JP2012074957A - Signal transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal transfer device which can reduce communication loss when a communication path is switched by a host terminal which detected disconnection of a link.SOLUTION: Port numbers of communication ports are stored while being divided into at least two groups, and transfer processing operation is stopped or started for each port group based on the port number in response to a stop instruction or a start instruction.

Description

  The present invention relates to a signal transfer apparatus that transfers signals between communication terminals.

  Conventionally, a signal transfer device such as a switching hub for transferring a signal between communication terminals such as a personal computer having a communication function is known. In addition, a configuration in which a communication terminal is connected to two or more switching hubs for redundancy and the communication path is switched to another switching hub when a switching hub that is currently establishing a link stops communication is often adopted. . For example, Patent Document 1 discloses a configuration in which a plurality of switching hubs constitute a loop network, and each of the switching hubs autonomously switches a communication path.

JP 2007-174119 A

  However, in the case of the configuration disclosed in Patent Document 1, there may be a problem that the communication disconnection time at the time of switching the communication path by the communication terminal when the communication hub that is currently communicating is stopped is long. In particular, it is considered that the disconnection time becomes longer as the number of communication terminals redundantly connected to the switching hub increases.

  Here, for example, it is assumed that several tens of communication terminals are respectively connected to one communication port of one switching hub and established as a link, and redundantly connected to another switching hub. For example, when the one switching hub stops communication for maintenance or the like, the links are generally disconnected in the order of port numbers. Each of the communication terminals switches the communication path to the other switching hub when detecting a link disconnection with the one switching hub. In this case, for example, after the communication path switching of the communication terminal corresponding to the communication port to be disconnected first is completed, until the communication path switching of the communication terminal corresponding to the communication port to be finally disconnected is completed. A large time lag will occur. If the communication terminal related to the first link disconnection and the communication terminal related to the last link disconnection are communication terminals that frequently communicate with each other, the communication terminals that should frequently communicate with each other will resume mutual communication. There arises a problem that the communication failure time becomes long. As a result, there is a problem that the probability of communication loss at the time of communication switching by a communication terminal that detects a link breakage increases.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a signal transfer device that can reduce a communication loss when a communication path is switched by a communication terminal that detects a link break. .

  The signal transfer device according to the present invention includes a plurality of communication ports, a transfer unit that transfers a signal arriving via one of the communication ports to another one of the communication ports, and the transfer according to a stop command. A communication control unit that stops the transfer processing operation of each communication port for each communication port and starts the transfer processing operation of the transfer unit for each communication port in response to a start command, A storage unit that stores the port numbers of the ports in groups of at least two port groups, and the communication control unit sets the port number for each port group based on the port number according to the stop command or the start command. The transfer processing operation by the transfer unit is stopped or started.

  According to the signal transfer device of the present invention, it is possible to reduce a communication loss when switching a communication path by a communication terminal that detects a link break.

It is a block diagram which shows the signal transfer apparatus which is an Example of this invention with a communication terminal. It is a block diagram which shows the structure of a signal transfer apparatus. It is a figure which shows a response | compatibility with a port number and a connection communication terminal. It is a figure which shows a port group table. It is a sequence diagram which shows operation | movement of each apparatus in a link cutting | disconnection process. It is a sequence diagram which shows operation | movement of each apparatus in a link establishment process.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing signal transfer apparatuses 10-1 and 10-2 according to an embodiment of the present invention. Each of the signal transfer apparatuses 10-1 and 10-2 is connected to the communication terminals 20-1 to 20-m (m is an integer of 2 or more) and 30-1 to 30-n (n is 2 or more) via the link 40. Integer) Controls signal transfer between each. Each of the signal transfer apparatuses 10-1 and 10-2 is, for example, a switching hub. Each of the communication terminals 20-1 to 20-m and 30-1 to 30-n is, for example, a personal computer or a host terminal having a communication function. The link 40 between the signal transfer device 10-2 and each of the communication terminals 20-1 to 20-m and 30-1 to 30-n is formed by a communication network (not shown) such as the Internet. ing. The communication terminals 20-1 to 20-m belong to the port group 51, and the communication terminals 30-1 to 30-n belong to the port group 52. Communication terminals that always communicate with each other or communication terminals with high communication frequency belong to the same port group.

