JP4951460B2 - Transfer device and optical network system - Google Patents

Description

  The present invention relates to a transfer apparatus and an optical network system, and more particularly, to a transfer apparatus and an optical network system that perform high-speed transfer without changing an optical signal into an electrical signal.

In recent years, it has been put into practical use in core networks to transfer an optical signal as it is without converting the optical signal into an electrical signal based on the wavelength of the light using OXC (Optical cross Connect) technology. For switching light, a matrix switch (see Non-Patent Document 1) or MEMS (Micro)
Electro Mechanical
Systems) mirror switches are used. As an advantage of transferring an optical signal as it is, first, the overhead of conversion from an optical signal to an electric signal and from an electric signal to an optical signal is eliminated, so that high-speed transfer and low-delay transfer are possible. Furthermore, since it is not necessary to interpret the upper protocol in the relay device, the transfer speed is not affected by the performance of the semiconductor technology such as the processor and memory, and the performance of the OS.

  Further, as an optical path setting method for these OXC apparatuses, standardization of GMPLS (Generalized Multi-Protocol Label Switching: see Non-Patent Document 2) technology is being promoted. A core network using GMPLS is divided into a control plane for setting an optical path and a data plane for transferring data. Since such a core network has an autonomous control function, it is said that the operation can be simplified, and when a failure occurs on a relay device or a route, the route can be switched at high speed, thereby improving the reliability of the network. In addition, in order to perform transfer control using a finite wavelength, development of a wavelength allocation / conversion method (see Patent Document 1 and Patent Document 2) and optical burst switch technology (see Non-Patent Document 3) are recommended. It has been.

  Furthermore, research on optical packet routers (see Patent Document 3) that enables transfer in units of packets as optical signals without concern for wavelength resources is being conducted. A conventional router has a memory for buffering packets, reads packet information, and performs transfer control and collision avoidance. On the other hand, an optical packet router has a transfer control function equivalent to that of a conventional router and can perform high-speed transfer by combining a delay line and an optical switch in place of this memory.

On the other hand, in an access network, an optical fiber has been installed up to a general user by a PON (Passive Optical Network) technology. However, although the packet transmission medium is light, an optical signal is converted into an electrical signal in a relay device or a LAN (Local Area Network).
“Compact 16 × 16 optical matrix switch using PLC” [online], NTT Photonics Laboratories, http: // www. phlab. ecl. ntt. co. jp / theme / 2006/2006 — 11 — 02. pdf Shiomoto, H., “GMPLS Overview and Standardization Trends”, [online], NTT Technical Journal, http: // www. ntt. co. jp / journal / 4044 / files / jn200404060. pdf “Activity Report of Optical Burst PJ”, [online], National Institute of Information and Communications Technology, http: // www. khn-openlab. jp / symposium / 2004 / report / 1_3. pdf JP 2006-287778 A JP 2005-286383 A JP 2007-20017 A

  In the access network, in order to transfer an optical signal as it is without converting it into an electrical signal as in the core network, when the above-mentioned OXC device is used, the user terminal must first implement the GMPLS technology. Further, when the number of user terminals increases, the data for transfer control also increases, so that the control plane may be congested and normal transfer may not be performed on the data plane.

  In order to avoid the above-mentioned problem in the OXC device, the above-mentioned optical packet router is used as the edge transfer device closest to the user terminal side, and the optical packet router terminates GMPLS, thereby suppressing an increase in transfer control data. . However, in this case, the number of optical packet routers that require advanced technology increases, and the cost for network construction increases.

  In view of the above points, the present invention reduces the burden on the user terminal and the cost of network construction by using relatively simple means compared to the means performed in the core network, and converts optical signals into electrical signals in the access network. It is an object of the present invention to provide a transfer apparatus and an optical network system that realize transfer without changing an optical signal. Furthermore, the present invention provides a transfer apparatus and an optical access network system that enable communication with all optical signals as they are end-to-end of a user terminal by providing compatibility with a core network. One of the purposes.

  By connecting to a core network that transfers optical signals as they are, the present invention allows all communication between user terminals via the core network to remain as optical signals, enabling high-speed transfer and increasing traffic on the network in the future. One of the purposes is to make it compatible. The present invention also provides high-quality services such as IP phone, videophone, and real-time broadcasting that require low-delay transfer when the communication with a destination is continued, reducing the delay in the transfer device. One of the purposes is to do.

  A function to control the transmission wavelength based on the destination address based on the table at the time of transmission to the user terminal line interface, and to set the switch according to the wavelength notified from the transfer device connected to the user terminal at the time of reception. To have. The transfer apparatus has a function of setting a switch based on a table for assigning and managing received wavelengths of user terminals.

  When the user terminal and the transfer apparatus are connected by an optical cable and the link up of layer 1 is triggered, the user terminal notifies the transfer apparatus of the address set in the own user terminal using the reserved control wavelength. From the notification, the transfer device grasps the address of the user terminal connected to the interface, manages it in a table, assigns a reception wavelength for each user terminal, and notifies the user terminal using a pre-reserved control wavelength. . In the user terminal, a switch (or selector) is set so as to receive at that wavelength. The reception preparation of the user terminal is completed by the above procedure.

