JP7170584B2 - Master station side optical line terminating equipment, slave station side optical line terminating equipment and optical communication system - Google Patents

Description

The present invention relates to a master station side optical line terminating device, a slave station side optical line terminating device, and an optical communication system.

2. Description of the Related Art There is an optical communication system composed of a master station side optical line terminating device and a slave station side optical line terminating device. For example, a PON (Passive Optical Network) comprising an OLT (Optical Line Terminal) as a parent station side optical line terminating device including an OSU (Optical Subscriber Unit) and an ONU (Optical Network Unit) as a slave station side optical line terminating device. ) system.

In a PON system, an ONU establishes a logical link with an OSU to communicate. At least one MAC (Media Access Control) address is required for each ONU to establish a logical link. Normally, an ONU is shipped with as many MAC addresses as the number of logical links that the ONU corresponds to.

Here, as defined in IEEE Std 802.3 defined by IEEE (Institute of Electrical and Electronics Engineers), ONU MAC addresses are used to identify logical links. It is required that there is no duplication in a plurality of connected ONUs.

Normally, even if the hardware supports multiple logical links, when the ONU is shipped with firmware that is supposed to operate only one logical link, only one MAC address is written to the ONU. It was shipped in mint condition. Therefore, even if the firmware is updated to support multiple logical links during operation, the ONU cannot support multiple logical links because the required number of MAC addresses is not written.

On the other hand, in order to establish a plurality of logical links, a plurality of MAC addresses are originally required. Techniques for generating the required number of local MAC addresses from an address are described.

JP 2016-12823 A

However, although the technique described in Patent Document 1 can generate a plurality of local MAC addresses from one MAC address, depending on the local MAC address generation method, a plurality of ONUs connected to one OSU may generate MAC addresses may be duplicated.

Accordingly, it is an object of one or more aspects of the present invention to be able to assign MAC addresses to ONUs in a plurality of ONUs so that MAC addresses do not overlap.

According to one aspect of the present invention, a master station side optical line terminating device is connected to an optical fiber cable used for communicating with a plurality of slave station side optical line terminating devices. A first information containing information capable of specifying the number of logical links required by the target slave station side optical line terminating equipment from the target slave station side optical line terminating equipment which is one of the slave station side optical line terminating equipment an optical/electrical converter that receives an optical signal including a control frame and converts the received optical signal into an electrical signal; a demultiplexer that demultiplexes the first control frame from the converted electrical signal ; a plurality of optical communication devices each including a logical link control unit that specifies the number of logical links from a first control frame; a storage unit that stores a plurality of MAC addresses; and based on the specified number of logical links, Even if the MAC address overlaps with the MAC address used in the plurality of optical communication devices except for one optical communication device connected to the target slave station side optical line terminating device among the plurality of optical communication devices, At least one MAC address is selected from the plurality of MAC addresses so as not to duplicate any MAC address used in the plurality of slave station side optical line terminating devices connected to the one optical communication device . and a MAC address processing unit, wherein the logical link control unit generates a second control frame including the selected at least one MAC address, and the demultiplexing unit multiplexes the second control frame. By doing so, an electrical signal is generated, and the opto-electric conversion unit converts the generated electrical signal into an optical signal, and transmits the converted optical signal to the target slave station side optical network terminal. characterized by

A slave station side optical line terminating device according to one aspect of the present invention is a slave station side optical line terminating device that communicates with the master station side optical line terminating device via an optical fiber cable connected to the master station side optical line terminating device. a logical link control unit which is a terminating device and generates a first control frame including information capable of specifying the number of logical links required for communication with the master station side optical line terminating device; a demultiplexer that generates an electrical signal by multiplexing one control frame; a demultiplexing unit that converts the generated electrical signal into an optical signal; and transmits the converted optical signal to the master station side optical network terminal. and an optical-electrical conversion unit connected to the master station-side optical network unit based on the number of logical links. Other slave station optical line sharing the optical fiber cable with said slave station optical line terminating equipment even if it overlaps with the MAC address used in other slave station optical circuit terminating equipment that does not share the optical fiber cable receiving an optical signal including a second control frame including at least one MAC address selected in the master station side optical network terminal so as not to duplicate MAC addresses used in the terminal equipment; The demultiplexer demultiplexes the second control frame from the converted electrical signal, and the logical link controller is included in the second control frame. At least one logical link is constructed with the master station side optical line terminating equipment via the optical/electrical conversion unit and the demultiplexing unit using the at least one MAC address.