  FIG. 2 is a block diagram showing a configuration of the signal transfer apparatus 10-1. The signal transfer device 10-1 includes a plurality of communication ports 11-p (p is an integer of 2 or more), a transfer unit 12, a table storage unit 13, a command receiving unit 14, and a communication control unit 15. .

  The signal transfer device 10-1 is connected to each of the communication terminals 20-1 to 20-m and 30-1 to 30-n via the communication ports 11-1 to 11-p.

  FIG. 3 is a diagram showing the correspondence between the port number of the signal transfer apparatus 10-1 and the connected communication terminal. For example, the communication terminal 20-1 is connected to the port number 11-1.

  The transfer unit 12 converts a packet signal that has arrived at one of the communication ports 11-1 to 11-p to one communication port (any one of 11-1 to 11-p) corresponding to the destination communication terminal. Have the function of transferring to

  The table storage unit 13 stores a port group table indicating the relationship between the communication terminals 20-1 to 20-m and 30-1 to 30-n and the port groups 51 and 52, and includes a storage medium such as a hard disk. It is.

  FIG. 4 shows a port group table. No. 1-No. Each of m represents an arrangement order within the port group 51. No. 1-No. Each port number of m is the number of a communication port (any one of 11-1 to 11-p) to which one of the communication terminals 20-1 to 20-m belonging to the port group 51 is connected. is there. No. (M + 1) -No. Each of (m + n) represents the arrangement order in the port group 52. No. (M + 1) -No. Each port number of (m + n) is the communication port (any one of 11-1 to 11-p) to which one of the communication terminals 30-1 to 30-n belonging to the port group 52 is connected. Number.

  In the port group table, communication ports that are always subject to mutual transfer or communication ports having a relatively high transfer frequency are grouped into the same port group. As a result, communication terminals that always communicate with each other or communication terminals with a relatively high communication frequency belong to the same port group. Note that the communication control unit 15 can update the port group table in the table storage unit 13 in response to the update command (the following communication port addition command and communication port deletion command).

  The command receiving unit 14 receives a communication stop command, a communication start command, a communication port addition command, and a communication port deletion command. Hereinafter, the communication stop command and the communication start command are referred to as a communication control command. The command receiving unit 14 receives these external commands via a communication network (not shown) such as the Internet.

  The communication control unit 15 establishes a link 40 with each of the communication terminals 20-1 to 20-m and 30-1 to 30-n according to these external commands received by the command receiving unit 14. It has a function of cutting and controlling communication for each communication port. In other words, the communication control unit 15 has a function of stopping and starting the transfer processing operation by the transfer unit 12 for each communication port.

  In the case of a communication stop command, the communication control unit 15 sets the No. in the port group table. The transfer processing operation of the transfer unit 12 is sequentially stopped in the order of the numbers (that is, the order of arrangement of the communication port numbers), and the links 40 are sequentially disconnected. In the case of the port group table shown in FIG. 4, first, the link for each communication terminal belonging to the port group 51 is disconnected, and then the link for each communication terminal belonging to the port group 52 is disconnected. As a result, each communication terminal belonging to the port group 51 is disconnected within a single continuous time zone, and each communication terminal belonging to the port group 52 is also disconnected within a single continuous time zone. Is done. In this way, the links are disconnected at approximately the same timing for each group of communication terminals that frequently communicate with each other.

  In the case of a communication start command, the communication control unit 15 sets the port group table No. The transfer processing operations of the transfer unit 12 are sequentially started in the order of the numbers (that is, the order of arrangement of the communication port numbers), and the links 40 are sequentially established. In the case of the port group table shown in FIG. 4, first, a link for each communication terminal belonging to the port group 51 is established, and then a link for each communication terminal belonging to the port group 52 is established. Accordingly, each communication terminal belonging to the port group 51 is established within a single continuous time zone, and each communication terminal belonging to the port group 52 is established within a single continuous different time zone. Is done. In this way, a link is established at almost the same timing for each group of communication terminals that frequently communicate with each other.

  In the case of a communication port addition command, the communication control unit 15 associates the port number indicated by the command with the port group and adds it to the port group table. In the communication port addition command, for example, 51 is designated as the port group and 11-1 is designated as the port number. In this case, the port group 51 is associated with the port number 11-1 in the port group table. A plurality of port numbers may be specified for one port group at a time.

