JP2022002374A - Communication device, home side device, and pon system - Google Patents

Abstract

The present invention provides a communication device, a home device, and a PON system in which a communication device to which a home device can be connected appropriately acts as a control communication link between a station device and a home device. [Solution] A line concentrator 3 is a communication device that communicates with a home device ONU that constitutes a PON system together with a central office device OLT, and has one or more physical ports P1 and P2 to which two home devices can be connected. , a management control unit 34 that manages connected home-side devices, and relay processing units 31, 32, and 33 that relay communication frames transmitted and received by the home-side devices and the management control unit. The management control unit 34 allows the station-side device to communicate with the station-side device on the condition that the first communication link, which is a control communication link that the communication device attempts to establish with the home-side device as the management target, has been established between the home-side device and the communication device. A second communication link, which is a control communication link that is attempted to be established with the home device as the management target, is established. [Selection diagram] Figure 2

Description

The present invention relates to a communication device, a home-side device, and a PON system.

In Patent Document 1, an OLT (Optical Line Terminal), a plurality of pluggable ONUs (Optical Network Units) conforming to the MSA (Multi Source Agreement) standard connected by an OLT and a PON line, and a pluggable ONU can be inserted. A PON (Passive Optical Network) system including a concentrator having a plurality of physical ports is described.

Japanese Unexamined Patent Publication No. 2010-252192

In the PON system of Patent Document 1, if some of the functions (for example, OAM) of the hardware components included in the pluggable ONU are transferred to the concentrator, the circuit configuration of the hardware components can be reduced to a small scale, and the pluggable ONU can be used. It can be made smaller and more versatile.
However, Patent Document 1 does not envision a procedure for control communication for the concentrator to appropriately substitute for the OAM link between the OLT / ONU.

In view of the conventional problems, an object of the present disclosure is to enable a communication device to which a home-side device can be connected to appropriately substitute a control communication link between a station-side device and a home-side device.

The device according to one aspect of the present disclosure is a communication device that communicates with a home-side device constituting a PON system together with a station-side device, and is already connected to one or a plurality of physical ports to which the home-side device can be connected. A management control unit that manages the home-side device and a relay processing unit that relays communication frames transmitted and received by the home-side device and the management control unit are provided, and the management control unit includes the home-side device and the following. On condition that the first communication link is established, the following second communication link is established with the station-side device.
1st communication link: Control communication link in which the communication device tries to establish the home side device as a management target 2nd communication link: Control communication link in which the station side device tries to establish the home side device as a management target

The device according to another aspect of the present disclosure is a home-side device that constitutes a PON system together with a station-side device, and is connected to an optical transceiver, a PON processing unit connected to the optical transceiver, and the PON processing unit. A PHY processing unit and a terminal module connected to the PHY processing unit that can be directly or indirectly connected to a physical port of the communication device are provided, and the PON processing unit is the communication device. And the above-mentioned first communication link is established, the above-mentioned second communication link is not established with the station-side device, and the control frame used for establishing the second communication link is relayed.

The system according to one aspect of the present disclosure includes a station-side device, a plurality of home-side devices connected to the station-side device by a PON line, and a communication device to which all or part of the plurality of home-side devices are connected. A PON system including, and the home-side device connected to the communication device does not establish the following second communication link with the station-side device, and is used for establishing the second communication link. The control frame is relayed, and the communication device establishes the second communication link with the station-side device on condition that the first communication link is established with the home-side device connected to the own device. ..

According to the present disclosure, a communication device to which a home-side device can be connected can appropriately substitute for a control communication link between a station-side device and a home-side device.

FIG. 1 is a schematic diagram showing an example of the overall configuration of an optical communication system. FIG. 2 is a block diagram showing an example of the internal configuration of the OLT, the pluggable ONU, and the concentrator. FIG. 3A is a sequence diagram showing an example of the monitoring process of the pluggable ONU. FIG. 3B is a sequence diagram showing another example of the monitoring process of the pluggable ONU. FIG. 4 is a sequence diagram showing an example of a link-up procedure for PON communication. FIG. 5 is a block diagram showing the overall configuration of the optical communication system according to the first modification. FIG. 6 is a block diagram showing the overall configuration of the optical communication system according to the second modification.

<Outline of Embodiment of the present invention>
Hereinafter, the outlines of the embodiments of the present invention will be described in a list. In addition, at least a part of the embodiments described below may be arbitrarily combined.

(1) The communication device of the present embodiment is a communication device that communicates with the home-side device constituting the PON system together with the station-side device, and has already been connected to one or a plurality of physical ports to which the home-side device can be connected. A management control unit that manages the home-side device and a relay processing unit that relays communication frames transmitted and received by the home-side device and the management control unit, and the management control unit includes the home-side device and the following. On condition that the first communication link of the above is established, the following second communication link is established with the station-side device.
1st communication link: Control communication link in which the communication device tries to establish the home side device as a management target 2nd communication link: Control communication link in which the station side device tries to establish the home side device as a management target

According to the communication device of the present embodiment, the management control unit establishes the above-mentioned second communication link with the station-side device on condition that the above-mentioned first communication link is established with the home-side device. A communication device to which the device can be connected can appropriately substitute for the control communication link (second communication link) between the station side device and the home side device.

