JP5282048B2 - Switch, interface information creation method and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a time required to retrieve linking-up by a switch. <P>SOLUTION: Switches 10 constituting a network respectively create a WDM group obtained by putting together their own IFs in each multiplexing part 16 or demultiplexing part 17 connected to the IFs. The switches 10 respectively select one IF from the WDM group, and perform linking-up retrieval processing with respect to the IFs. When the linking-up retrieval of the IFs of the WDM group is successful here, linking-up retrieval processing of the other IFs of the same WDM group is performed. Switches 10 adjacent to each other perform such processing of IFs of the whole WDM groups. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

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. In addition, with the evolution of applications, video and audio up / downloads are becoming popular, and high-speed network lines are 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 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 for switches such as OXC and ROADM, random search is a technology for determining which IF (interface) is connected to an adjacent switch with an optical fiber link. (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 a link-up search signal is received from an adjacent switch 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 timing is different, the link-up of the IF cannot be confirmed. Therefore, in this method, as the number of IFs of the switch increases, there is a problem that the probability that link up can be confirmed between adjacent switches is reduced, and the search time for link up by the switch becomes longer. An object of the present invention is to solve the above-described problems and reduce the time required for a switch to search for a link-up.

  In order to solve the above-described problem, the switch of the present invention is connected to a WDM (Wavelength Division Multiplexing) network, and for each wavelength, an interface for transmitting a signal of the wavelength and multiplexing of wavelengths output from one or more interfaces. A multiplexing unit that outputs a multiplexed signal via a cable, a multiplexing unit that is input via a cable, a division unit that divides the multiplexed signal for each wavelength and outputs the multiplexed signal to the switch unit via the interface of the wavelength, and an input from the interface And a switch unit that outputs the signal of the wavelength to the interface that outputs the wavelength. This switch stores, for each demultiplexing unit and multiplexing unit, WDM group information indicating the demultiplexing unit or an interface connected to the multiplexing unit. Then, an interface is selected from its own interface group, and a test signal is output via the selected interface via the switch unit. When the test signal from the other switch is received via the interface, the identification information of the interface that has received the test signal, the identification information of the switch that is the transmission source of the test signal, and the transmission source of the test signal The identification information of the interface is associated and stored in the interface information of the storage unit. When a switch receives a test signal from the other switch via the interface, the switch refers to the WDM group information and the interface information. (1) Connects to the same demultiplexing unit or multiplexing unit as the interface If there is an interface that has not received a test signal from another switch, select an interface that has not received a test signal from another switch. When all the interfaces connected to the wave unit or multiplexing unit have received test signals from other switches, select the interface that has not received the test signals from other switches, and select the interface via the switch unit. The process of outputting the test signal via the interface is performed for all the events indicated in the WDM group information. Repeat until you run for the interface.

  In this way, adjacent switches select one IF from the interfaces (IFs) connected to the same demultiplexer and combiner (same WDM group), and adjacent switches Send test signal (link up search signal) to IF. When the switch receives a signal for link-up search from the adjacent switch side via the IF, the switch selects an IF that has not been searched for link-up in the WDM group to which the IF that received the signal belongs. A signal for link-up search is transmitted. Therefore, the time required for searching for the link-up of each IF can be reduced as compared with the case where the test signal is randomly transmitted from all the IFs of the switch.

  Further, the present invention is characterized in that the test signal output unit of the switch selects the control wavelength interface as the first interface to be selected from the interfaces connected to the demultiplexing unit and the multiplexing unit.

  In this way, the switch selects the control wavelength IF as an IF that transmits a signal for link-up search first from the WDM group. Therefore, when the switch creates the interface information related to the WDM group, first, the device ID of the adjacent switch can be stored. That is, IFs belonging to the WDM group include a control wavelength IF and a data wavelength IF, but generally, the data wavelength IF does not transmit information such as a device ID. On the other hand, the control wavelength IF transmits information including a device ID. Therefore, if the switch first receives a signal including the device ID of the adjacent switch by the control wavelength IF, then the signal transmitted by the data wavelength IF is a signal from the switch of the same device ID. I understand that there is. For example, if the switch first receives a signal including information “device ID“ 10B ”via the control wavelength IF, then the signal received via the data wavelength IF is the device ID“ 10B ”. It turns out that it is a signal from. Therefore, when the switch stores IF information included in the signal received via the data wavelength IF in the interface information, this information can be stored as IF information of the device ID “10B”.

