JP2014236457A - Communication system, subscriber side device, and connection state monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably monitor a connection state of a subscriber side device and a terminal device.SOLUTION: The communication system includes: an ONU 13 connected to a station side device; a HUB 14 connected to the ONU 13; and terminal devices such as a VoIP-TA16 and a PC 15 connected under the HUB 14. The ONU 13 includes: a PING transmission part 28 that periodically transmits a PING to the terminal devices; and a connection state detection part 30 that detects link-down of the terminal device when there is no PING response from the terminal device.

Description

  The present invention relates to a connection state monitoring method for a terminal device connected to a subordinate of a subscriber side device via a relay device in a communication system including a station side device and a subscriber side device.

  2. Description of the Related Art Conventionally, a PON (Passive Optical Network) system has been known as a subscriber optical fiber network system for subscriber homes such as ordinary homes. In this PON system, one optical fiber connected to a station side device (OLT (Optical Line Terminal)) installed in a telecommunications carrier station is branched by an optical splitter, and a plurality of subscriber side devices (ONU (ONU ( Optical Network Unit)). The PON system has a low-cost optical communication network because a single optical fiber is shared by a plurality of subscriber-side devices, compared to a single star system in which station-side devices and subscriber-side devices are connected one-to-one. Can be built.

  In the PON system, a technique for remotely monitoring a connection state between a subscriber side device and a terminal (for example, VoIP-TA, personal computer, etc.) connected to the subscriber side device via a network is known. Yes. For example, in Patent Literature 1, when a terminal device is connected to a connection port of a subscriber side device, a link up is notified to the station side device, and when a terminal is removed from the connection port, a link down is notified to the station side device. A person side device is disclosed.

JP 2011-259063 A

  However, in the detection of a physical connection state (link up / link down) as disclosed in Patent Document 1, a relay device such as a HUB is provided between a subscriber side device and a terminal device under its control. In addition, the subscriber side device may not be able to monitor the connection state between itself and the terminal device. This is because the subscriber side device does not detect a physical link down unless the connection between itself and the relay device is broken.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which can monitor suitably the connection state of a subscriber side apparatus and a terminal device.

  In order to solve the above problems, a communication system according to an aspect of the present invention is connected to a subscriber-side device connected to a station-side device, a relay device connected to the subscriber-side device, and a relay device. A terminal device. The subscriber side device includes a PING transmission unit that periodically transmits a PING to the terminal device, and a connection state detection unit that detects a link down of the terminal device when there is no PING response from the terminal device.

  The subscriber side device may further include a MAC address learning table for registering the MAC address of the terminal device under the relay device. The PING transmission unit may transmit the PING to the terminal device based on the MAC address registered in the MAC address learning table.

  The connection state detection unit may detect a link down of the terminal device when the PING response from the terminal device cannot be received for a predetermined period.

  Another aspect of the present invention is a subscriber-side device. This device is a subscriber side device connected to a terminal device via a relay device, and when there is no PING response from the terminal device and a PING transmission unit that periodically transmits a PING to the terminal device, A connection state detection unit for detecting a link down of the terminal device.

  Yet another embodiment of the present invention is a connection state monitoring method. This method is a connection state monitoring method between a subscriber side device and a terminal device connected via a relay device, a step of periodically transmitting a PING from the subscriber side device to the terminal device, and a terminal device. And detecting a link down of the terminal device when there is no PING response.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between an apparatus, a method, a system, a program, a recording medium storing the program, and the like are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can monitor suitably the connection state of a subscriber side apparatus and a terminal device can be provided.

It is a figure which shows the communication system which concerns on embodiment of this invention. It is a functional block diagram for demonstrating the connection state monitoring function in the communication system which concerns on this embodiment. It is a flowchart which shows the connection state monitoring process of ONU which concerns on this embodiment.