(2) In the communication device of the present embodiment, it is preferable that the management control unit acquires the setting information of the home-side device by control communication with the station-side device opened by establishing the second communication link. ..
By doing so, the management control unit of the communication device can appropriately acquire the setting information of the home-side device transmitted by the station-side device for the home-side device.

(3) In the communication device of the present embodiment, the management control unit obtains the setting information of the home-side device by the control communication with the home-side device opened by establishing the first communication link. It is preferable to send to the device.
By doing so, the management control unit of the communication device can appropriately provide the setting information of the home-side device acquired from the station-side device to the home-side device.

(4) In the communication device of the present embodiment, the management control unit acquires the address information of the connected home-side device by the control communication at the time of establishing the first communication link, and uses the acquired address information. Based on this, it is preferable to determine the transmission destination of the acquired setting information of the home-side device.
By doing so, when the setting information of a plurality of home-side devices is acquired from the station-side device, the communication device can provide the setting information of the home-side device to an appropriate destination.

(5) The home-side device of the present embodiment is a home-side device that constitutes a PON system together with a station-side device, and is connected to an optical transceiver, a PON processing unit connected to the optical transceiver, and the PON processing unit. The PHY processing unit is provided with a terminal module connected to the PHY processing unit and can be directly or indirectly connected to the physical port of the communication device, and the PON processing unit is the PON processing unit. The above-mentioned first communication link is established with the communication device, the above-mentioned second communication link is not established with the station-side device, and the control frame used for establishing the second communication link is relayed.

According to the home-side device of the present embodiment, the PON processing unit establishes the above-mentioned first communication link with the communication device, does not establish the above-mentioned second communication link with the station-side device, and does not establish the above-mentioned second communication link. Since the control frame used for establishment is relayed, the communication device to which the home-side device can be connected can appropriately substitute the control communication link (second communication link) between the station-side device and the home-side device.

(6) The PON system of the present embodiment is a system related to a combination including the above-mentioned communication devices (1) to (4) and the above-mentioned home-side device (5).
Therefore, the PON system of the present embodiment has the same effect as the communication device of (1) to (4) described above and the home-side device of (5) described above.

<Details of the Embodiment of the present invention>
Hereinafter, the details of the embodiment of the present invention will be described with reference to the drawings. In addition, at least a part of the embodiments described below may be arbitrarily combined.

[Overall configuration of optical communication system]
FIG. 1 is a schematic diagram showing an example of the overall configuration of an optical communication system.
As shown in FIG. 1, the optical communication system of the present embodiment includes a PON system including a station-side device 1, a home-side device 2, a concentrator device 3, and the like.
The station-side device 1 is an optical network unit (OLT) connected to the upper side of the PON line 4. The home-side device 2 is an optical network unit (ONU) located on the lower side of the PON line 4. Hereinafter, the station-side device 1 will be referred to as “OLT1”, and the home-side device 2 will be referred to as “ONU2”.

The PON of the present embodiment is, for example, a PON according to an IEEE-based communication standard (for example, GE-PON or 10G-EPON).
The PON of the present embodiment may be a PON according to an ITU-T communication standard (for example, G-PON, XG-PON, XGS-PON, NG-PON2, etc.).

The OLT 1 is installed in, for example, a telecommunications carrier's station building. OLT1 is connected to the upper network. The ONU 2 and the concentrator 3 are installed in, for example, a building of a subscriber (user) of a communication service.
The ONU2 includes a relatively small "pluggable ONU2A" that conforms to the MSA (Multi-Source Agreement) standard and a relatively large "stationary ONU2B" that does not comply with the MSA standard.

The MSA standard is, for example, "SFP" (Small Form-factor Pluggable), "SFP +" (Small Form-factor Pluggable Plus), or "XFP" (10 Gigabit Small Form-factor Pluggable).
In the following, "pluggable type ONU2A" may be abbreviated as "ONU2A", and "stationary type ONU2B" may be abbreviated as "ONU2B". Matters common to ONU2A and ONU2B will be described as "ONU2" using the common reference numeral "2".

The concentrator 3 includes, for example, a management switch including a plurality of physical ports. The physical port of the concentrator 3 is a slot-in type physical port Pi (i = 1, 2, ... m) to which a pluggable ONU2A can be connected, and a physical port Qj (j) to which a communication cable such as a LAN cable can be connected. = 1,2 ... n) is included.
The concentrator 3 has an Ethernet (“Ethernet” is a registered trademark) communication function conforming to 10/100/1000 BASE-T, a network function of the L2 / L3 layer, a QoS (Quality of Service) function, and a VLAN ( It has a Virtual LAN) function.