  In the case of a communication port deletion command, the communication control unit 15 deletes the port number indicated by the command from the port group table. In the communication port deletion command, for example, 11-1 is designated as the port number. In this case, the port number 11-1 and the corresponding port group 51 are deleted from the port group table. A plurality of port numbers may be specified at one time, and a port group may be specified together with the port numbers.

  Further, the communication control unit 15 may change the relationship between the port group and the port number according to the current time. For example, a communication terminal connected to the port number 11-x (x is an arbitrary integer) always communicates with a communication terminal belonging to the port group 51 between 1 pm and 2 pm, and 2 pm If it is known that the communication terminal 15 always communicates with the communication terminals belonging to the port group 52 between 3:00 and 3:00 pm, the communication control unit 15 associates the port number 11-x at the time of 2:00 pm The port group to be used may be changed from the port group 51 to the port group 52. When performing such processing, the communication control unit 15 holds, for example, a table in which port numbers, change times, and change destination port groups are associated with each other, and when the current time matches the change time, the port group and port Change the association with the number. Further, the communication control unit 15 may change the association between the port group and the port number in accordance with any one of the current date, day of the week, and public holiday.

  These functions included in the signal transfer apparatus 10-1 can be configured by hardware resources such as a microprocessor and a memory and software. The signal transfer device 10-2 has the same configuration as the signal transfer device 10-1.

  The communication terminal 20-1 has a function of establishing a link 40 with each of the signal transfer apparatuses 10-1 and 10-2 and transmitting / receiving signals. When the link 40 with the signal transfer device 10-1 and the link 40 with the signal transfer device 10-1 are both established, the communication terminal 20-1 sets the priority set in advance. The higher link 40 is used for communication.

  In addition, when the communication terminal 20-1 detects disconnection (link disconnection) of the link 40 currently used for communication, the communication terminal 20-1 has a function of switching to another link 40 with which the link has been established and performing communication. For example, when the signal transfer device 10-1 currently communicating is in a communication stop state and the communication terminal 20-1 detects the link disconnection, the link 40 established with the signal transfer device 10-1 is connected. Switch to communicate. When, for example, Linux is used as the operating system (OS), the path switching process by the communication terminal 20-1 can be executed using the bonding interface function.

  Each of the communication terminals 20-2 to 20-m and the communication terminals 30-1 to 30-n has the same function as the communication terminal 20-1.

  FIG. 5 is a sequence diagram showing the operation of each device in the link disconnection process. In FIG. 5, only the signal transfer apparatuses 10-1 and 10-2 and the communication terminals 20-1, 20-2, and 30-1 are illustrated for convenience of explanation. Hereinafter, the operation of each device in the link disconnection process will be described with reference to FIG.

  Each of the communication terminals 20-1, 20-2, and 30-1 has already established a link 40 with each of the signal transfer apparatuses 10-1 and 10-2. The communication terminal 20-1 and the communication terminal 20-2 communicate with each other using the link 40 established with the signal transfer apparatus 10-1 according to a preset priority (step S10). When the transfer unit 12 of the signal transfer device 10-1 receives a signal from one of the communication terminals 20-1, 20-2, and 30-1, the transfer unit 12 performs a process of transferring the signal to its destination. . As shown in FIG. 1, the communication terminals 20-1 and 20-2 belong to the same port group 51, and the communication terminal 30-1 belongs to a different port group 52.

  Here, for example, when the administrator of the signal transfer apparatus 10-1 wants to turn off the power of the signal transfer apparatus 10-1 for maintenance of the signal transfer apparatus 10-1, etc., for example, a communication network (see FIG. A communication stop command (or device stop command) is transmitted to the signal transfer device 10-1 via the signal transfer device 10-1.

  The command receiving unit 14 of the signal transfer apparatus 10-1 receives the communication stop command via a communication network (not shown) (step S11).

  In response to the communication stop command received by the command receiving unit 14, the communication control unit 15 of the signal transfer device 10-1 The links 40 are sequentially cut in the order of the numbers (step S12).

  In the case of the port group table shown in FIG. 4, the communication control unit 15 first stops communication for the port number 11-1 in the transfer unit 12, and communicates with the communication terminal 20-1 corresponding to the port number 11-1. The link between them is disconnected (step S13). Next, the communication control unit 15 stops the communication for the port number 11-6 in the transfer unit 12, and disconnects the link with the communication terminal 20-2 corresponding to the port number 11-6 (step S14). . Hereinafter, the communication control unit 15 is No. The same processing is performed in the order of the numbers.