  FIG. 1 is a diagram showing a communication system 10 according to an embodiment of the present invention. Each block shown in the present specification can be realized in hardware by an element such as a CPU of a computer or a mechanical device, and is realized in software by a computer program or the like. Depicts functional blocks realized by. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The communication system 10 according to the present embodiment is a communication system that employs a PON method. As shown in FIG. 1, the communication system 10 includes a plurality of station side devices (OLT) 11 connected to a main signal network 18. One optical fiber connected to each OLT 11 is branched into a plurality of optical fibers by an optical splitter 12, and a subscriber unit (ONU) 13 is connected to the end of each optical fiber.

  A HUB 14 is connected to the ONU 13 installed in the subscriber's home. A personal computer (PC) 15 and a VoIP-TA 16 are connected under the HUB 14. An IP telephone 17 is connected to the VoIP-TA 16. In addition, although HUB14 was illustrated as an example of the relay apparatus connected to ONU13 here, a relay apparatus is not limited to HUB14. Further, here, the PC 15 and the VoIP-TA 16 are illustrated as examples of the terminal device connected to the HUB 14, but the terminal device is particularly suitable if it can respond to a PING (Packet Internet Groper) from the ONU 13, as will be described later. For example, a set top box (STB) or a LAN-compatible hard disk device may be connected to the HUB 14.

  The communication system 10 according to the present embodiment further includes a monitoring device 20 for remotely monitoring each device in the communication system 10. In the present embodiment, the monitoring device 20 is connected to each OLT 11 via a monitoring control network 19 different from the main signal network 18. In the communication system 10, signal transmission from the monitoring device 20 to each OLT 11 is performed in an out-band manner via the monitoring control network 19, and signal transmission from the OLT 11 to the ONU 13, the PC 15 under the ONU 13, and the VoIP-TA 16 is mainly performed. It is performed in an in-band method using a signal line.

  In the communication system 10 according to the present embodiment, the monitoring device 20 has a function of monitoring the connection state between the ONU 13 and terminal devices (PC15, VoIP-TA16, etc.) under the ONU13. In the following, this connection state monitoring function will be described.

  FIG. 2 is a functional block diagram for explaining the connection state monitoring function in the communication system according to the present embodiment.

  As shown in FIG. 2, the ONU 13 includes an optical transmission / reception unit 24, a transfer processing unit 25, a terminal-side interface unit 26, a MAC address learning table 27, a PING transmission unit 28, a PING reception unit 29, and a connection state. A detection unit 30 and a connection state notification unit 31 are provided.

  The optical transmission / reception unit 24 transmits / receives an optical signal to / from the OLT 11. That is, the optical transmission / reception unit 24 converts the optical signal from the OLT 11 into an electrical signal and sends it to the transfer processing unit 25, and converts the electrical signal from the transfer processing unit 25 into an optical signal and transmits it to the OLT 11.

  The transfer processing unit 25 performs transfer processing of signals received from the OLT 11 and the terminal devices under its control. When performing the transfer process, the transfer processing unit 25 refers to the MAC address of the subordinate terminal device registered in the MAC address learning table 27.

  The terminal-side interface unit 26 is an interface unit for performing communication with the terminal device, and includes a connection port 26a. The connection port 26 a of the terminal side interface unit 26 is connected to the HUB 14.

  The MAC address learning table 27 manages the MAC addresses of the terminal devices connected under the HUB 14, that is, the PC 15 and the VoIP-TA 16. When the terminal device is connected to the HUB 14, the MAC address of the terminal device is registered in the MAC address learning table 27 (dynamic learning). Alternatively, a network maintenance person registers the MAC address of the terminal device in the MAC address learning table 27 by a command (static learning).

  The PING transmission unit 28 periodically transmits an Internet Control Message Protocol (ICMP) PING to terminal devices connected under the HUB 14. The PING transmission interval can be arbitrarily specified, and the number of transmission frames can also be arbitrarily specified. Transmission of PING by the PING transmission unit 28 is performed based on the MAC address registered in the MAC address learning table 27.

  A maintenance person of the communication system 10 selects whether or not to monitor the status of the terminal devices under each ONU 13. When monitoring the status, the PING transmitting unit 28 is designated via the monitoring device 20 to which MAC address registered in the MAC address learning table 27 is to transmit the PING. By specifying the MAC address, the PING transmission unit 28 starts transmitting PING to the target MAC address. For the designation of the MAC address, all the MAC addresses registered in the MAC address learning table 27 or a specific MAC address can be selected. Further, the PING transmission unit 28 may transmit PING to an arbitrarily set MAC address without using the MAC address learning table 27.