  When the user terminal sends data to a certain destination, the transfer device is inquired of the wavelength corresponding to the destination address using the control wavelength. The transfer device grasps the address of the user terminal when the user terminal is connected as described above, and manages the wavelength corresponding to the address in a table. Based on the table, the wavelength corresponding to the inquired address is notified to the user terminal using the control wavelength. At the same time, when the transfer device receives the signal of the wavelength notified from the inquiring user terminal, it sets the switch so that the signal of the wavelength can be transferred to the corresponding interface. The user terminal that has received the notification manages the destination address and the wavelength in the correspondence table. The user terminal controls the transmission wavelength based on the table and transmits data. When data is input to the transfer device, the switch is set at the time of the inquiry in the transfer device, so that the optical signal is transferred as it is. With the above procedure, the optical signal from the user terminal can be transferred as it is.

  In the case of communication via the core network, the core network is configured by an optical packet router, the optical packet router and the transfer device are connected, and the transfer device and the user terminal are connected. When the optical packet router and the transfer device are connected and the link up of layer 1 is triggered, the optical packet router notifies the transfer device of the address and the router using the reserved control wavelength. The transfer apparatus that has received the notification assigns a wavelength addressed to the optical packet router, and records in the table that the router is connected to the address. Similarly to the above, when the user terminal is connected to the transfer apparatus and the transfer apparatus receives an address notification from the user terminal upon the link up of layer 1, the wavelength is assigned, the table is updated, and the optical packet router is connected. In this case, the table information is notified to the optical packet router using the control wavelength. The optical packet router can grasp the address and wavelength of the user terminal connected to the end of the connected transfer device from the table information. The optical packet router manages a table in which addresses and wavelengths are associated with each other, and updates the table every time table information is received from the transfer apparatus.

  When there is no address in the table managed by the transfer apparatus at the time of inquiry from the user terminal, the wavelength corresponding to the address registered as the address of the optical packet router is notified to the user terminal. At the same time, the transfer device sets the switch so that when the wavelength is received from the user terminal, it can be transferred to the interface to which the optical packet router is connected. When the user terminal transmits data at the wavelength addressed to the router and is input to the transfer device, it is transferred to the optical packet router as an optical signal. In the optical packet router that has received the data, the destination address given to the data is read, converted to the corresponding wavelength on the management table, and transferred. With the above procedure, it is possible to transfer data as an optical signal from the user terminal to the transfer device, from the transfer device to the optical packet router, from the optical packet router to another transfer device, and from another transfer device to the user terminal.

  In addition, an expiration date is set for the transmission wavelength assigned to the user terminal by the transfer device, the expiration date is monitored by each of the user terminal and the transfer device, and if the user terminal wants to transmit data continuously, the expiration date expires. The expiration date is extended by inquiring the transmission wavelength again before. When the user terminal does not need to transmit data continuously, the table is initialized at the user terminal upon the expiration of the expiration date, and the corresponding path setting of the switch is canceled at the transfer device. This makes it possible to dynamically cancel a useless switch path setting that is not used by the transfer apparatus.

According to the first solution of the present invention,
A transfer device for transferring an optical signal from a user terminal as an optical signal,
A plurality of interfaces for communicating with the first and second user terminals;
A control unit that assigns a communication wavelength for the user terminal to receive a signal;
An interface identifier, an address of the user terminal, a storage area for recording assigned communication wavelength information,
A switch that transfers an optical signal received from one of the interfaces to the other interface as an optical signal according to the setting by the control unit;
With
The controller is
Receiving the address of the second user terminal from the second user terminal;
A communication wavelength for the second user terminal to receive a signal is assigned to the second user terminal, the interface identifier to which the second user terminal is connected, the received address, and the assigned communication wavelength information Is recorded in the storage area,
Receiving an inquiry including the address of the second user terminal, which is transmitted from the first user terminal when the first user terminal sends data to the address of the second user terminal;
Obtaining a corresponding interface identifier and communication wavelength information by referring to the storage area based on the address included in the inquiry;
Setting the switch to transfer the optical signal of the communication wavelength from the interface to which the first user terminal is connected to the interface indicated by the acquired interface identifier as it is,
Notifying the first user terminal of the acquired communication wavelength information,
Provided is a transfer device in which an optical signal of the communication wavelength transmitted from a first user terminal according to the notification is transferred as an optical signal to the interface to which a second user terminal is connected by the set switch. The

According to the second solution of the present invention,
A storage area for recording communication wavelength information corresponding to the destination address; reading the communication wavelength information with reference to the storage area based on the destination address of the received optical signal; and determining the wavelength of the received optical signal An optical packet router that converts to a communication wavelength;
A first transfer device having a first switch for transferring an optical signal and communicating with the first user terminal and the optical packet router;
A second switch for transferring an optical signal, comprising a second user terminal and a second transfer device for communicating with the optical packet router;
The first transfer device includes:
Assigning a first communication wavelength to the optical packet router, recording the assigned first communication wavelength information;
Receiving an inquiry including the address of the second user terminal, which is transmitted from the first user terminal when the first user terminal sends data to the address of the second user terminal;
Since the address included in the inquiry is not recorded, the first communication wavelength information assigned to the optical packet router is notified to the first user terminal,
Setting the first switch to transfer the optical signal of the first communication wavelength from the first user terminal to the optical packet router without changing the optical signal;
The second transfer device includes:
Receiving the address of the second user terminal from the second user terminal;
Assigning a second communication wavelength for the second user terminal to receive a signal to the second user terminal;
Transmitting the received second user terminal address and the assigned second communication wavelength information to the optical packet router;
Setting the second switch to transfer the optical signal of the second communication wavelength from the optical packet router to the second user terminal as an optical signal;
The optical packet router stores the address of the second user terminal received from the second transfer device in association with the second communication wavelength information in the storage area,
The optical signal having the first communication wavelength, which is transmitted from the first user terminal and having the address of the second user terminal as the destination address, is transferred as the optical signal to the optical packet router by the set first switch. And
The packet router refers to the storage area based on the destination address of the received optical signal, acquires the corresponding second communication wavelength, and converts the wavelength of the received optical signal into the acquired second communication wavelength. Transfer to the second transfer device,
There is provided an optical network system in which an optical signal of the second communication wavelength is transferred as it is to a second user terminal by the set second switch.

