JP4854624B2 - Transmission / reception wavelength information acquisition method and optical transmission / reception apparatus - Google Patents

Description

  The present invention is used in an optical communication system that performs transmission and reception using a plurality of wavelengths. In particular, the present invention relates to a technique for acquiring information on a wavelength that can be communicated with a desired optical transmission / reception device in a communication system in which wavelengths that can be communicated are different for each optical transmission / reception device.

  Communication with different transmission / reception devices or applications is realized by transmitting / receiving data by identifying a partner by an identifier defined in each logical layer. This identifier is called an IP (Internet Protocol) address in the network layer and a MAC (Media Access Control) address in the data link layer, and is used to identify the transmission / reception device.

  When communicating with a transmission / reception apparatus having a certain IP address, it is necessary to acquire the MAC address of the transmission / reception apparatus when directly connected to the transmission / reception apparatus having a desired IP address. Further, when connected to the transmitting / receiving device via a different transmitting / receiving device, it is necessary to acquire the MAC address of the transmitting / receiving device directly connected to the own transmitting / receiving device among the transmitting / receiving devices passing through.

  A typical method for acquiring a MAC address from an IP address is ARP (Address Resolution Protocol) defined by RFC826 in Non-Patent Document 1.

  The flow of MAC address acquisition using ARP will be described below with reference to FIGS. A transmission / reception apparatus that attempts to transmit a data frame first searches for an IP address that matches the transmission destination IP address of the data frame in a correspondence table that describes the correspondence between the IP address and the MAC address of each transmission / reception apparatus. (701-704). If there is a matching IP address in the correspondence table, the MAC address is extracted from the correspondence table, set as the transmission destination MAC address of the data frame, and transmitted (707). If there is no matching IP address in the correspondence table, the destination MAC address is obtained by performing the ARP request processing (705).

  FIG. 8 shows the flow of the ARP request process. First, a request frame storing a transmission source IP address, a transmission source MAC address, and a transmission destination IP address is created and transmitted (801 to 805). Since the transmission destination MAC address is unknown at this time, the broadcast address is stored in the transmission destination MAC address area of the header of the Ethernet (registered trademark) frame.

  FIG. 9 shows the flow of processing of each transmitting / receiving device that has received the request frame. The transmitting / receiving apparatus that has received the request frame first compares the destination IP address in the request frame with the IP address of the own transmitting / receiving apparatus (901). If the IP addresses are the same, the IP address and MAC address of the transmission / reception apparatus that transmitted the request frame are added to the correspondence table (902).

  Next, a response frame storing its own IP address and MAC address is created and transmitted to the transmission / reception apparatus that has transmitted the request frame (903 to 907). When the transmission / reception apparatus that has transmitted the request frame receives the response frame (806), the IP address and the MAC address in the response frame are added to the correspondence table (807), and the acquisition of the transmission destination MAC address is completed. However, if the response frame cannot be received even after a predetermined time, it is assumed that there is no transmission / reception apparatus having the corresponding IP address on the network, and an error is returned as the transmission destination is unknown (708).

  Also, in each transmitting / receiving device, the correspondence between the IP address obtained by ARP and the MAC address is stored in the memory in the transmitting / receiving device for several minutes to several hours, so that frequent ARP inquiries occur. prevent.

As another method, for example, as shown in Patent Document 1, there is a method of installing a management device that centrally manages the correspondence between the IP addresses and MAC addresses of all transmission / reception devices on the network.
JP 2003-348084 A IETF RFC826 (“Packet Generation” and “Packet Reception”)

  In the case of a communication system in which a wavelength that can communicate with each optical transmission / reception device is different in a network using a plurality of wavelengths, information on the wavelengths that can be communicated with each optical transmission / reception device is the IP address and data in the network layer. Like a MAC address in the link layer, it functions as a kind of identifier in the physical layer.

  In other words, when performing communication between optical transceivers, it is necessary to obtain information on wavelengths that enable communication with the counterpart optical transceiver, just as the MAC address is obtained from the IP address by ARP.

  However, there is no established method for acquiring information on such wavelengths as needed by each optical transmission / reception device, such as acquisition of a MAC address by ARP. In this method, the wavelength information of other optical transmission / reception devices related to the own device is held in advance.