One or more pluggable ONU2A and one or more user terminals 5 are connected to the line concentrator 3. One or more user terminals 5 are connected to the stationary ONU2A. The user terminal 5 is an example of a "lower device" which is a communication device on the subscriber side.
The user terminal 5 is composed of a computer device capable of Ethernet communication such as a personal computer. The user terminal 5 may be connected to the concentrator 3 or ONU2B via a relay network (not shown).

The PON line 4 is composed of an optical line having a tree structure in which an optical fiber is branched by an optical splitter 6. The OLT 1 is connected to the trunk line fiber 7 of the PON line 4, and the ONU 2 is connected to the branch line fiber 8 of the PON line 4.
The optical splitter 6 passively branches or multiplexes an optical signal from an input optical signal without the need for power supply.

The downlink signal transmitted by the OLT 1 is branched at the optical splitter 6 and transmitted to each ONU 2 through the branch line fiber 8. The upstream optical signal transmitted by each ONU 2 is focused by the optical splitter 6 and transmitted to the OLT 1 through the trunk fiber 7.
Since the uplink signals transmitted by the ONU 2 are merged by the optical splitter 6, multiplexing is required so that the uplink signals having the same wavelength do not collide after the merge. Therefore, in PON, time division multiplexing is performed according to MPCP (Multi-Point Control Protocol).

Specifically, the ONU2 transmits a control frame (report) describing the data length (transmission request amount) in its own buffer to the OLT1.
Based on the report collected from the subordinate ONU2, the OLT1 calculates the transmission start time and the transmission time length in the upward direction instructed to each ONU2. The OLT 1 transmits a control frame (gate) including the calculation result to each ONU 2.

Each ONU2 transmits data corresponding to the transmission time length specified by the gate to the OLT1 at the transmission start time specified by the gate. At the same time, ONU2 transmits the next transmission request amount to OLT1 together with the report.
Further, the OLT 1 executes P2MP (Point To Multi Point) discovery, and when it detects the connection of the ONU2 to the PON line 4, it executes the registration process of the detected ONU2. At this time, LLID (Logical Link ID) is assigned to ONU2.

Since the PON system is Ethernet compliant, the OLT 1 has an OAM (Operations, Administration and Maintenance) function according to the Ethernet standard.
Therefore, the OLT 1 is a communication device to be managed, for example, a normal OAM frame defined in Clause 57 of IEEE802.3-2008 and an extended OAM frame that can be independently defined by a telecommunications carrier for the purpose of maintenance management. Send and receive to and from a certain ONU2.

In the optical communication system of FIG. 1, the stationary ONU2B may not be connected to the PON line 4, and only the pluggable ONU2A may be accommodated in the OLT1.
Further, the system configuration may include a plurality of concentrators 3, and the number of pluggable ONU2A connected to one concentrator 3 may be at least one.

[Internal configuration of OLT]
FIG. 2 is a block diagram showing an example of the internal configuration of the OLT 1, the pluggable ONU2A, and the concentrator 3.
As shown in FIG. 2, the OLT 1 includes an optical transceiver (TRx) 11, a PON processing unit 12, a switch unit 13, and a management control unit 14. The management control unit 14 is composed of a CPU (Central Processing Unit), a memory, and the like.

The optical transceiver 11 comprises an optical device including a subassembly (eg, Bidirectional Optical Sub-Assembly) that mutually converts an optical signal and an electrical signal. The optical transceiver 11 is optically connected to the PON line 4 and electrically connected to the PON processing unit 12.
The optical transceiver 11 converts an uplink signal input from the PON line 4 into an electric signal and inputs it to the PON processing unit 12, and converts the electric signal input from the PON processing unit 12 into a downlink optical signal to convert the PON line. Send to 4.

The PON processing unit 12 includes an integrated circuit (for example, a MAC chip for OLT) that executes predetermined communication processing or the like in accordance with the PON communication standard.
When the uplink frame input from the optical transceiver 11 is a report, the PON processing unit 12 calculates the transmission start time and transmission time length in the uplink direction of the ONU 2. The PON processing unit 12 generates a gate addressed to a predetermined LLID (ONU2) including the calculation result, and outputs the generated gate to the optical transceiver 11.

The PON processing unit 12 also executes P2MP discovery, registration processing of ONU2, transmission / reception of OAM frames for managing ONU2, and the like.
When the uplink frame input from the optical transceiver 11 is a user frame, the PON processing unit 12 outputs the user frame to the switch unit 13.
When the downlink frame input from the switch unit 13 is a user frame, the PON processing unit 12 outputs the user frame to the optical transceiver 11.