  According to the present invention, a relatively simple means is used than the means performed in the core network to reduce the burden on the user terminal and the cost of network construction, and in the access network, the optical signal is not converted into an electrical signal. It is possible to provide an optical network system that realizes the transfer as it is. Furthermore, according to the present invention, by providing compatibility with the core network, it is possible to provide an access network system that enables communication with all optical signals as they are at the end to end of the user terminal.

  According to the present invention, by connecting to the core network that transfers the optical signal as it is, all communication between the user terminals via the core network remains as an optical signal, so that high-speed transfer is possible and the network on the future It can cope with traffic increase. In addition, according to the present invention, when continuously communicating with a certain destination, the delay in the transfer device can be reduced as compared with the conventional one. Therefore, services such as IP phone, video phone, and real-time broadcasting that require low delay transfer are high. It becomes possible to provide with quality.

Hereinafter, the present embodiment will be described with reference to the drawings as appropriate.
1. System Configuration FIG. 1 shows a network configuration diagram of the present embodiment.
The optical network system includes an optical packet router (200 to 203) in a core network (CN) and a transfer device (100) in an access network (AN). In the access network (AN-A, AN-B), for example, user terminals (10-A1 to 10-B3) are connected to transfer devices (100, 101). The user terminals (10-A1 to 10-B3) are connected to the core network (CN) via the transfer devices (100, 101).

FIG. 2 shows a configuration example of the line unit of the user terminal.
The line unit of the user terminal (10) includes, for example, a line control unit (10-1), a data light receiving unit (10-2), a control light receiving unit (10-3), a switch (10-4), and an optical transmission. Section (10-5), demultiplexing section (10-6), multiplexing / demultiplexing section (10-7), and memory (10-20). Further, it has a switch control bus (10-9), an internal bus (10-19), and a transmission wavelength control bus (10-8). The memory (10-20) has a first table (storage area, 10-21).

  When the optical signal (10-11) is received from the transfer device (100, 101), the received signal (10-12) is extracted by the demultiplexing unit (10-7). The received signal (10-12) is further divided into a data optical signal (10-13) and a control optical signal (10-14) by a demultiplexing unit (10-6). The control light receiver (10-3) converts the control light signal (10-14) into an electric signal (10-10) and transfers it to the line controller (10-1). The line control unit (10-1) recognizes the wavelength addressed to itself based on the information, and controls the switch (10-9) via the switch control bus (10-9), so that the optical signal addressed to itself is transmitted. (10-15) is transferred to the data optical receiver (10-2). The data optical receiving unit (10-2) converts the optical signal into an electric signal (10-16) and transfers it to the user terminal.

  At the time of transmission from the user terminal, the IP address is notified from the user terminal through the internal bus (10-19) to the line control unit (10-1). The line control unit controls the optical transmission unit (10-5) via the transmission wavelength control bus (10-18) based on the first table (10-21) stored in the memory (10-20). To do. The optical transmitter (10-5) converts the electrical signal (10-17) into an optical signal (10-18). The optical signal (10-18) is multiplexed by the multiplexing unit (10-7) and transmitted to the transfer device (100, 101) (10-11).

  In this embodiment, it is assumed that the user terminal (10-A1 to 10-B3) and the transfer device (100, 101) are connected by a single-core fiber and use different wavelengths for transmission and reception. When connected by a two-core fiber, the same wavelength can be used for transmission and reception, and the multiplexing / demultiplexing unit (10-7) becomes unnecessary.

FIG. 3 shows a configuration example of the transfer apparatus.
The transfer device includes, for example, a multiplexing / demultiplexing unit (100-1), a switch (100-2), a control light receiving unit (100-3), a control light transmitting unit (100-4), and a control. Part (100-5) and a memory (100-13). The memory (100-13) has a second table (storage area, 100-14).

  The control optical signal (100-6) from the user terminals (10-A1 to 10-B3) is converted into the data optical signal (100-7) and the control optical signal (100-8) by the demultiplexing unit (100-1). It is demultiplexed. The control light signal (100-8) is converted into an electric signal (100-10) by the control light receiver (100-3) and transferred to the controller (100-5). Conversely, when the control light signal (100-6) is transmitted from the transfer device (100, 101) to the user terminal (10-A1 to 10-B3), the electric signal (100-) is transmitted from the control unit (100-5). 11) is converted into an optical signal (100-9) by the control light transmission unit (100-4), and is multiplexed and transmitted by the multiplexing unit (100-1).

  The control unit (100-5) sets the switch (100-2) with the control bus (100-12) based on the second table (100-14) stored in the memory (100-13), and the data light The signal (100-7) is switched, for example, for each wavelength based on the setting. There is no difference in configuration for each interface. The switch (100-2) can be composed of a matrix switch used in OXC, for example.