  However, in the method of centrally managing the wavelength information with the management device, all communication is impossible when the management device malfunctions, and where the management device is installed and how it is maintained Is a problem.

  Further, in the method in which each optical transmission / reception apparatus holds information on the wavelengths of other optical transmission / reception apparatuses related to the own apparatus in advance, a plurality of optical transmission / reception apparatuses including the optical transmission / reception apparatus of the communication partner before actual communication is performed. It is necessary to redundantly store the wavelength information of each wavelength, and every time the network configuration changes, it is necessary to exchange information of a new wavelength between the optical transmission and reception devices, which increases traffic for the communication. There are problems such as hindering the effective use of the network and the time required to update the wavelength information in each optical transceiver.

  Therefore, it is desirable that a method can be established in which each optical transmission / reception apparatus can acquire wavelength information at any time, as in the case of MAC address acquisition.

  The present invention has been made to solve such a problem, and is a network using a plurality of wavelengths, and in a communication system in which wavelengths that can be communicated are different for each optical transmission / reception apparatus, It is an object of the present invention to provide a transmission / reception wavelength information acquisition method and an optical transmission / reception apparatus capable of acquiring a wavelength communicable with an optical transmission / reception apparatus as needed.

  The present invention includes a plurality of optical transmission / reception devices and an optical transmission path connecting the plurality of optical transmission / reception devices, and the optical transmission / reception devices perform transmission / reception at a plurality of wavelengths, and different wavelengths can be communicated for each optical transmission / reception device. It is a transmission / reception wavelength information acquisition method used in a communication system.

  Here, the feature of the present invention is that, when acquiring the MAC address from the IP address of the optical transmission / reception device of the communication partner by ARP, requests are made in a predetermined order for each wavelength that the own optical transmission / reception device can transmit. The frame is transmitted, and the wavelength at which the response frame is returned first is stored as the transmission / reception wavelength used for communication with the communication partner optical transmission / reception apparatus.

  Alternatively, when acquiring the MAC address from the IP address of the communication partner optical transmitter / receiver by ARP, the request frame is transmitted at a plurality of wavelengths that can be transmitted by the own optical transmitter / receiver, and the response frame is returned in advance. The highest wavelength in the determined priority order is stored as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner.

  The present invention can also be viewed from the viewpoint of an optical transceiver. That is, the present invention includes a plurality of optical transmission / reception devices and an optical transmission path connecting the plurality of optical transmission / reception devices, and the optical transmission / reception devices perform transmission / reception at a plurality of wavelengths, and the wavelengths that can be communicated for each optical transmission / reception device. Is an optical transceiver used in different communication systems.

  Here, the feature of the present invention is that information storage means for storing the IP address, MAC address, and transmission / reception wavelength for other optical transmission / reception devices, and the communication partner in the information stored by the information storage means. An information search means for searching whether there is information on the optical transceiver, and an inquiry to the optical transceiver of the communication partner when there is no information on the optical transceiver of the communication partner in the information storage means And transmitting / receiving wavelength information acquisition means for acquiring information.

  For example, when the MAC address is acquired from the IP address of the optical transmission / reception device of the communication partner by ARP, the transmission / reception wavelength information acquisition unit is configured to request frames in a predetermined order for each wavelength that can be transmitted by the own optical transmission / reception device. And a means for storing a wavelength at which a response frame is first returned as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner.

  Alternatively, the transmission / reception wavelength information acquisition means transmits a request frame at a plurality of wavelengths that can be transmitted by the own optical transmission / reception device when acquiring the MAC address from the IP address of the optical transmission / reception device of the communication partner by ARP, It is also possible to provide means for storing the highest wavelength in the priority order determined in advance as the transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner.

  Note that the information storage unit of the present invention does not need to hold redundant information on the wavelengths of a plurality of optical transmission / reception devices including the optical transmission / reception device of the communication partner before the actual communication is performed as in the prior art. . According to the present invention, since wavelength information can be acquired by ARP prior to actual communication, there may be no information at the initial stage, for example. That is, the information storage means of the present invention is means for learning wavelength information from the history of communications performed previously and holding the learning results.