The switch unit 13 includes an integrated circuit such as an FPGA (Field Programmable Gate Array) that determines an output port according to the destination of the frame of the L2 layer input to itself.
When the downlink frame input from the upper network is a user frame, the switch unit 13 outputs the downlink frame to the PON processing unit 12.
When the uplink frame input from the PON processing unit 12 is a user frame, the switch unit 13 sends the user frame to the upper network.

The management control unit 14 is connected to the switch unit 13 and the PON processing unit 12. The management control unit 14 is also communicably connected to the management terminal 15 of the telecommunications carrier. The management terminal 15 may communicate with the management control unit 14 through the upper network.
The management control unit 14 can set the QoS (Quality of Service) parameter (for example, the maximum communication band) of the switch unit 13. The switch unit 13 adjusts the data communication amount of the user frame so as to have the set parameter value.

The management terminal 15 can transmit the setting information of the OLT 1 and the ONU 2 to the management control unit 14. When the management control unit 14 receives the setting information of the OLT 1, the management control unit 14 adjusts the parameters of each unit of the own device according to the received setting information.
When the management control unit 14 receives the setting information of the ONU 2, the management control unit 14 outputs the received setting information to the PON processing unit 12. The PON processing unit 12 generates a control frame (for example, an extended OAM frame) including the setting information of the ONU2 and outputs it to the optical transceiver 11.

The ONU2 setting information includes, for example, at least one of the following information 1 to 4.
Information 1: Setting parameters of the MAC chip of ONU2 Information 2: Authentication information (password, etc.) of the user terminal 5 that communicates with ONU2
Information 3: Encryption key used between OLT / ONU Information 4: Queue buffer size setting information included in ONU2

[Internal configuration of pluggable ONU]
As shown in FIG. 2, the pluggable ONU2A includes an optical transceiver (TRx) 21, a PON processing unit 22, a PHY (physical layer) processing unit 23, and a terminal module (terminal unit) 24. The terminal module 24 comprises a connector having a predetermined structure and a predetermined number of terminals conforming to a predetermined MSA standard.

The optical transceiver 21 comprises an optical device including a subassembly (eg, Bidirectional Optical Sub-Assembly) that mutually converts an optical signal and an electrical signal. The optical transceiver 21 is optically connected to the PON line 4 and electrically connected to the PON processing unit 22.
The optical transceiver 21 converts the downlink optical signal input from the PON line 4 into an electric signal and inputs it to the PON processing unit 22, and converts the electric signal input from the PON processing unit 22 into an uplink optical signal to convert the PON line. Send to 4.

The PON processing unit 22 includes an integrated circuit (for example, a MAC chip for ONU) that executes predetermined communication processing or the like in accordance with the PON communication standard.
The PON processing unit 22 generates a report describing the data length in its own buffer and outputs it to the optical transceiver 21. When the downlink frame input from the optical transceiver 21 is a gate, the PON processing unit 22 generates a user frame containing the data stored in the buffer and outputs the user frame to the optical transceiver 21 according to the instruction content written on the gate. do.

When the downlink frame input from the optical transceiver 21 is a user frame, the PON processing unit 22 outputs the user frame to the PHY processing unit 23.
When the uplink frame input from the PHY processing unit 23 is a user frame, the PON processing unit 22 temporarily stores the data included in the user frame in the buffer.

The PHY processing unit 23 includes an integrated circuit (for example, a PHY chip) that executes signal conversion, communication processing, and the like in the physical layer.
The PHY processing unit 23 converts the electric signal input from the concentrator 3 into the electric signal of the layer 2, and outputs the converted electric signal to the PON processing unit 22. The PHY processing unit 23 converts the downlink frame input from the PON processing unit 22 into an electric signal of layer 1, and sends the converted electric signal to the concentrator 3.

[Internal configuration of concentrator]
As shown in FIG. 2, the concentrator 3 includes a plurality of upper transmission / reception units 31, a switch unit 32, a plurality of lower transmission / reception units 33, and a management control unit 34. The management control unit 34 is composed of a CPU, a memory, and the like.
The upper transmission / reception unit 31 is connected to the physical ports P1 and P2, and the lower transmission / reception unit 33 is connected to the physical ports Q1 and Q2. In FIG. 2, the case where each of the transmission / reception units 31 and 33 is two is illustrated, but the number may be three or more.

The upper transmission / reception unit 31 includes an integrated circuit (for example, a PHY chip) that executes signal conversion, communication processing, and the like in the physical layer.
The upper transmission / reception unit 31 converts the electric signal input from the ONU 2A into the electric signal of the layer 2, and outputs the converted electric signal to the switch unit 32. The upper transmission / reception unit 31 converts the electric signal input from the switch unit 32 into a layer 1 electric signal, and sends the converted electric signal to ONU2A.