FIG. 4 shows a schematic configuration diagram of the optical packet router (200 to 203).
In addition, about the detailed structure of an optical packet router, since an appropriate thing can be used, detailed description is abbreviate | omitted and the location relevant to this Embodiment is demonstrated. When the control optical signal (200-4) is received from the transfer device (100, 101), the optical signal processing unit (200-1) converts it into an electrical signal, reads the data, and stores the information in the memory (200-2). The third table (200-3) stored in () is updated. When another optical signal (200-4) is received, the optical signal processing unit (200-1) converts the wavelength based on the information in the third table (storage area, 200-3) and transmits it. . The operation will be described later.

2. Communication between User Terminals in LAN 2.1 System Configuration Example FIG. 5 shows a case where data is transmitted from a user terminal (10-A1) in a LAN to a user terminal (10-A3) via a transfer device (100). The network configuration is shown.
IP addresses 192.168.1.1 to 3 are set in advance in the user terminals (10-A1 to 10-A3). User terminals (10-A1 to 10-A3) are connected to the interfaces (IF # 1 to IF3) of the transfer apparatus (100), respectively.

FIG. 6 shows an example of the second table (100-14) held by the control unit (100-5) of the transfer apparatus (100, 101).
The second table (100-14) corresponds to the interface number (IF #, 100-14-1), wavelength information (communication wavelength information, 100-14-2), and IP address (100-14-3). Is remembered. The transfer device (100, 101) grasps which interface has which user terminal (10-A1 to 10-B3) has which IP address (100-14-3), and the user terminal (10-A1 to 10-). In response to the destination inquiry from B3), the wavelength (100-14-2) corresponding to the destination IP address (100-14-3) based on the second table (100-14) is set to the user terminal (10-A1). To 10-B3). The switch (100-2) is set based on the second table (100-14).

FIG. 7 shows an example of the first table (10-21) held by the user terminals (10-A1 to 10-B3).
The first table (10-21) stores the transmission wavelength (10-21-2) for sending data to the destination corresponding to the destination IP address (10-21-1). The first table (10-21) is updated based on information from the transfer devices (100, 101), and the transmission wavelength (10-21-2) corresponding to the destination IP address (10-21-1) is transmitted at the time of transmission. ) To send.

2.2 Operation FIG. 9 shows a sequence diagram of user terminal communication in a LAN.
For example, the user terminal (10-A1 to 10-A3) connects a cable to the transfer device (100), transmits data from the user terminal (10-A1) to the user terminal (10-A3), and then the user terminal (10 An operation sequence until the link down between A1) and the transfer apparatus (100) is shown. In the following description, the wavelengths λm1 and λm2 are transmitted and received between the user terminal (10-A1, 10-B1) and the transfer device (100, 101), and between the transfer device (100, 101) and the optical packet router (200). The wavelength for the control optical signal (control wavelength) determined in advance for exchanging the wavelength information.

  In the LAN configuration shown in FIG. 5, communication between user terminals will be described with reference to the sequence diagram of FIG. The user terminal (10-A1) is connected to the interface # 1 of the transfer apparatus (100) with an optical fiber, and the link up of layer 1 is performed (SQ1-1). Similarly, the other user terminals (10-A2, 10-A3) are connected to the interfaces # 2 and # 3 of the transfer apparatus (100) and are linked up at layer 1 (SQ1-2, SQ1-3). After the link up, the line control unit (10-1) of the user terminal (10-A1 to 10-A3) controls the optical transmission unit (10-5) to set the wavelength to a predetermined wavelength λm1, and the user terminal From (10-A1 to 10-A3), the IP address (192.168.1.1 to 3) set in the user terminal (10-A1 to 10-A3) is transferred using the wavelength λm1. (100) is notified (SQ1-4 to SQ1-6).

  In the transfer device (100) that has received the notification, the optical signal having the wavelength λm1 is demultiplexed by the transmission / reception optical signal multiplexing / demultiplexing unit (100-1) and converted into an electrical signal by the control light receiving unit (100-3). Converted. The control unit (100-5) recognizes how many user IP addresses are connected to which interface from the converted data, assigns a wavelength (communication wavelength) to each IP address, and stores the memory (100- The IF #, the assigned wavelength, and the received IP address are recorded in the second table (100-14) stored in 13) (SQ1-7, FIG. 6).

  The allocated wavelength (100-14-2) information is converted into an optical signal by the control light transmission unit (100-4) and multiplexed by the transmission / reception optical signal multiplexing / demultiplexing unit (100-1). (10-A1 to 10-A3) is notified using the wavelength λm2 (SQ1-8 to SQ1-10). In the user terminals (10-A1 to 10-A3) that have received the notification, the optical signal of wavelength λm2 is first demultiplexed by the transmission / reception optical signal multiplexing / demultiplexing unit (10-7), and the received optical signal component is further demultiplexed. The signal is demultiplexed by the wave unit (10-6) and converted into an electric signal by the control light receiving unit (10-3). From the data, the line control unit (10-1) recognizes the wavelength (100-14-2) received by the user terminals (10-A1 to 10-A3), controls the switch (10-4), and determines the wavelength. The optical signal (100-14-2) can be received (SQ1-11 to SQ1-13). For example, the notified wavelength light is input to the data light receiving unit (10-2). The user terminal (10-A3) can receive a signal of wavelength λa3.