  The PING receiving unit 29 receives a PING response from the terminal device connected to the HUB 14. The PING response that arrives at the connection port 26 a of the ONU 13 is sent from the terminal-side interface unit 26 to the transfer processing unit 25, and transferred from the transfer processing unit 25 to the PING receiving unit 29.

  The PING receiving unit 29 sends information indicating whether or not a PING response has been received from the terminal device that has transmitted the PING to the connection state detecting unit 30. The connection state detection unit 30 detects the connection state of the terminal device to be monitored based on the PING response information. That is, if there is a PING response from the terminal device that has transmitted PING, it can be determined that the terminal device is in a link-up state (communication enabled state) with ONU 13. On the other hand, if there is no PING response from the terminal device that transmitted the PING, it can be determined that the terminal device is in a link down state (communication impossible state) with the ONU 13.

  Here, the connection state detection unit 30 does not immediately determine that the link is down when there is no PING response from the terminal device that has transmitted the PING, but instead determines that the PING response from the terminal device is a predetermined period ("PING no response period"). It is desirable to determine that the terminal device is link down when reception is impossible. Depending on the PING transmission interval and the number of MAC addresses transmitting the PING, the PING transmission cycle for one terminal device changes. Further, the MAC address learning table 27 deletes the MAC address from the table when a certain time (Aging Time) signal is not received from a certain MAC address, but this Aging Time can be arbitrarily changed. Therefore, it is preferable that the PING non-response period used for the link down determination can be arbitrarily set.

  The connection state notification unit 31 notifies the OLT 11 of the connection state information between the ONU 13 and the terminal device detected by the connection state detection unit 30 together with the MAC address of the terminal device. The connection status information transmitted from the connection status notification unit 31 is sent to the OLT 11 via the transfer processing unit 25 and the optical transmission / reception unit 24. The OLT 11 notifies the monitoring device 20 of connection state information via the monitoring control network 19 (see FIG. 1). The monitoring device 20 manages the connection state for each MAC address.

  As shown in FIG. 2, the HUB 14 includes a first connection port 14a, a second connection port 14b, and a third connection port 14c. The HUB 14 may be a repeater hub that functions as a repeater or a switching hub having a switch function.

  The PC 15 includes an ONU side interface unit 33 having a connection port 33 a and a PING response unit 34 that responds to a PING from the ONU 13. The connection port 33a is connected to the second connection port 14b of the HUB 14. The VoIP-TA 16 includes an ONU-side interface unit 37 having a connection port 37a and a PING response unit 38 that responds to a PING from the ONU 13. The connection port 37a is connected to the third connection port 14c of the HUB 14.

  FIG. 3 is a flowchart showing connection state monitoring processing of the ONU 13 according to this embodiment. The process shown in the flowchart of FIG. 3 is repeatedly performed at predetermined time intervals.

  First, the PING transmitter 28 of the ONU 13 refers to the MAC address learning table 27 and transmits a PING to the terminal device to be monitored (S10).

  Next, the PING receiving unit 29 determines whether or not a PING response has been received from the terminal device (S12). When the PING reception unit 29 receives a PING response (Y in S12), the connection state detection unit 30 determines that the terminal device and the ONU are in a link-up state (S14), and the link-up information is transmitted to the terminal device. The OLT is notified together with the MAC address (S16).

  On the other hand, when the PING receiving unit 29 does not receive a PING response (N in S12), the connection state detecting unit 30 determines that the terminal device and the ONU are in a link down state (S18), and the link down information is transmitted to the terminal. The OLT is notified together with the MAC address of the device (S16).

  In the case of a method for monitoring whether a terminal device is physically connected to the ONU 13 (referred to as a connection state monitoring method using a physical line), the connection between the ONU 13 and the terminal device needs to be 1: 1 connection. As shown in FIG. 2, when a HUB 14 is inserted between the ONU 13 and the terminal device, and the ONU 13 and the terminal device are connected by 1: N (N is an integer of 2 or more), connection state monitoring using a physical line is performed. In the method, the ONU 13 can detect a link down between itself and the HUB 14, but cannot detect a link down between the HUB 14 and the terminal device.