  The present invention can also be viewed from the viewpoint of an optical communication system. That is, the present invention is an optical communication system including the optical transmission / reception apparatus of the present invention and an optical transmission path connecting the plurality of optical transmission / reception apparatuses.

  In an optical communication system in which wavelengths that can be communicated are different for each optical transmission / reception device in a network using a plurality of wavelengths by using the present invention, the MAC address is acquired from the IP address of the optical transmission / reception device of the communication partner by ARP. At the same time, information on the transmission / reception wavelength that can communicate with the optical transmission / reception apparatus of the communication partner can be acquired.

  Further, by using the method of the present invention, it is possible to acquire information on the MAC address and transmission / reception wavelength of the optical transmission / reception apparatus of the communication partner with the minimum communication traffic. Alternatively, even when the number of wavelengths is large, it is possible to acquire the MAC address and transmission / reception wavelength information of the optical transmission / reception apparatus of the communication partner within a certain time.

(First Example)
A first embodiment of the present invention will be described with reference to FIGS. This embodiment is a basic configuration of the present invention, in which a plurality of optical transmission / reception devices are connected by an optical transmission line, and communication between each optical transmission / reception device can be performed by optical signals having one or a plurality of wavelengths. This is an example in which a request frame is sequentially transmitted at each wavelength in order to obtain information on the MAC address of the communication partner and the communicable wavelength in the network.

  As shown in FIG. 1, an Ethernet frame is composed of a preamble 101, a destination MAC address 102, a source MAC address 103, a frame type 104, data 105, and an FCS (Frame Check Sequence) 106. In order to facilitate identification within the optical transmission / reception apparatus, as shown in FIG. 1, a region 111 representing a transmission / reception wavelength in a part of the preamble region 101 in the header of the Ethernet frame and an error detection region in the region 111 112 is provided. Each optical transmission / reception device has a correspondence table that stores correspondence relationships between IP addresses, MAC addresses, and transmission / reception wavelengths of other optical transmission / reception devices on a memory.

  FIG. 2 shows the configuration of the optical transceiver used in the present invention. The data frame input to the local receiver 201 is stored in the transmission buffer memory 203 and delivered to the header reading unit 202. The header reading unit 202 reads the destination IP address in the data frame and passes it to the ARP control unit 230. The ARP control unit 230 refers to the correspondence table 231 and checks whether there is an item in the correspondence table 231 that has an IP address that matches the destination IP address.

  If there is an item that matches the destination IP address, the output control unit 204 rewrites the destination MAC address of the data frame to the MAC address stored in the correspondence table 231.

  In addition, the region 111 indicating the transmission / reception wavelength is rewritten with the transmission / reception wavelength information obtained from the correspondence table 231, and the error detection code is recalculated using the value of the region 111 to update the region 112. Further, the switch 205 is controlled to output a data frame to a port corresponding to the transmission wavelength, converted into an optical signal by a transmitter corresponding to the designated wavelength among the transmitters 211 to 21N, and then the optical transmission path 290. Send to.

  If there is no item in the correspondence table 231 that matches the destination IP address, the output control unit 204 generates an ARP request frame and transmits it to try to obtain the MAC address and transmission / reception wavelength. The processing procedure at this time is shown in FIG.

  First, an ARP request frame is created (301 to 304), and a value indicating the wavelength at which the request frame is transmitted is stored in an area 111 representing the transmission / reception wavelength of the preamble area 101 and transmitted.

  In each optical transmission / reception apparatus that has received the request frame, the request frame is first converted into an electrical signal by the wavelength demultiplexer 256 and the receivers 261 to 26N and stored in the reception buffer memory 257. Thereafter, the frame identification unit 258 divides the frame into a normal data frame and an ARP frame, and the request frame is sent to the ARP control unit 230. Then, the ARP control unit 230 processes the request frame according to the procedure of FIG.

  If the optical transmitter / receiver specified by the destination IP address receives the request frame, the information in the request frame is stored in the correspondence table (402), and then a response frame is created (403-406) and transmitted. To do. When receiving the response frame (307), the optical transmission / reception apparatus that has transmitted the request frame stores the transmission source IP address, transmission source MAC address, and transmission / reception wavelength information in the preamble area in the response table 231 ( 308), the data frame is transmitted.