  Next, when a user terminal (first user terminal, 10-A1) transmits data to a user terminal (second user terminal, 10-A3) having an IP address of 192.168.1.3, which wavelength is used. If it is used, an inquiry is made to the transfer apparatus (100) using the wavelength λm1 in order to know whether the data will arrive (SQ1-14). This inquiry includes, for example, the IP address 192.168.1.3 of the user terminal (10-A3). In the transfer device (100) that has received the inquiry, the control unit (10-5) refers to the first table (10-21) (SQ1-15), and the IP address (100-14-3) 192.168. The wavelength information (100-14-2) λa3 corresponding to 1.3 is acquired and notified to the user terminal (10-A1) using the wavelength λm2 (SQ1-16). In the transfer device (100), when the optical signal having the wavelength λa3 is received from IF # 1, the control unit (100-5) sets the switch (100-2) so that the signal can be transferred to IF # 3 (SQ1- 17). In the user terminal (10-A1) that has received the transmission wavelength notification (SQ1-16), the line control unit (10-1) updates the first table (10-21) (SQ1-18, FIG. 7). For example, the received wavelength information λa3 corresponding to the IP address is stored.

  The user terminal (10-A1) refers to the updated first table (10-21), and the control unit (10-21) controls the optical transmission unit (10-5) to set the transmission wavelength to λa3. . Thus, the electrical signal (10-17) from the user terminal is transmitted as an optical signal having the wavelength λa3 (SQ1-19). In the transfer apparatus (100), the optical signal having the wavelength λa3 input to the interface # 1 is first demultiplexed by the transmission / reception optical signal multiplexing / demultiplexing unit (100-1) and enters the switch (100-2). Since the switch (100-2) is set in advance to output to the interface # 3 (SQ1-17), it is multiplexed by the transmission / reception optical signal multiplexing / demultiplexing unit (100-1) of IF # 3. The data is transferred to the user terminal (10-A3) (SQ-19).

  In addition, in response to the layer 1 link down (SQ1-20) between the user terminal (10-A1) and the transfer apparatus (100), the user terminal (10-A1) has a first wavelength table for transmission (10-21). Is initialized (SQ1-22), and the transfer apparatus (100) deletes the information of # 1 from IF # (100-14-1) from the second table (100-14) (SQ1-21). Further, the setting of the switch (100-2) which has been set in the transfer apparatus (100) is canceled (SQ1-23).

3. 3. Communication between user terminals across sub-networks 3.1 System configuration example FIG. 8 shows that a user terminal (10-A1) belonging to a sub-network A of 192.168.1.0 is connected to a 192.168.2.0 sub-network B. The network structure in the case of transmitting data to the user terminal (10-B1) which belongs to is shown.

  FIG. 8 is a simplified version of FIG. 1 for ease of explanation. In the subnetwork A, the user terminal (10-A1) having the IP address 192.168.1.1 is connected to the interface # 1 of the transfer apparatus (100), and the interface # 4 is the IP address 192 of the optical packet router (200). .168.1.200 is connected to the set port. Similarly, in the subnetwork B, the user terminal (10-B1) having the IP address 192.168.2.1 is connected to the interface # 1 of the transfer apparatus (101), and the interface # 4 is the IP of the optical packet router (200). It is connected to the port for which the address 192.168.2.200 is set.

10 and 13 show an example of the second table (100-14) of the transfer device (100, 101) in the example of FIG. The configuration of the table is the same as in FIG.
FIG. 11 shows an example of the first table (10-21) of the user terminal (10-A1) in the example of FIG. The configuration of the first table (10-21) is the same as that in FIG.
FIG. 12 shows an example of the third table (200-3) of the optical packet router (200) in the example of FIG. A destination IP address (200-3-1), a transmission wavelength (200-3-2) corresponding to the IP address, and a connected IF # (200-3-3) are stored correspondingly.

3.2 Operation FIG. 14 shows a sequence diagram of communication between user terminals across sub-networks.
For example, the user terminal (10-A1, 10-B1) and the optical packet router (200) are connected to the transfer apparatus (100, 101) by a cable, and the user terminal (10-A1) to the user terminal (10-B1). This is an operation sequence until data is transmitted and the link between the user terminal (10-A1) and the transfer apparatus (100) is down.

  In the network configuration shown in FIG. 8, communication between user terminals will be described with reference to the sequence diagram of FIG. When the optical packet router (200) and the transfer device (100, 101) are connected and link-up is performed at layer 1 (SQ2-1, SQ2-2), the optical packet router (200) is connected to the optical signal processing unit (200-1). The transfer device (100, 101) is notified of the IP address and the router using a predetermined wavelength λm1 (SQ2-3, SQ2-4). The transfer apparatuses (100, 101) that have received the notification update the second table (100-14) (SQ2-5, SQ2-6). At this time, the transfer device (100, 101) assigns the wavelengths λra1 and λrb1 addressed to the optical packet router, and stores the IP address of the router in the second table (100-14) (FIG. 10- (1), FIG. 13- (1)).

  Next, when the user terminal (10-A1, 10-B1) is connected to the transfer apparatus (100, 101), the user terminal (10-) is triggered by the link-up (SQ2-7, SQ2-8) of layer 1 A1, 10-B1) notifies the IP address using the wavelength λm1 (SQ2-9, SQ2-10). The transfer apparatuses (100, 101) that have received the notification assign the wavelengths λa1 and λb1 to the user terminals (10-A1, 10-B1), and update the second table (100-14) (SQ2-11, FIG. 10). -(2), SQ2-12, FIG. 13- (2)), the wavelength (100-14-2) is notified to the user terminal using the wavelength λm2 (SQ2-13, SQ2-14). In addition, information on the wavelength (100-14-2) corresponding to the IP address (100-14-3) of the user terminal (10-A1, 10-B1) connected to the subordinate is transmitted to the optical packet router (200). (SQ2-15, SQ2-16). Further, at this time, the transfer apparatus (100, 101) transmits the optical signals of wavelengths λra1 and λrb1 from the user terminal (10-A1, 10-B1) to the optical packet router (200) and from the optical packet router (200). The switch (100-2) is set so that the optical signals of the wavelengths λa1 and λb1 are transferred to the user terminals (10-A1, 10-B1).