The lower transmission / reception unit 33 includes an integrated circuit (for example, a PHY chip) that executes signal conversion and communication processing in the Ethernet physical layer conforming to 10/100/1000 BASE-T or the like.
The lower transmission / reception unit 33 converts the electric signal input from the user terminal 5 into the electric signal of the layer 2, and outputs the converted electric signal to the switch unit 32. The lower transmission / reception unit 33 converts the electric signal input from the switch unit 32 into the electric signal of the layer 1, and sends the converted electric signal to the user terminal 5.

The switch unit 32 includes an integrated circuit such as an FPGA that determines an output port according to the destination of the frame of the L2 layer input to itself.
In the switch unit 32, the correspondence relationship between the upper transmission / reception unit 31 and the lower transmission / reception unit 33 is preset by the VLAN setting by the management control unit 34 or the like. A VLAN for management communication between the management control unit 34 and the ONU2A (hereinafter referred to as "management VLAN") is also set in advance in the switch unit 32. In the management VLAN, frame wrapping between different physical ports Pi is prohibited.

The switch unit 32 relays the input frame (Ethernet frame with a VLAN tag) according to the correspondence set by the management control unit 34.
Therefore, the upper transmission / reception unit 31, the switch unit 32, and the lower transmission / reception unit 33 function as a relay processing unit that relays the communication frames transmitted / received by the connected ONU2A, the connected user terminal 5, and the management control unit 34. do.

The management control unit 34 is connected to the switch unit 32. The management control unit 34 can also communicate with the management terminal 15 of the telecommunications carrier connected to the OLT 1.
Communication between the management terminal 15 and the management control unit 34 of the concentrator 3 is executed via the OLT 1, the PON line 4, and the ONU2A. The management terminal 15 may be directly connected to the management control unit 34 of the line concentrator 3.

[Virtualization of ONU functions]
In the present embodiment, a part of the functions of the hardware component (specifically, the PON processing unit 22) included in the ONU2A is transferred to the line concentrator 3. That is, the management control unit (CPU) 34 of the line concentrator 3 executes a part of the functions of the PON processing unit 22.
The more functions that can be transferred to the concentrator 3, the smaller the circuit configuration of the hardware components of the ONU2A can be, and the smaller and more versatile the ONU2A can be.

FIG. 2 illustrates a case where the function of the ONU2A that shifts to the management control unit 34 of the concentrator 3 is the OAM between the OLT and the ONU. Therefore, other functions for PON communication such as MPCP remain as functions of the PON processing unit 22 of ONU2A.
In order for the management control unit 34 to act for the OAM between the OLT and the ONU, the management control unit 34 needs to send and receive an OAM frame for which the OLT 1 manages the ONU2A.

Therefore, the PON processing unit 22 of the ONU2A performs "first processing" on the downlink OAM frame input from the optical transceiver 21 and outputs the processed frame to the PHY processing unit 23, so that the downlink transmitted by the OLT 1 is transmitted. OAM frame is relayed to the concentrator 3.
The first process includes a process of adding a management VLAN tag to a downlink OAM frame and a process of replacing the source address of the downlink OAM frame with the MAC address of the own device.

Further, when the destination of the upstream OAM frame input from the PHY processing unit 23 is the own device, the PON processing unit 22 of the ONU2A performs "second processing" on the upstream OAM frame to shift the processed frame. By outputting to the optical transceiver 21, the upstream OAM frame transmitted by the concentrator 3 is relayed to the OLT1.
In the second process, the VLAN tag is deleted from the uplink OAM frame and the destination address is rewritten to the specified address of the OAM protocol (multicast address for the slow protocol), and the source address of the uplink OAM frame is changed to the own device. It includes the process of replacing with a MAC address.

In order for the management control unit 34 to act for the OAM between the OLT and the ONU, it is necessary to determine which ONU2A is the OAM frame transmitted by the OLT1 as a management target. Therefore, the management control unit 34 collects in advance the address information (for example, MAC address) of the ONU2A that is connected to the concentrator 3 and can be operated.
Specifically, the management control unit 34 of the concentrator 3 independently establishes an OAM link for managing the ONU2A, triggered by the attachment of the pluggable ONU2A to its own device, and the OLT is subject to the establishment of this link. Act on behalf of the OAM link between / ONU.

That is, when two types of OAM links (control communication links) are defined as follows, the management control unit 34 establishes the OLT 1 and the second OAM link on condition that the ONU2A and the first OAM link are established.
1st OAM link: OAM link in which the own device tries to establish ONU2A as a management target. 2nd OAM link: OAM link in which OLT1 tries to establish ONU2A as a management target.

The management control unit 34 collects the address information of ONU2A by the control communication at the time of establishing the first OAM link, and records the management table 35 including the collected address information in the memory.
As shown in FIG. 2, the management table 35 is composed of tabular data including, for example, "entry", "port number", and "MAC address" columns. The "port number" is the number value of the physical ports P1 and P2 to which the ONU2A is mounted, and the "MAC address" is the MAC address value notified from the ONU2A.