  On the other hand, in the communication system 10 according to the present embodiment, the connection state between the ONU 13 and a terminal device under its control is monitored using PING. This monitoring method can be called a connection state monitoring method using a logical line. By using such a connection state monitoring method using a logical line, even when the HUB 14 is inserted between the ONU 13 and the terminal device, the ONU 13 can detect the link down of the subordinate terminal device. it can.

  Conventionally, Ethernet (registered trademark) OAM (Operations, Administration, Maintenance) has been generally used to monitor the state of a terminal device using a logical line. However, PON devices, ADSL devices, VDSL devices, and the like often do not have an Ethernet OAM function. With the state monitoring method using PING as in the present embodiment, the connection state can be monitored even for devices that do not have the Ethernet OAM function.

  Further, in the connection state monitoring method using a physical line, the link down does not occur if the connection port of the ONU 13 and the connection port of the terminal device are connected. Therefore, for example, when the connection between the CPU in the ONU 13 (which realizes functional blocks such as the transfer processing unit 25 and the PING transmission unit 28) and the connection port 26a is disconnected, or connected to the CPU in the PC 15 which is a terminal device. If the connection with the port 33a is broken, link down cannot be detected.

  On the other hand, in the communication system 10 according to the present embodiment, if the connection between the connection port and the CPU is disconnected, there is no PING response even if the PING is transmitted, so that an abnormality due to the disconnection in the apparatus can be detected.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  For example, in the above-described embodiment, the monitoring device 20 and the OLT 11 are connected out-of-band via the monitoring control network 19, but may be connected in-band via the main signal network 18.

  In the above-described embodiment, PING is used to monitor the connection state between the ONU 13 and the terminal device. However, PING may be used to monitor the connection state between the OLT 11 and its upper switch device. Normally, the upper switching device of the OLT 11 has the Ethernet OAM function, but the OLT 11 may not be provided. Therefore, the connection state between the OLT 11 and the upper switch device can be monitored by transmitting a PING from the OLT 11 to the upper switch device and determining the presence or absence of a PING response.

  DESCRIPTION OF SYMBOLS 10 Communication system, 11 OLT, 13 ONU, 14 HUB, 15 PC, 16 VoIP-TA, 18 Main signal network, 19 Monitoring control network, 20 Monitoring apparatus, 24 Optical transmission / reception part, 25 Transfer processing part, 26 Terminal side interface part 27 MAC address learning table, 28 PING transmission unit, 29 PING reception unit, 30 connection state detection unit, 31 connection state notification unit, 33, 37 ONU side interface unit, 34, 38 PING response unit.

Claims (5)

A subscriber side device connected to the station side device;
A relay device connected to the subscriber side device;
A terminal device connected under the relay device;
A communication system comprising:
The subscriber side device is:
A PING transmitter that periodically transmits a PING to the terminal device;
When there is no PING response from the terminal device, a connection state detection unit that detects a link down of the terminal device;
A communication system comprising: The subscriber side device further includes a MAC address learning table for registering a MAC address of a terminal device under the relay device,
The communication system according to claim 1, wherein the PING transmission unit transmits a PING to the terminal device based on a MAC address registered in the MAC address learning table.   The communication system according to claim 1, wherein the connection state detection unit detects a link down of the terminal device when the PING response from the terminal device cannot be received for a predetermined period. A subscriber side device connected to a terminal device via a relay device,
A PING transmitter that periodically transmits a PING to the terminal device;
When there is no PING response from the terminal device, a connection state detection unit that detects a link down of the terminal device;
A subscriber-side device comprising: A method for monitoring a connection state between a subscriber-side device and a terminal device connected via a relay device,
Periodically sending a PING from the subscriber side device to the terminal device;
Detecting a link down of the terminal device when there is no PING response from the terminal device;
A connection state monitoring method comprising:

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