  On the other hand, the user terminal (10-A1, 10-B1) that has received the reception wavelength notification (SQ2-13, SQ2-14) sets the switch (10-4) so that it can receive at that wavelength (SQ2-19). , SQ2-20). The optical packet router (200) that has received the table information (SQ2-15, SQ2-16) has a third table (200-3) in which the optical signal processing unit (200-1) is stored in the memory (200-2). ) Is updated (SQ2-21, FIG. 12). For example, the optical packet router (200) stores the received IP address and wavelength of the terminal in correspondence with IF # (FIG. 12).

  Next, when the user terminal (10-A1) transmits data to the IP address 192.168.2.1 of the user terminal (10-B1), the user terminal (10-A1) first uses the wavelength λm1. Then, the transmission wavelength is inquired to the transfer apparatus (100) (SQ2-22). This inquiry includes, for example, the IP address 192.168.2.1 of the user terminal (10-B1). The transfer device (100) refers to the second table (100-14) (SQ2-2, FIG. 10), and if the corresponding IP address is not in the second table (100-14), it is stored as a router. The user terminal (10-A1) is notified using the wavelength λm2 with the existing wavelength (λra1) as the transmission wavelength (SQ2-24). The user terminal (10-A1) that has received the notification recognizes that the transmission wavelength corresponding to the IP address 192.168.2.1 is λra1, and updates the first table (10-21) (SQ2-25, FIG. 11).

  When the user terminal (10-A1) transmits data at the wavelength (λra1) recorded in the first table (10-21) (SQ2-26), the transfer device (100) directly sends it to the optical packet router (200). Transferred. When the optical packet router (200) receives the data, the optical signal processing unit (200-1) reads the destination IP address from the data, refers to the third table (200-3) (SQ2-27), and the corresponding wavelength ( The wavelength is converted to [lambda] b1) and transmitted to the transfer apparatus (101) (SQ2-28). When the transfer device (101) receives the data of the wavelength λb1, since the switch has already been set as described above, it is directly transferred to the user terminal (10-b1).

  In response to the layer 1 link down (SQ2-29) between the user terminal (10-A1) and the transfer apparatus (100), the user terminal (10-A1) initializes the first table (10-21). The transfer device (100) deletes the information corresponding to the interface # 1 from the second table (100-14) (SQ2-31). The transfer device (100) transmits the updated table information to the optical packet router (200) using the wavelength λm2 (SQ2-32), and cancels the setting of the switch (100-2) (SQ2-34). The optical packet router (200) that has received the table information determines that the user terminal (10-A1) has been disconnected from the subordinates of the transfer device (100), and the user terminal (10-) from the third table (200-3). The information of A1) is deleted (SQ2-33). At this time, not only the optical packet router (200) but also the user terminals (10A-1 to 10-B3) are connected to the transfer apparatus (100).

4). Canceling Switch Path Setting of Transfer Device 4.1 System Configuration Example FIG. 15 shows an example of a switch path setting table managed by the transfer device (100). The switch path setting table can be stored in the memory (100-13).
The information includes a path (100-14-4) indicating which interface is connected to which interface, a wavelength (100-14-5) of a signal passing through the path, and an expiration date of the path (or wavelength) ( 100-14-6) are stored correspondingly.
FIG. 16 shows an example of a first table (10-21) with an expiration date managed by the user terminal (10-A1). An expiration date (10-21-3) is added to the configuration of FIG.

4.2 Operation FIG. 17 shows a sequence diagram for canceling the switch path setting of the transfer apparatus.
For example, the transmission wavelength of the user terminal (10-A1) that is no longer used is deleted from the first table (10-21) managed by the user terminal (10-A1), and the switch (100- This is an operation sequence for canceling the setting of 2). In the above example, since the switch of the transfer device is set in advance, when the terminal tries to communicate with another terminal, it is necessary to cancel the switch setting.

  In FIG. 5, the transmission wavelength of the user terminal (10-A1) that is no longer used is deleted from the first table (10-21) managed by the user terminal (10-A1), and at the same time the switch of the transfer apparatus (100) The operation for canceling the setting of (100-2) will be described with reference to the sequence diagram of FIG.

  Since the link-up of layer 1 to the completion of reception setting of the user terminals (10-A1 to 10-A3) (SQ3-1 to SQ3-13) are the same as those in FIG. In order to send data to the IP address 192.168.1.3 of the user terminal (10-A3), the user terminal (10-A1) makes an inquiry to the transfer apparatus using the wavelength λm1 (SQ3-14). The transfer apparatus (100) refers to the second table (100-14) (SQ3-15), and uses the wavelength λm2, and determines the transmission wavelength (for example, λa3) and the expiration date (for example, 100 s) of the transmission wavelength. Notification is made (SQ3-16). Further, the switch (100-2) is set in the same manner as described above (SQ3-17), and the information, wavelength, and expiration date (100-14-6) of the set path are set in the switch path setting table (100-14). Is set (FIG. 15), and the timer is started (SQ3-19).