  Moreover, this invention is a program for making the switch which is a computer perform the interface information preparation method of Claim 3.

  According to such a program, the interface information creation method according to claim 3 can be executed by a switch which is a computer.

  According to the present invention, the time required for the switch to search for a link-up 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 the structure of the switch of this Embodiment. It is the flowchart which showed the process sequence of the switch of FIG.

<Overview>
An embodiment of the present invention will be described. First, the processing outline of the switch 10 (10A, 10B) of the present 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 the following description, searching for a link-up means searching for an IF that is opposite to an IF that is linked to an adjacent switch 10. The switch 10 is an OXC or ROADM connected to a WDM (Wavelength Division Multiplexing) network. This switch switches the IF output from this signal in order to transfer the input signal to a predetermined device. Further, the switch 10 generates a wavelength multiplexed signal in which the wavelengths are bundled, and divides the input wavelength multiplexed signal for each wavelength, and the multiplexing unit 16 (16A, 16B) for transferring the wavelength multiplexed signal to the destination apparatus. And a demultiplexing unit 17 (17A, 17B). The multiplexing unit 16 and the demultiplexing unit 17 are connected by a link such as an optical fiber. In FIG. 1, descriptions of the multiplexing unit 16 in the switch 10A and the demultiplexing unit 17 in the switch 10B are omitted.

  In the present embodiment, IFs connected to the same multiplexing unit 16 or demultiplexing unit 17 are referred to as IFs belonging to the same WDM group. In addition, in one WDM group, there are two types of IFs: a data wavelength IF that carries an actual signal and a control wavelength IF that exchanges a control signal for transferring the actual signal between devices. Although FIG. 1 shows only one control wavelength IF for each multiplexing unit 16 or demultiplexing unit 17, the number is not actually limited to one. Note that the signal transmitted from the control wavelength IF includes the device ID of the transmission source of the signal and the ID of the transmission source IF. The link-up search signal transmitted from the data wavelength IF includes the ID of the transmission source IF. These signals may include the ID of the WDM group to which the transmission source IF belongs.

  First, the switches 10 </ b> A and 10 </ b> B search for a link-up from (1) IFs that have not yet been linked up (that is, IFs that have not been confirmed to be connected by the same link). That is, an IF (for example, a control wavelength IF) whose link-up has not been confirmed yet is selected, and a link-up search signal is transmitted to the selected IF. (2) After the successful link up of this IF, that is, when the switch 10A can receive a link-up search signal transmitted from the adjacent switch 10B by this IF, the same WDM group as this IF For other IFs, IF link-up search processing is performed.

  For example, when the link-up of the IF of “e” among the IFs of the switch 10A is successful, the link-up search process is performed for the IF of “f”, the IF of “g”, and the IF of “h” of the same WDM group. Do. If all the IFs in the same WDM group have succeeded in link-up, the process returns to (1). That is, a link-up search process is performed for IFs in other WDM groups. In this way, when the link-up search processing of each IF of the switch 10A is completed, for example, interface information 132 as shown in the balloon 101 is created. In the interface information 132 of FIG. 1, Local IF indicates the IF of its own switch 10, and Remote IF indicates the IF of the adjacent switch 10. R-node is the device ID of the adjacent switch 10, L-WDM G is the ID of the WDM group of its own switch 10, and R-WDM G indicates the ID of the WDM group of the adjacent switch 10. .

  In other words, the IF of the adjacent device (adjacent switch 10) connected via the link to the local IF “e” of the switch 10A is “a”, and the adjacent device connected via the link to the local IF “f” The IF of “b” indicates that the IF of the adjacent device connected to the local IF “g” via the link is “c”. The device ID of the adjacent device to which these IFs are connected is “10B”, the WDM group in the switch 10A of these IFs is “B”, and the WDM group in the adjacent device is “D”. Indicates that there is.