Next, the management control unit 34 refers to the recorded management table 35 to establish a second OAM link instead of ONU2A.
Specifically, the management control unit 34 executes OAM discovery with OLT1 and establishes a second OAM link with OLT1. If the extended OAM frame after the establishment of the second OAM link contains the setting information of the ONU2A, the management control unit 34 transmits the acquired setting information to the ONU2A by the control communication after the establishment of the first OAM link. ..

[Procedure for the 1st OAM link]
FIG. 3A is a sequence diagram showing an example of the first OAM link executed by the management control unit 34. This monitoring process is executed for each physical port Pi. Further, the following message communication is performed in a predetermined management VLAN.

As shown in FIG. 3A, the PON processing unit 22 of the ONU2A transmits a connection request message to the management control unit 34 of the concentrator device 3 when it is attached to the physical port Pi of the slot-in method included in the concentrator device 3. (Step S11). The MAC address of the source of the connection request message is the address of ONU2A itself.

Upon receiving the connection request message, the management control unit 34 of the line concentrator 3 transmits a response message notifying the connection request message to the PON processing unit 22 of the ONU2A (step S12).
In this case, the management control unit 34 records the MAC address value and the port number value of ONU2A in the management table 35. After that, the PON processing unit 22 and the management control unit 34 are in a state where arbitrary information can be transmitted / received to / from ONU2A (step S13). That is, by establishing the first OAM link, the control communication between the PON processing unit 22 and the management control unit 34 is opened.

FIG. 3B is a sequence diagram showing another example of the first OAM link executed by the management control unit 34. This monitoring process is also executed for each physical port Pi.
As shown in FIG. 3B, the management control unit 34 of the concentrator 3 broadcasts the request message of the MAC address to the physical port Pi of the slot-in method every predetermined cycle (for example, 1 second) (step S21).

When the ONU2A is attached to a predetermined physical port Qi of the concentrator device 3, the PON processing unit 22 of the ONU2A transmits a response message including the MAC address of the own device to the management control unit 34 of the concentrator device 3 (step S22). ).
When the management control unit 34 of the line concentrator 3 succeeds in receiving the MAC address, the management control unit 34 transmits a response message notifying that fact to the PON processing unit 22 of the ONU2A (step S23).

In this case, the management control unit 34 records the received MAC address value and port number value in the management table 35. After that, the PON processing unit 22 and the management control unit 34 are in a state where arbitrary information can be transmitted / received to / from ONU2A (step S24). That is, by establishing the first OAM link, the control communication between the PON processing unit 22 and the management control unit 34 is opened.

[Link-up procedure for PON communication]
FIG. 4 is a sequence diagram showing an example of a link-up procedure for PON communication.
As shown in FIG. 4, OLT1 executes OAM discovery after the completion of P2MP link-up and attempts to establish a second OAM link in the PON communication section.
In this case, in the present embodiment, the PON processing unit 22 of the ONU2A executes the P2MP discovery, but the management control unit 34 of the concentrator 3 acts on behalf of the OAM discovery.

Specifically, when the PON processing unit 12 of the OLT 1 establishes an MPCP link with the ONU2A of a predetermined LLID, it transmits an Information OAM frame in which the predetermined information of its own station is described (step S31).
When the ONU2 is a normal ONU2B, the ONU2B responds to the Information OAM frame, but the PON processing unit 22 of the pluggable type ONU2A relays the Information OAM frame received from the OLT 1 to the concentrator 3 (step S32).

In the relay of the downlink OAM frame in step 32, the PON processing unit 22 of the pluggable type ONU2A attaches the tag of the management VLAN to the OAM frame and replaces the source address with its own MAC address (first process).

The management control unit 34 of the concentrator 3 that has received the Information OAM frame transmits the Information OAM frame in which the predetermined information of the ONU2A is described in the uplink (step S33).
In the transmission of the upstream OAM frame in step 33, the management control unit 34 of the concentrator 2 attaches the tag of the management VLAN to the Information OAM frame and designates the destination address as the MAC address of ONU2A.

The PON processing unit 22 of the pluggable type ONU2A relays the Information OAM frame received from the concentrator 3 to the OLT 1 (step S34).
In the relay of the uplink OAM frame in step 34, the PON processing unit 22 of the pluggable ONU2A deletes the tag of the management VLAN from the OAM frame, replaces the destination address with the specified address (multicast address for slow protocol), and transmits. Replace the original address with its own MAC address (second process).

If the OAM discovery using the Information OAM frame is successful, the OAM link (second OAM link) with the OLT1 is established, and thereafter, any OAM frame can be transmitted / received (SEND_ANY state).
That is, by establishing the second OAM link, the control communication between the OLT 1 and the management control unit 34 is opened. The same conversion processing (first and second processing) as in the above steps S32 and S34 is also executed in the relay of the OAM frame used for the control communication after opening.