  On the other hand, the user terminal (10-A1) that received the notification updates the first table (10-21) (SQ3-18), and the expiration date (SQ3-18) notified of the transmission wavelength corresponding to the destination IP address ( 10-21-3) is set (FIG. 16), and the timer is started (SQ3-20). The user terminal (10-A1) transmits data based on the first table (10-21) (SQ3-21). When the user terminal (10-A1) continuously transmits data to the IP address 192.168.1.3 (SQ3-28), the wavelength is set before the timeout (before the expiration date). The transmission wavelength is inquired to the transfer apparatus (100) using λm1 (SQ3-22). In response to the inquiry, the transfer apparatus (100) refers to the second table (100-14) in the same manner as the previous inquiry (SQ3-14) (SQ3-23), and notifies the transmission wavelength and the expiration date using the wavelength λm2. (SQ3-24). At this time, since the switch (100-2) has already been set in the switch path setting table (100-14), the timer is restarted without setting the switch (100-2) (SQ3 -26). The user terminal (10-A1) updates the first table (10-21) (SQ3-25), and restarts the timer as in the transfer device (100) (SQ3-27).

When the user terminal (10-A1) no longer needs to continuously transmit to the IP address 192.168.1.3, the transfer device (100) will trigger a timeout (SQ2-29) unless re-inquiry is made. Then, the setting of the switch (100-2) is canceled and the switch path setting table (100-14) is cleared (SQ3-31). The user terminal (10-A1) also initializes the first table (10-21) with a timeout (SQ3-30) as a trigger (SQ3-32). Thereafter, when the user terminal (10-A1) transmits data to the IP address 192.168.1.3 again, an inquiry is required.
The above-described expiration date has been described by taking communication within the LAN as an example, but the same can be applied to communication across sub-networks.

  In the present embodiment, an example is described in which an IP address is used as a destination address and transfer control is performed using a wavelength. However, an Ethernet (registered trademark) MAC address can also be used as a destination address. In addition, although a user terminal is exemplified as an end device on the network, it is possible to cope with a case where a data transmission / reception device such as a server is used as a data transmission source and reception source.

  The present invention is applicable to, for example, an optical network. In addition, the present invention can be used for an access network that transfers an optical signal as it is.

FIG. 2 is a network configuration diagram (1) of the present embodiment. The figure which shows an example of a structure of the line part of the user terminal of this Embodiment. FIG. 3 is a diagram illustrating an example of a configuration of a transfer device according to an embodiment. The figure which shows a schematic example of a structure of the optical packet router of this Embodiment. The network block diagram (2) of this Embodiment. FIG. 6A is a diagram illustrating an example of a transfer device table. The figure (1) which shows an example of the table of a user terminal. The network block diagram (3) of this Embodiment. The figure which shows the operation | movement sequence in which a user terminal (10-A1) transmits data to a user terminal (10-A3) in the network structure of FIG. FIG. 2B is a diagram illustrating an example of a transfer device table. The figure (2) which shows an example of the table of a user terminal. The figure which shows an example of the table of an optical packet router. FIG. 3C is a diagram illustrating an example of a transfer device table. The figure which shows the operation | movement sequence in which a user terminal (10-A1) transmits data to a user terminal (10-B3) in the network structure of FIG. The figure which shows an example of the switch path setting table of a transfer apparatus. The figure which shows an example of the table with an expiration date of a user terminal. The figure which shows the operation | movement sequence which updates the table which a user terminal (10-A1) manages in the network structure of FIG. 5, and the transfer apparatus (100) cancels | releases switch path setting.

Explanation of symbols

CN: Core network AN-A, AN-B: Access network 10-A1 to 10-B3: User terminal 100, 101: Transfer device 200 to 203: Optical packet router 10-1: Line controller 10-2: Data optical Signal receiving unit 10-3: Control optical signal receiving unit 10-4: Switch 10-5: Optical signal transmitting unit 10-6: Received optical signal demultiplexing unit 10-7: Transmission / reception optical signal multiplexing / demultiplexing unit 10- 8: Optical signal transmitter control bus 10-9: Switch control bus 10-10: Reception control electrical signal 10-11: Transmission / reception optical signal 10-12: Reception optical signal 10-13: Reception data optical signal 10-14: Reception Control optical signal 10-15: Received data optical signal 10-16: Received data electrical signal 10-17: Transmitted data electrical signal 10-18: Transmitted optical signal 10-19: Internal bus 10-20: Memory 10-2 : User terminal table 100-1: Transmission / reception optical signal multiplexing / demultiplexing unit 100-2: Switch 100-3: Control optical signal receiving unit 100-4: Control optical signal transmitting unit 100-5: Control unit 100-6 : Transmission / reception optical signal 100-7: Transmission / reception data optical signal 100-8: Reception control optical signal 100-9: Transmission control optical signal 100-10: Reception control electrical signal 100-11: Transmission control electrical signal 100-12: Switch control Bus 100-13: Memory 100-14: Transfer device table 200-1: Optical signal control unit 200-2: Memory 200-3: Optical packet router table 200-4: Transmission / reception optical signal

Claims (9)

