, the ID of the IF that received the test signal, and the switch of the transmission source of the test signal The device identification information 133 of 10 and the ID of the IF of the transmission source of the test signal are associated with each other and stored in the interface information 132 of the storage unit 13.

  The switch control unit 123 issues a command for appropriately switching the target signal to the switch unit 14.

  Next, the storage unit 13 will be described. The storage unit 13 stores a database 131, interface information 132, and device identification information 133.

  As described above, the database 131 stores the results of signaling by the signaling unit 121 and information (route information and the like) collected by the information advertisement collection unit 122. Information in the database 131 is referred to when the control unit 12 transmits / receives a signal using a path established with another apparatus.

  The interface information 132 includes the ID of the IF of the switch 10 that has received the test signal from the adjacent device, the device identification information of the adjacent device that is the transmission source of the test signal, and the IF of the transmission source of the test signal in the adjacent device. And an ID of a WDM group to which the IF belongs (an IF group bundled by the same multiplexing unit 16 or demultiplexing unit 17) (see balloon 101 in FIG. 1). The interface information 132 is created by the interface information creation unit 1244. As shown in a balloon 101 in FIG. 1, the interface information 1244 may further include information on the wavelength assigned to each IF.

  The device identification information 133 is identification information unique to the switch 10. The device identification information 133 is, for example, an IP address assigned to the switch 10 or a device ID assigned when the switch 10 is shipped. When the transmission time determination unit 1242 determines the transmission time of the test signal based on the device identification information 133, when the device identification information 133 includes characters and symbols, the device identification information 133 is converted into a numerical value. Convert. And the transmission time of a test signal is determined using this numerical value.

<Processing procedure>
Next, the processing procedure of the switch 10 will be described with reference to FIG. The following processing is assumed to be triggered by the connection of a link (such as an optical fiber cable) to the switch 10. First, the transmission time determination unit 1242 of the switch 10 in FIG. 3 refers to the device identification information 133 of its own switch 10, and searches for a test signal per IF for searching for a link-up with an IF of an adjacent device. Is determined (S0). Next, the test signal output unit 1243 refers to the interface information 132 and selects an IF that has not been successfully linked up (S1). Then, a test signal is transmitted from the selected IF to the adjacent device via the switch control unit 123 and the switch unit 14 (S2). Here, if the link-up is successful (Yes in S3), that is, when the test signal from the neighboring device can be received via the selected IF, the interface information creation unit 1244, the IF that succeeded in the link-up Is stored in the interface information 132 (S4). On the other hand, if the link up is not successful (No in S3), the test signal is started to be transmitted via the IF, and if the transmission time determined in S0 has not yet passed (No in S8), the process returns to S2. . On the other hand, if the transmission time determined in S0 has elapsed after starting to transmit a test signal via the IF (Yes in S8), the process returns to S1 to select another IF that is not linked up.

  In S5, the test signal output unit 1243 refers to the interface information 132, and if there is an IF that has not been successfully linked up yet (Yes in S5), the interface information 132 is an IF from the IF that has not been successfully linked up yet. Is selected (S6), and the process returns to S2.

  In S5, the test signal output unit 1243 refers to the interface information 132, and if there is no IF that has not been successfully linked up (No in S5), the test signal output unit 1243 links up all the IFs that are the targets of the link up search process. It is determined whether or not (S7). If there is an IF that has not been successfully linked up (No in S7), the process returns to S1. On the other hand, if the link-up is successful for all IFs that are the target of the link-up search process (Yes in S7), the process ends.

  In this way, the switches 10 that perform the link-up search process have different test signal transmission times per IF. Therefore, the switch 10 can avoid that the IF of the adjacent adjacent device is not found forever.

  When the transmission time determination unit 1242 determines the transmission time of the test signal, the more the number of IFs that have been successfully linked up (link up was found) stored in the interface information 1244, the more the test is performed. You may make it shorten the transmission time of a signal. This is because the test signal output unit 1243 is more likely to succeed in link-up if the number of IFs that have not succeeded in link-up decreases, even if the test signal is not continuously transmitted for a long time.

  In addition, when selecting an IF that transmits a test signal, the interface selection unit 1241 of each switch 10 may select a descending order if the wavelength assigned to each IF is in descending order and an ascending order if the order is ascending. For example, both the switches 10A and 10B select IFs in descending order of wavelength and perform link-up search processing. By doing in this way, since the order of IF which performs a link-up search process between the adjacent switches 10 becomes the same, the link-up search process for all IFs can be completed in a shorter time.

  Further, when the switch 10 determines the transmission time of the test signal, it may be as follows. For example, each switch 10 in the system stores the test signal transmission time (transmission time t1, t2) in the storage unit 13 in advance. Here, the transmission times t1 and t2 are different values, for example, transmission time t2> transmission time t1.

  The switch 10 determines the test signal transmission time according to the procedure shown in FIG. First, the interface selection unit 1241 of the switch 10 refers to the interface information 132 and selects a control wavelength IF from among IFs. Then, the test signal output unit 1243 performs a link-up search process for the control wavelength IF (S11). Note that the transmission time of the test signal in the link-up search processing of the control wavelength IF is transmission time t1, t2 or any other transmission time. When the link up of the control wavelength IF is successful (Yes in S12), the device identification information of the adjacent device is received along with the test signal from the adjacent device via the control wavelength IF. For example, the device ID of the adjacent device is received. Then, the transmission time determination unit 1242 compares the device ID of this adjacent device with the device ID of its own switch 10 (S13). The comparison of the device IDs here is performed, for example, by converting the numerical values of the respective device IDs and comparing the numerical values corresponding to the respective device IDs.