  As described above, when the switches 10A and 10B detect the link-up success, the switches 10A and 10B perform link-up search processing for other IFs in the WDM group to which the IF that detected the link-up success belongs. That is, since adjacent switches 10 perform link-up search processing for each WDM group, the link-up search processing of each IF is required as compared to the case where link-up search processing is randomly performed from all the IFs of the switch 10. Time can be reduced.

<Configuration>
Next, the configuration of the switch 10 will be described with reference to FIG. The switch 10 includes one or more of the switch unit 14, the multiplexing unit 16, and the branching unit 17 described above. 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 exchanging unit 124 includes an interface information creating unit 1241 and a test signal output unit 1242.

  When the interface information creation unit 1241 receives a test signal from another switch 10 (adjacent device) via the IF, the ID of the IF that has received the test signal and the device of the switch 10 that is the transmission source of the test signal The ID and the ID of the IF that is the transmission source of the test signal are associated with each other and stored in the interface information 132 (see FIG. 1) of the storage unit 13. The interface information creation unit 124 may receive the ID of the WDM group to which the IF that is the transmission source of the test signal belongs by the test signal, and store the ID of the WDM group in the interface information 132.

  The test signal output unit 1242 selects an IF that has not been successfully linked up with reference to the WDM group information 133 (described later) and the interface information 132. Then, a test signal is output from the selected IF via the switch control unit 123 and the switch unit 14. The IF selection here is performed as follows. That is, when the test signal output unit 1242 receives a test signal from an adjacent device via an IF, (1) the test signal output unit 1242 receives the test signal from the adjacent device in an IF of the same WDM group as the WDM group to which the IF belongs. If there is an IF that is not, select an IF from that IF. (2) When all the IFs in the same WDM group as the WDM group to which the IF belongs have already received the test signal from the other switch 10, the IF is selected from the IFs in the other WDM group. Here, the IF to be selected is, for example, a control wavelength IF of another WDM group. Then, the test signal output unit 1242 repeats the process of outputting the test signal from the selected IF via the switch unit 14 until all the interfaces indicated in the WDM group information 133 are executed.

  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 WDM group 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 ID 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. This is information in which an ID is associated with an ID of a WDM group to which the IF belongs (see FIG. 1). The interface information 132 is created by the interface information creation unit 1241.

  The WDM group information 133 indicates the IF connected to the demultiplexing unit 17 or the multiplexing unit 16 of the switch 10 as the IF of the same WDM group with respect to the IF connected to the same demultiplexing unit 17 or the multiplexing unit 16. Information. The WDM group information 133 illustrated in Table 1 indicates that the IF IDs “e”, “f”, “g”, and “h” are IFs that belong to the WDM group with the WDM group ID “B”. The WDM group information 133 may include information indicating whether each IF is a control wavelength IF or a data wavelength IF. The WDM group information 133 is referred to when the test signal output unit 1242 selects an IF for which a link-up search process is performed.

<Processing procedure>
Next, the processing procedure of the switch 10 will be described using FIG. 3 with reference to FIG. First, the test signal output unit 1242 of the switch 10 in FIG. 2 refers to the WDM group information 133 (see Table 1) and 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 adjacent device can be received via the selected IF, the interface information creation unit 1241 determines that 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 transmitted via the IF, and if the predetermined time has not yet passed (No in S8), the process returns to S2. On the other hand, if a predetermined time has passed since the start of transmitting 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 1242 refers to the WDM group information 133 (see Table 1) and the interface information 132, and if there is an IF that is not linked up with an IF in the same WDM group (Yes in S5), the same The IF is selected from the IFs that have not been successfully linked up with the IF of the WDM group (S6), and the process returns to S2.

  In S5, the test signal output unit 1242 refers to the WDM group information 133 (see Table 1) and the interface information 132, and if there is no IF that has not been successfully linked up with an IF in the same WDM group (No in S5). Then, it is determined whether or not link-up has been successfully performed for all IFs that are the target of the link-up search process (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.