When the OAM link is established, the PON processing unit 12 of the OLT 1 downlinks and transmits, for example, an extended OAM frame including the setting information of the ONU2A (step S35).
When the ONU2 is a normal ONU2B, the ONU2B responds to the extended OAM frame, but the PON processing unit 22 of the pluggable type ONU2A relays the extended OAM frame received from the OLT 1 to the concentrator 3 (step S36).

The management control unit 34 of the concentrator 3 that has received the extended OAM frame generates a control frame including the setting information of the ONU2A, and transmits the generated control frame to the ONU2A (step S37).
In this case, the management control unit 34 of the concentrator 3 determines the transmission destination of the control frame with reference to the management table 35. Therefore, when the setting information of a plurality of ONU2A is acquired from the OLT1, the setting information can be provided to an appropriate destination.

Upon receiving the control frame, the PON processing unit 12 of the ONU2A transmits the response frame to the concentrator 3 (step S38).
The transmission / reception of the control frame and the response frame in steps S37 and S38 is executed by the control communication opened by the establishment of the first OAM link.

The management control unit 34 of the concentrator 3 that has received the response frame transmits the extended OAM frame for response in the uplink (step S39). The transmission / reception of the extended OAM frame in steps 35 and 39 is executed by the control communication opened by the establishment of the second OAM link.
The PON processing unit 22 of the ONU2A relays the extended OAM frame received from the concentrator 3 to the OLT 1 (step S40).

[First modification]
FIG. 5 is an overall configuration diagram showing a first modification of the optical communication system.
As shown in FIG. 5, in the optical communication system according to the first modification, the radio base station used for mobile communication is located on the upper device 40, which is a signal processing unit located on the upper side, and on the lower side. It is separated into a lower device 50 which is an antenna unit, and a mobile front hole (MFH) which is an optical communication section is interposed between the upper device 40 and the lower device 50.

The host device 40 of the radio base station is, for example, a BBU (Base Band Unit). The lower device 50 of the radio base station is made of, for example, an RRH (Remote Radio Head). The lower device 50 is common to the above-mentioned user terminal 5 in that it is a communication node on the subscriber side of ONU2A.
Hereinafter, the upper device of the radio base station is referred to as "BBU", and the lower device of the radio base station is referred to as "RRH". The RRH 50 is capable of wireless communication with one or more mobile terminals 60 included in a communication cell (for example, a small cell) of its own device.

The BBU40 and the OLT1 are communicably connected by a predetermined communication cable (for example, an optical fiber).
The ONU2 comprises a pluggable ONU2A and is connected to a slot-in type physical port of the concentrator 3. The RRH50 is connected to the concentrator 3 by a predetermined communication cable (for example, a LAN cable).

In the modification of FIG. 5, among a plurality of ONU2A housed in the same OLT1 and connected to the same concentrator 3, some ONU2A are set as the working system and the remaining ONU2A is set as the backup system. ONU2A is made redundant.
By doing so, when the ONU2A of the current system fails, the route setting of the concentrator 3 is switched so as to connect the ONU2A of the backup system and the RRH50, so that the user communication by the RRH50 (mobile in the case of FIG. 5). Communication) protection can be achieved.

[Second modification]
FIG. 6 is an overall configuration diagram showing a second modification of the optical communication system.
As shown in FIG. 6, in the optical communication system according to the second modification, a plurality of OLT1s connected to an upper network, a plurality of ONU2s connected to the OLT1 by a PON line 4, and a concentrator to which a plurality of ONU2s are connected are connected. It includes a device 3 and a user terminal 5 connected to the line concentrator device 3.

The ONU2 comprises a pluggable ONU2A and is connected to a slot-in type physical port of the concentrator 3. The user terminal 5 is connected to the concentrator 3 by a predetermined communication cable (for example, a LAN cable).

In the modification of FIG. 6, among a plurality of ONU2A housed in separate OLT1s and connected to the same concentrator 3, some ONU2A are set as the active system and the remaining ONU2A are set as the spare system. , The PON line 4 is made redundant.
By doing so, when the OLT1 or ONU2A of the active PON line 4 fails, the route setting of the concentrator 3 is switched so as to connect the ONU2A of the standby PON line 4 to the user terminal 5. , It is possible to protect the user communication by the user terminal 5.

[Other variants]
The embodiments described above are exemplary in all respects and are not restrictive. The scope of rights of the present invention includes all modifications within the same scope as the configurations described in the claims.
For example, in the above-described embodiment, the ONU2A does not necessarily have to be a pluggable type, and may be an ONU2 of a type that is indirectly connected to a physical port of a communication device such as a concentrator 3 via a communication cable.