  The communication terminal 20-1 detects a link break with the signal transfer apparatus 10-1, and starts a process of switching the communication path to the signal transfer apparatus 10-2 side (step S13). The communication terminal 20-2 also detects a link break with the signal transfer apparatus 10-1, and starts a process of switching the communication path to the signal transfer apparatus 10-2 side (step S14).

  At the time when the switching process in the communication terminal 20-1 is completed (step S15), the switching process in the communication terminal 20-2 is not completed, and the communication terminal 20-1 and the communication terminal 20-2 cannot communicate with each other. It is. At the time when the switching process in the communication terminal 20-2 is completed (step S16), since the switching process in the communication terminal 20-1 is also completed, the communication terminal 20-1 and the communication terminal 20-2 are connected to the signal transfer device 10-. 2 can start mutual communication (step S17).

  The communication control unit 15 of the signal transfer device 10-1 continues the link disconnection process (step S12), stops communication for the port number 11-4 in the transfer unit 12, and corresponds to the port number 11-4. The link with the communication terminal 30-1 is also disconnected (step S18). The communication terminal 30-1 detects a link break with the signal transfer apparatus 10-1, and starts a process of switching the communication path to the signal transfer apparatus 10-2 side (step S18).

  With this processing, first, the links for the communication terminals belonging to the port group 51 are sequentially disconnected. Next, the links for the communication terminals belonging to the port group 52 are sequentially disconnected. In this way, the communication control unit 15 executes the link disconnection process for each port group within a single continuous time zone. This minimizes the link disconnection detection interval of each of the communication terminals 20-1 and 20-2 belonging to the same port group 51, so that these two communication terminals that should frequently communicate with each other can quickly communicate with each other after the path is switched. Can start. Thereby, the communication loss at the time of the communication path switching by the communication terminal which detected link disconnection can be reduced.

  FIG. 6 is a sequence diagram showing the operation of each device in the link establishment process. In FIG. 6, only the signal transfer apparatuses 10-1 and 10-2 and the communication terminals 20-1, 20-2, and 30-1 are illustrated for convenience of explanation. Hereinafter, the operation of each device in the link establishment process will be described with reference to FIG.

  Each of the communication terminals 20-1, 20-2, and 30-1 has not yet established a link 40 with each of the signal transfer apparatuses 10-1 and 10-2. As shown in FIG. 1, the communication terminals 20-1 and 20-2 belong to the same port group 51, and the communication terminal 30-1 belongs to a different port group 52.

  Here, for example, when the administrator of the signal transfer device 10-1 wants to turn on the signal transfer device 10-1 after the maintenance of the signal transfer device 10-1 is completed, for example, a communication network (not shown) such as the Internet. ) To transmit a communication start command (or device activation command) to the signal transfer device 10-1.

  The command receiving unit 14 of the signal transfer device 10-1 receives the communication start command via a communication network (not shown) (step S21).

  The communication control unit 15 of the signal transfer device 10-1 responds to the communication start command received by the command receiving unit 14 in accordance with No. of the port group table. The communication for establishing the link 40 is sequentially started in the order of the numbers (step S22).

  In the case of the port group table shown in FIG. 4, the communication control unit 15 first communicates with the communication terminal 20-1 to establish a link with the communication terminal 20-1 corresponding to the port number 11-1. A start signal transmission instruction is given to the transfer unit 12. The transfer unit 12 transmits a communication start signal to the communication terminal 20-1 according to the instruction (step S23). Next, the communication control unit 15 instructs the transfer unit 12 to transmit a communication start signal to the communication terminal 20-2 in order to establish a link with the communication terminal 20-2 corresponding to the port number 11-6. To give. The transfer unit 12 transmits a communication start signal to the communication terminal 20-2 according to the instruction (step S24). Hereinafter, the communication control unit 15 is No. The same processing is performed in the order of the numbers.

  The communication terminal 20-1 detects a communication start signal from the signal transfer apparatus 10-1, and starts a process of establishing a link with the signal transfer apparatus 10-1 (step S23). The communication terminal 20-2 also detects a communication start signal from the signal transfer device 10-1 and starts a process of establishing a link with the signal transfer device 10-1 (step S24).