  However, if communication with the optical transmission / reception apparatus specified as the transmission destination IP address is impossible at the wavelength at which the request frame is transmitted, the optical transmission / reception apparatus having an IP address that matches the transmission destination IP address of the request frame No response frame is returned because the request frame does not arrive. Therefore, if no response frame is returned after a certain period of time (309), it is determined that communication is not possible at that wavelength, and a request frame is transmitted using a different wavelength (310, 311).

  At this time, the order of wavelengths used for transmission is determined by a predetermined order or a random number. When response frames are not returned for all wavelengths that can be transmitted (310), the optical transceiver having the IP address is It is determined that it does not exist on the network, and the data frame is discarded (APR request processing ends).

  By using the method of this embodiment, it is possible to acquire information on the transmission destination MAC address and transmission / reception wavelength with the minimum communication traffic.

(Second embodiment)
A second embodiment will be described with reference to FIGS. The difference between this embodiment and the first embodiment is that, in the first embodiment, a request frame is transmitted at the next wavelength when a response frame does not arrive even after a predetermined time has elapsed since the request frame was transmitted at a certain wavelength. However, in this embodiment, the request frame is transmitted at a plurality of wavelengths that can be transmitted without waiting for the response frame to arrive. In the present embodiment, the request frame is described as being transmitted at all transmittable wavelengths, but this is not necessarily the case.

  Further, the configuration of the optical transmission / reception apparatus in the present embodiment is the configuration shown in FIG. 2 as in the first embodiment. The data frame input to the local receiver 201 is stored in the transmission buffer memory 203 and delivered to the header reading unit 202. The header reading unit 202 reads the destination IP address in the data frame and passes it to the ARP control unit 230. The ARP control unit 230 refers to the correspondence table 231 and checks whether there is an item in the correspondence table 231 that has an IP address that matches the destination IP address.

  If there is an item that matches the destination IP address, the data frame is converted into an optical signal of a predetermined wavelength by the same procedure as in the first embodiment, and transmitted to the optical transmission line 290.

  However, if there is no item in the correspondence table 231 that matches the transmission destination IP address, the output control unit 204 generates an ARP request frame and transmits it to try to acquire information on the MAC address and transmission / reception wavelength. The processing procedure at this time is shown in FIG. First, an ARP request frame is created (501 to 504), and then the request frame is transmitted at all wavelengths that can be transmitted by the optical transceiver (505 to 509).

  Each optical transmission / reception apparatus that receives the request frame processes the request frame in the same procedure as in the first embodiment. If the optical transmission / reception apparatus designated as the destination IP address in the request frame has received the request frame, the optical transmission / reception apparatus generates and transmits a response frame according to the procedure of FIG.

  As in the first embodiment, the optical transmitter / receiver of the request frame transmission source that has received the response frame sends the transmission source IP address, transmission source MAC address, and transmission / reception wavelength information in the preamble area to the correspondence table 231 as in the first embodiment. I remember. However, in this embodiment, since request frames are transmitted at all transmittable wavelengths, response frames can be received at multiple wavelengths when communication is possible with a destination optical transceiver at multiple wavelengths. There is sex. If response frames are received at a plurality of wavelengths, the highest priority wavelength received is stored in the correspondence table 231 according to the procedure of FIG.

  By using this embodiment, even when the number of wavelengths is large, the transmission destination MAC address and the transmission / reception wavelength can be acquired within a certain time.

  According to the present invention, in an optical communication system in which a wavelength that can be communicated is different for each optical transmission / reception apparatus in a network using a plurality of wavelengths, the information on the MAC address and transmission / reception wavelength of the optical transmission / reception apparatus of the communication partner is efficiently obtained. Since it can be acquired, it can be used to improve the service quality of the optical communication system.

The block diagram of the Ethernet frame used in a present Example. 1 is a basic configuration diagram of an optical transmission / reception apparatus used in the present embodiment. The flowchart which shows the ARP request | requirement processing procedure in a 1st Example. The flowchart which shows the ARP request | requirement frame reception process procedure in a 1st Example. The flowchart which shows the ARP request | requirement process sequence in 2nd Example. The flowchart which shows the correspondence table update process sequence in a 2nd Example. The flowchart for demonstrating a prior art. The flowchart which shows the ARP request | requirement processing procedure of a prior art. The flowchart which shows the ARP request frame reception processing procedure of a prior art.