In the above-described embodiment, the case where the communication device to which the ONU2A can be connected is the concentrator device 3, but the communication device has at least one physical port Pi for ONU2A such as a home gateway (HGW) or a general-purpose server. It may be a communication device having.
In the above-described embodiment, when the communication device to which the ONU2A can be connected is a communication device such as a general-purpose server that does not connect to the user terminal 5, the physical port Qj for the user terminal (lower device) 5 becomes unnecessary.

<Additional notes on the features of the embodiment>
The embodiments described above include the features described below.

[Appendix 1]
It is a home-side device that constitutes a PON system together with a station-side device.
Optical transceiver and
The PON processing unit connected to the optical transceiver and
The PHY processing unit connected to the PON processing unit and
A terminal module connected to the PHY processing unit and capable of being directly or indirectly connected to a physical port of a communication device.
The PON processing unit is
Establish the following first OAM link with the communication device in which the management VLAN is set,
The first processing is performed on the downlink OAM frame input from the optical transceiver, the processed frame is output to the PHY processing unit, and the second processing is performed on the upstream OAM frame input from the PHY processing unit. A home-side device that causes the communication device to establish the following second OAM link by outputting the processed frame to the optical transceiver.
1st OAM link: OAM link in which the communication device tries to establish the home side device as a management target 2nd OAM link: OAM link in which the station side device tries to establish the home side device as a management target

[Appendix 2]
In the first process,
The process of adding a management VLAN tag to the downlink OAM frame,
The home-side device according to Appendix 1, which includes a process of replacing the source address of the downlink OAM frame with the MAC address of the own device.

[Appendix 3]
In the second process,
The process of deleting the management VLAN tag from the upstream OAM frame and replacing the destination address with the specified address of the OAM protocol.
The home-side device according to Appendix 1 or Appendix 2, which includes a process of replacing the source address of the upstream OAM frame with the MAC address of the own device.

1 OLT (station side device)
2 ONU (home side device)
2A Pluggable ONU (home side device)
2B stationary ONU (home side device)
3 Concentrator (communication device)
4 PON line 5 User terminal (lower device)
6 Optical splitter 7 Trunk fiber 8 Branch fiber 11 Optical transceiver (TRx)
12 PON processing unit 13 Switch unit 14 Management control unit 15 Management terminal 21 Optical transceiver (TRx)
22 PON processing unit 23 PHY processing unit 24 Terminal module 31 Upper side transmission / reception unit 32 Switch unit 33 Lower side transmission / reception unit 34 Management control unit 35 Management table 40 BBU (upper device)
50 RRH (lower device)
60 Mobile terminals P1, P2 …… Physical port Q1, Q2 …… Physical port

Claims (6)

A communication device that communicates with the home-side device that constitutes the PON system together with the station-side device.
One or more physical ports to which the home-side device can be connected,
A management control unit that manages the connected home-side device,
A relay processing unit that relays communication frames transmitted and received by the home-side device and the management control unit is provided.
The management control unit
A communication device that establishes the following second communication link with the station-side device, provided that the following first communication link is established with the home-side device.
1st communication link: Control communication link in which the communication device tries to establish the home side device as a management target 2nd communication link: Control communication link in which the station side device tries to establish the home side device as a management target The management control unit
The communication device according to claim 1, wherein the setting information of the home-side device is acquired by control communication with the station-side device opened by establishing the second communication link. The management control unit
The communication device according to claim 2, wherein the acquired setting information of the home-side device is transmitted to the home-side device by control communication with the home-side device opened by establishing the first communication link. The management control unit
The address information of the connected home-side device is acquired by the control communication at the time of establishing the first communication link, and the transmission destination of the acquired setting information of the home-side device is determined based on the acquired address information. The communication device according to claim 3. It is a home-side device that constitutes a PON system together with a station-side device.
Optical transceiver and
The PON processing unit connected to the optical transceiver and
The PHY processing unit connected to the PON processing unit and
A terminal module connected to the PHY processing unit and capable of being directly or indirectly connected to a physical port of a communication device.
The PON processing unit is
Establish the following first communication link with the communication device,
A home-side device that relays a control frame used to establish the second communication link without establishing the following second communication link with the station-side device.
1st communication link: Control communication link in which the communication device tries to establish the home side device as a management target 2nd communication link: Control communication link in which the station side device tries to establish the home side device as a management target A PON system including a station-side device, a plurality of home-side devices connected to the station-side device by a PON line, and a communication device to which all or part of the plurality of home-side devices are connected.
The home-side device connected to the communication device is
Instead of establishing the following second communication link with the station-side device, the control frame used to establish the second communication link is relayed.
The communication device is
A PON system that establishes the following second communication link with the station-side device on condition that the following first communication link is established with the home-side device connected to the own device.
1st communication link: Control communication link in which the communication device tries to establish the home side device as a management target 2nd communication link: Control communication link in which the station side device tries to establish the home side device as a management target

Images