  At the time of completion of the link establishment process in the communication terminal 20-1 (step S25), the link establishment process in the communication terminal 20-2 is not completed, and the communication terminal 20-1 and the communication terminal 20-2 communicate with each other. It is not possible. At the time of completion of the link establishment process in the communication terminal 20-2 (step S26), since the link establishment process in the communication terminal 20-1 is also completed, the communication terminal 20-1 and the communication terminal 20-2 are signal transfer devices. Mutual communication can be started via 10-2 (step S27).

  The communication control unit 15 of the signal transfer device 10-1 continues the link establishment process (step S22), and the transfer unit 12 transmits a communication start signal to the communication terminal 30-1 corresponding to the port number 11-4. (Step S28). The communication terminal 30-1 also detects a communication start signal from the signal transfer device 10-1 and starts processing for establishing a link with the signal transfer device 10-1 (step S28).

  By such processing, first, links for each communication terminal belonging to the port group 51 are sequentially established. Next, a link for each communication terminal belonging to the port group 52 is sequentially established. In this way, the communication control unit 15 executes the link establishment process for each port group within a single continuous time zone. Thereby, since the link establishment of each of the communication terminals 20-1 and 20-2 belonging to the same port group 51 can be realized at substantially the same timing, these two communication terminals that should frequently communicate with each other perform mutual communication after the link establishment. Can start early.

  As described above, according to the signal transfer apparatus 10-1 according to the present embodiment, a set of communication terminals (for example, communication terminals 20-1 to 20-m) that should frequently communicate with each other are assigned to the same port group (for example, 51). Port groups 51 and 52 are configured to belong. Then, the signal transfer apparatus 10-1 stops communication at the communication ports corresponding to the communication terminals belonging to the same port group almost simultaneously according to the communication stop command (device stop command) (communication for each communication port). Shorten the execution interval of stop processing). With this process, communication terminals belonging to the same port group can switch communication paths at substantially the same timing. Since each communication terminal that should frequently communicate with each other can switch the communication path at substantially the same timing, it is possible to minimize the communication impossible time between the communication terminals due to a difference in switching timing. Thereby, the communication loss at the time of the communication path switching by the communication terminal which detected link disconnection can be reduced. In other words, in view of the increase in communication loss depending on the product of the mutual communication disabled time and the mutual communication frequency, the communication disabled time between communication terminals having a high mutual communication frequency has been shortened, thereby reducing the communication quality. can do.

  In addition, the signal transfer apparatus 10-1 according to the present embodiment starts communication of communication ports corresponding to communication terminals belonging to the same port group almost simultaneously (communication port) in response to a communication start command (device activation command). Shorten the execution interval of the communication start process for each). With this processing, communication terminals belonging to the same port group can start communication at substantially the same timing. Since each communication terminal that should frequently communicate with each other can start communication at substantially the same timing, there is also an effect that the communication start time between the communication terminals due to a difference in link establishment timing can be advanced as much as possible.

10-1, 10-2 Signal transfer devices 11-1 to 11-p Communication port 12 Transfer unit 13 Table storage unit (storage unit)
14 Command receiving unit 15 Communication control unit 20-1 to 20-m, 30-1 to 30-n Communication terminal 40 Link 51, 52 Port group

Claims (5)

A plurality of communication ports, a transfer unit that transfers a signal arriving via one of the communication ports to another one of the communication ports, and a transfer processing operation of the transfer unit in response to a stop command. A communication control unit that stops for each port and starts a transfer processing operation of the transfer unit for each communication port in response to a start command,
A storage unit that stores the port numbers of the communication ports in groups of at least two port groups;
The signal transfer device, wherein the communication control unit stops or starts a transfer processing operation by the transfer unit for each port group based on the port number in response to the stop command or the start command.   The signal transfer apparatus according to claim 1, wherein the communication control unit starts and stops the transfer processing operation in the order of arrangement of the port group numbers in the port group.   The signal transfer apparatus according to claim 1, further comprising changing means for changing a relationship between the port group and the port number.   4. The signal transfer apparatus according to claim 3, wherein the changing unit changes a relationship between the port group and the port number according to an external command.   4. The signal transfer apparatus according to claim 3, wherein the changing unit changes a relationship between the port group and the port number according to any one of a current date, a day of the week, a holiday, and a time.

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