  When such a switch 10 receives a test signal from the adjacent switch 10 side, it selects an IF that has not been successfully linked up in the WDM group to which the IF that has received the signal belongs, and transmits the test signal. . Therefore, the time required for searching for the link-up of each IF can be reduced as compared with the case where the test signal is randomly transmitted from all the IFs of the switch 10.

  In the embodiment described above, the switch 10 may select the control wavelength IF as the first IF to be selected. In this way, when the switch 10 creates the interface information 132 related to the WDM group, first, the device ID of the adjacent switch 10 can be stored. That is, the multiplexing unit 16 and the demultiplexing unit 17 have at least one control wavelength IF and data wavelength IF, but generally, information such as a device ID is not transmitted from the data wavelength IF. . On the other hand, the control wavelength IF transmits information including a device ID. Therefore, if the switch 10 first receives a signal including the device ID of the adjacent switch 10 by the control wavelength IF, then the signal transmitted by the data wavelength IF is transmitted from the switch 10 having the same device ID. It can be seen that For example, if the switch 10 first receives a signal including the information “device ID“ 10B ”via the control wavelength IF, then the signal received via the data wavelength IF is the device ID“ 10B ”. It can be seen that the signal is from Therefore, when the switch 10 stores the IF information included in the signal received via the data wavelength IF in the interface information 132, it can be stored as the IF information of the device ID “10B”.

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 WDM group information 1241 Interface information creation unit 1242 Test signal output unit

Claims (4)

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 multiplexed signals of wavelengths output from one or more of the interfaces via a cable;
A demultiplexing unit that divides a multiplexed signal input via a 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;
For each of the demultiplexing unit and the multiplexing unit, a storage unit that stores WDM group information indicating the demultiplexing unit or an interface connected to the multiplexing unit as a WDM group;
A test signal output unit that selects the interface and outputs a test signal via the selected interface via the switch unit;
When receiving the test signal from the other switch via the interface, the identification information of the interface that has received the test signal, the identification information of the switch that is the transmission source of the test signal, and the transmission source of the test signal An interface information creation unit that associates with the identification information of the interface and stores the interface information in the storage unit,
The test signal output unit includes:
When receiving the test signal from the other switch via the interface, refer to the WDM group information and interface information,
(1) When there is an interface that does not receive a test signal from the other switch among the interfaces of the same WDM group as the interface, the test signal from the other switch is selected from the interfaces of the WDM group. Select an interface that is not receiving
(2) When all the interfaces in the same WDM group as the corresponding interface have already received the test signal from the other switch, the test signal from the other switch is received from the interfaces of the WDM group other than the WDM group. Select an interface that is not
A switch characterized by repeating the process of outputting a test signal at the selected interface via the switch unit until it is executed for all the interfaces indicated in the WDM group information. The test signal output unit includes:
2. The switch according to claim 1, wherein a control wavelength interface is selected as the first interface to be selected from among the interfaces connected to the demultiplexing unit and the multiplexing unit. 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 multiplexed signals of wavelengths output from one or more of the interfaces via a cable;
A demultiplexing unit that divides a multiplexed signal input via a 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;
For each of the demultiplexing unit and the multiplexing unit, a switch including a storage unit that stores WDM group information indicating an interface connected to the demultiplexing unit or the multiplexing unit,
Selecting the interface and outputting a test signal via the selected interface via the switch unit;
When receiving the test signal from the other switch via the interface, the identification information of the interface that has received the test signal, the identification information of the switch that is the transmission source of the test signal, and the transmission source of the test signal In association with the identification information of the interface, and storing in the interface information of the storage unit,
When receiving the test signal from the other switch via the interface, refer to the WDM group information and interface information,
(1) When there is an interface that does not receive a test signal from the other switch among the interfaces of the same WDM group as the interface, the test signal from the other switch is selected from the interfaces of the WDM group. Selecting an interface that is not receiving
(2) When all the interfaces in the same WDM group as the corresponding interface have already received the test signal from the other switch, the test signal from the other switch is received from the interfaces of the WDM group other than the WDM group. Selecting an interface that has not been
A method of generating interface information, comprising: performing a process of outputting a test signal via the selected interface via the switch unit for all interfaces indicated in the WDM group information.   A program for causing the switch to execute the interface information creation method according to claim 3.

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