Explanation of symbols

101 Preamble 102 Transmission destination MAC address 103 Transmission source MAC address 104 Frame type 105 Data 106 FCS
111 Transmission / reception wavelength 112 Error detection 201, 261-26N Receiver 202 Header reading unit 203 Transmission buffer memory 204 Output control unit 205 Switch 206 Wavelength multiplexer 211-11N, 259 Transmitter 230 ARP control unit 231 Correspondence table 256 Wavelength demultiplexing 257 Receive buffer memory 258 Frame identification unit 290 Optical transmission line

Claims (5)

A plurality of optical transmission / reception devices and an optical transmission line connecting the plurality of optical transmission / reception devices; the optical transmission / reception device transmits and receives at a plurality of wavelengths; In the transmitted / received wavelength information acquisition method,
When obtaining a MAC (Media Access Control) address from an IP (Internet Protocol) address of an optical transmission / reception apparatus of a communication partner by ARP (Address Resolution Protocol), a predetermined order for each wavelength that can be transmitted by the own optical transmission / reception apparatus A transmission / reception wavelength information acquisition method comprising: storing a request frame by transmitting a wavelength at which a response frame is first returned as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner. A plurality of optical transmission / reception devices and an optical transmission line connecting the plurality of optical transmission / reception devices; the optical transmission / reception device transmits and receives at a plurality of wavelengths; In the transmitted / received wavelength information acquisition method,
When acquiring the MAC address from the IP address of the communication partner optical transmitter / receiver by ARP, the request frame is transmitted at a plurality of wavelengths that can be transmitted by the own optical transmitter / receiver, and the response frame is determined in advance. A method of acquiring transmission / reception wavelength information, comprising: storing a highest wavelength in the priority order as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner. A plurality of optical transmission / reception devices and an optical transmission line connecting the plurality of optical transmission / reception devices; the optical transmission / reception device transmits and receives at a plurality of wavelengths; In the optical transceiver
Information storage means for storing an IP address, a MAC address, and a transmission / reception wavelength for another optical transmission / reception device;
Information retrieval means for retrieving whether there is information that matches the IP address of the optical transceiver of the communication partner in the information stored by the information storage means;
A transmission / reception wavelength information acquisition means for inquiring of the communication partner optical transmission / reception apparatus and acquiring information when there is no information matching the IP address of the communication counterpart optical transmission / reception apparatus in the information storage means; Prepared ,
The transmission / reception wavelength information acquisition means transmits a request frame in a predetermined order for each wavelength that can be transmitted by the own optical transmission / reception apparatus when acquiring the MAC address from the IP address of the optical transmission / reception apparatus of the communication partner by ARP. An optical transmission / reception apparatus comprising means for storing a wavelength at which a response frame is returned first as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner . A plurality of optical transmission / reception devices and an optical transmission line connecting the plurality of optical transmission / reception devices; the optical transmission / reception device transmits and receives at a plurality of wavelengths; In the optical transceiver
Information storage means for storing an IP address, a MAC address, and a transmission / reception wavelength for another optical transmission / reception device;
Information retrieval means for retrieving whether there is information that matches the IP address of the optical transceiver of the communication partner in the information stored by the information storage means;
Transmission / reception wavelength information acquisition means for making an inquiry to the communication partner optical transmitter / receiver and acquiring information when there is no information matching the IP address of the communication partner optical transmitter / receiver in the information storage means;
With
The transmission / reception wavelength information acquisition means transmits a request frame at a plurality of wavelengths that can be transmitted by the own optical transmission / reception device when acquiring the MAC address from the IP address of the optical transmission / reception device of the communication partner by ARP. A unit for storing the highest wavelength among the returned wavelengths in a predetermined priority order as a transmission / reception wavelength used for communication with the optical transmission / reception apparatus of the communication partner;
An optical transceiver characterized by that . An optical communication system comprising the optical transmission / reception device according to claim 3 and an optical transmission path connecting the plurality of optical transmission / reception devices.

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