  Here, for example, when the device ID of its own switch 10 is smaller than the device ID of the adjacent device (Yes in S14), the transmission time determination unit 1242 transmits the test signal transmission times t1 and t2 stored in the storage unit 13. Among them, the transmission time t1 is selected (S15). On the other hand, when the device ID of its own switch 10 is larger than the device ID of the adjacent device (No in S14), the transmission time determination unit 1242 selects the transmission time t2 (S16). Then, the switch 10 performs a link-up search process for the data wavelength IF using the transmission time (transmission time t1 or transmission time t2) selected in S15 or S16. The switch 10 executes such processing for each WDM group and performs link-up search processing for all IFs. In this way, each switch 10 can perform IF link-up search processing.

  In the example described above, the transmission time determination unit 1242 of each switch 10 selects the transmission time t1 from the transmission times t1 and t2 when the device ID of its own switch 10 is smaller than the device ID of the adjacent device. However, the transmission time t2 may be selected. That is, the transmission time determination unit 1242 of each switch 10 has a common rule as to which transmission time is selected when the device ID of its own switch 10 is smaller (or larger) than the device ID of the adjacent device. Each switch 10 selects a transmission time according to the rule. Even in this way, adjacent switches 10 transmit test signals at different transmission times, so that the search time in the link-up search process does not converge.

10 (10A, 10B) switch 12 control unit 13 storage unit 14 switch unit 16 multiplexing unit 17 demultiplexing unit 121 signaling unit 122 information advertisement collecting unit 123 switch control unit 124 adjacent information exchanging unit 131 database 132 interface information 133 device identification information 1241 Interface selection unit 1242 Transmission time determination unit 1243 Test signal output unit 1244 Interface information creation unit

Claims (7)

An interface that is connected to a WDM (Wavelength Division Multiplexing) network and transmits a signal of the wavelength for each wavelength;
A multiplexing unit that outputs a multiplexed signal in which wavelengths output from one or more of the interfaces are bundled via a cable;
A demultiplexing unit that divides a multiplexed signal input via the cable for each wavelength and outputs the multiplexed signal to the switch unit via the interface of the wavelength;
A switch that outputs a signal of a wavelength input from the interface to an interface that outputs the wavelength;
A storage unit for storing unique device identification information assigned to its own switch;
An interface selector for selecting the interface of its own switch for transmitting a test signal,
And interface of the own switch, a transmission time determination unit for determining a transmission time of the test signal for searching for a link-up with the adjacent switch interface,
During the transmission time of the determined test signal from the selected interface, and the via switch section outputs the test signal to the adjacent switch test signal output unit,
When the test signal from the adjacent switch is received by the interface, the identification information of the interface of the own switch that has received the test signal, the identification information of the adjacent switch, and the test signal in the adjacent switch An interface information creation unit that creates interface information in association with identification information of a transmission source interface;
The transmission time determination unit
A switch characterized in that, based on the device identification information, a transmission time of the test signal specific to the switch itself is determined. The device identification information is
2. The switch according to claim 1, which is a device ID or an IP address of the switch. The transmission time determination unit
When determining the transmission time of the test signal, the stored in the interface information, the higher the link-up with an adjacent switch becomes large number of interfaces which can be searched, the transmission time of the test signal to the selected interface The switch according to claim 1 or 2, wherein the switch is shortened. The interface selection unit
The switch according to any one of claims 1 to 3, wherein when selecting an interface for transmitting the test signal, the interfaces are selected in descending order of wavelengths assigned to the interfaces. The interface selection unit
The switch according to any one of claims 1 to 3, wherein when selecting an interface for transmitting the test signal, the interfaces are selected in ascending order of wavelengths assigned to the interfaces. An interface that is connected to a WDM (Wavelength Division Multiplexing) network and transmits a signal of the wavelength for each wavelength;
A multiplexing unit that outputs a multiplexed signal in which wavelengths output from one or more of the interfaces are bundled via a cable;
A demultiplexing unit that divides a multiplexed signal input via the cable for each wavelength and outputs the multiplexed signal to the switch unit via the interface of the wavelength;
A switch unit that outputs a signal of a wavelength input from the interface to an interface that outputs the wavelength;
A switch comprising a storage unit for storing unique device identification information assigned to the switch of its own,
Determining a transmission time of a test signal for searching for a link-up with an interface of an adjacent switch from the interface of the own switch;
Selecting an interface of its switch to transmit the test signal;
During the test signal transmission time and the determined, from said selected interface, via the switching unit, and outputting the test signal to the adjacent switch,
When the test signal from the adjacent switch is received by the interface, the identification information of the interface of the own switch that has received the test signal, the identification information of the adjacent switch, and the test signal in the adjacent switch Executing the step of creating interface information in association with the identification information of the source interface,
Determining the transmission time of the test signal;
Interface information creation method characterized by determining a transmission time of specific the test signal based on the device identification information, the own switch.   A program for causing the switch to execute the interface information creation method according to claim 6.

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