A transfer device for transferring an optical signal from a user terminal as an optical signal,
A plurality of interfaces for communicating with the first and second user terminals;
A control unit that assigns a communication wavelength for the user terminal to receive a signal;
An interface identifier, an address of the user terminal, a storage area for recording assigned communication wavelength information,
A switch that transfers an optical signal received from one of the interfaces to the other interface as an optical signal according to the setting by the control unit;
With
The controller is
Receiving the address of the second user terminal from the second user terminal;
A communication wavelength for the second user terminal to receive a signal is assigned to the second user terminal, the interface identifier to which the second user terminal is connected, the received address, and the assigned communication wavelength information Is recorded in the storage area,
Receiving an inquiry including the address of the second user terminal, which is transmitted from the first user terminal when the first user terminal sends data to the address of the second user terminal;
Obtaining a corresponding interface identifier and communication wavelength information by referring to the storage area based on the address included in the inquiry;
Setting the switch to transfer the optical signal of the communication wavelength from the interface to which the first user terminal is connected to the interface indicated by the acquired interface identifier as it is,
Notifying the first user terminal of the acquired communication wavelength information,
A transfer apparatus in which an optical signal of the communication wavelength transmitted from the first user terminal according to the notification is transferred as the optical signal to the interface to which the second user terminal is connected by the set switch. The plurality of interfaces includes an interface for communicating with an optical packet router;
The controller is
Assigning a second communication wavelength to the optical packet router, recording the assigned second communication wavelength information;
Receiving an inquiry including an address of the third user terminal, which is transmitted from the first user terminal when the first user terminal sends data to the address of the third user terminal;
If the address included in the inquiry is not stored in the storage area, the first user terminal is notified of the second communication wavelength information assigned to the optical packet router,
Setting the switch to transfer the optical signal of the second communication wavelength from the first user terminal to the optical packet router without changing the optical signal;
The optical signal of the second communication wavelength transmitted from the first user terminal is transferred as it is to the optical packet router by the set switch, and the optical packet router transmits the third optical signal belonging to another subnetwork. The transfer device according to claim 1, wherein the transfer device is transferred to the user terminal. The plurality of interfaces includes an interface for communicating with an optical packet router;
The controller is
Receiving the address of the third user terminal from a third user terminal;
A third user terminal is assigned a third communication wavelength for receiving signals by the third user terminal;
Transmitting the received address of the third user terminal and the allocated third communication wavelength information to the optical packet router;
Setting the switch to transfer the optical signal of the third communication wavelength from the optical packet router to the third user terminal as an optical signal,
The optical signal of the third communication wavelength from the user terminal belonging to another subnetwork transferred by the optical packet router is transferred to the third user terminal by the set switch. Transfer device.   The said control part transmits the notification containing this communication wavelength information for setting so that the 2nd user terminal may receive the optical signal of the allocated communication wavelength to a 2nd user terminal. 4. The transfer device according to any one of 3.   The control unit receives a logical address of the second user terminal using a predetermined control wavelength, receives an inquiry from the first user terminal, and transmits a communication wavelength to the first user terminal. The transfer device according to claim 1, which notifies information. Triggered by the disconnection of the first or second user terminal and the first or second transfer device,
The first or second transfer apparatus deletes the disconnected interface identifier, address, and communication wavelength information of the first or second user terminal from the storage area, and cancels the setting of the switch. Item 6. The optical network system according to any one of Items 1 to 5. The controller is
In response to the inquiry from the first user terminal, further notify the expiration date of the acquired communication wavelength information,
By receiving the inquiry again before the expiration date from the first user terminal, the expiration date is extended,
7. The transfer device according to claim 1, wherein when the expiration date expires, the communication wavelength information in the storage area, the corresponding interface identifier and address are deleted, and the setting of the switch is canceled. A storage area for recording communication wavelength information corresponding to the destination address; reading the communication wavelength information with reference to the storage area based on the destination address of the received optical signal; and determining the wavelength of the received optical signal An optical packet router that converts to a communication wavelength;
A first transfer device having a first switch for transferring an optical signal and communicating with the first user terminal and the optical packet router;
A second switch for transferring an optical signal, comprising a second user terminal and a second transfer device for communicating with the optical packet router;
The first transfer device includes:
Assigning a first communication wavelength to the optical packet router, recording the assigned first communication wavelength information;
Receiving an inquiry including the address of the second user terminal, which is transmitted from the first user terminal when the first user terminal sends data to the address of the second user terminal;
Since the address included in the inquiry is not recorded, the first communication wavelength information assigned to the optical packet router is notified to the first user terminal,
Setting the first switch to transfer the optical signal of the first communication wavelength from the first user terminal to the optical packet router without changing the optical signal;
The second transfer device includes:
Receiving the address of the second user terminal from the second user terminal;
Assigning a second communication wavelength for the second user terminal to receive a signal to the second user terminal;
Transmitting the received second user terminal address and the assigned second communication wavelength information to the optical packet router;
Setting the second switch to transfer the optical signal of the second communication wavelength from the optical packet router to the second user terminal as an optical signal;
The optical packet router stores the address of the second user terminal received from the second transfer device in association with the second communication wavelength information in the storage area,
The optical signal having the first communication wavelength, which is transmitted from the first user terminal and having the address of the second user terminal as the destination address, is transferred as the optical signal to the optical packet router by the set first switch. And
The packet router refers to the storage area based on the destination address of the received optical signal, acquires the corresponding second communication wavelength, and converts the wavelength of the received optical signal into the acquired second communication wavelength. Transfer to the second transfer device,
An optical network system in which an optical signal having the second communication wavelength is transferred to a second user terminal as an optical signal by the set second switch. Triggered by the disconnection of the first or second user terminal and the first or second transfer device,
The first or second transfer device deletes the address and communication wavelength information of the disconnected first or second user terminal, notifies the optical packet router of the address and communication wavelength information,
9. The optical network system according to claim 8, wherein the optical packet router deletes the address and communication wavelength information notified from the first or second transfer device from the storage area.

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