An optical communication system according to an aspect of the present invention includes a master station side optical line terminating device, and a plurality of optical fiber cables sharing one of the plurality of optical fiber cables connected to the master station side optical line terminating device. An optical communication system comprising a slave station side optical line terminating device, wherein a target slave station side optical line terminating device is any one of the plurality of slave station side optical line terminating devices. a slave station side logical link control unit for generating a first control frame containing information capable of specifying the number of logical links required for communication with the master station side optical network terminal; by multiplexing the control frame, a slave station side demultiplexing unit that generates a first electrical signal; a slave station side demultiplexer that converts the first electrical signal into a first optical signal; a sub-station optical-to-electrical conversion unit for transmitting to the optical network terminal at the central office, wherein the optical network terminal at the central office is connected to the one optical fiber cable and receives the first optical signal; a master station optical/electrical converter that converts the first optical signal into a second electrical signal; a master station side demultiplexer that demultiplexes the first control frame from the second electrical signal ; a plurality of optical communication devices each including a parent station side logical link control unit that specifies the number of logical links from one control frame; a storage unit that stores a plurality of MAC addresses; and overlaps with the MAC address used in the plurality of optical communication devices except for one optical communication device among the plurality of optical communication devices that is connected to the target slave station side optical line terminating device. at least one MAC address from the plurality of MAC addresses so as not to overlap with any of the MAC addresses used in the plurality of slave station side optical line terminating devices connected to the one optical communication device. a selecting MAC address processing unit, wherein the parent station side logical link control unit generates a second control frame including the selected at least one MAC address, and the parent station side demultiplexing unit A third electrical signal is generated by multiplexing the second control frame, and the master station side optical-electrical conversion unit converts the third electrical signal into a second optical signal, and converts the third electrical signal into a second optical signal. to the target slave station side optical line terminating device, the slave station side optical-electrical conversion unit receives the second optical signal, converts the second optical signal into a fourth electrical signal The slave station side demultiplexing unit demultiplexes the second control frame from the fourth electrical signal, and the slave station side logic relay The link control unit uses the at least one MAC address included in the second control frame to transmit the master station side It is characterized by building at least one logical link with the optical line terminating equipment.

According to one or more aspects of the present invention, MAC addresses can be assigned to ONUs so that MAC addresses do not overlap among multiple ONUs.

1 is a block diagram schematically showing the configuration of a PON system according to Embodiment 1; FIG. FIG. 4 is a sequence diagram showing logical link construction operations of ONUs in the PON system; 2 is a block diagram schematically showing the configuration of an ONU according to Embodiment 1; FIG. (A) and (B) are schematic diagrams showing hardware configuration examples. 4 is a schematic diagram showing a MAC address management table according to Embodiment 1; FIG. 2 is a block diagram schematically showing the configuration of an OSU according to Embodiment 1; FIG. FIG. 4 is a sequence diagram showing operations for building a logical link between an ONU and an OLT in Embodiment 1; 4 is a flow chart showing the operation of a logical link control unit of an ONU; 2 is a block diagram schematically showing the configuration of a PON system according to Embodiment 2; FIG. FIG. 10 is a block diagram schematically showing the configuration of an OSU according to Embodiment 2; FIG. FIG. 10 is a schematic diagram showing a MAC address management table according to Embodiment 2; FIG. FIG. 12 is a sequence diagram showing operations for building a logical link between an ONU and an OSU in the second embodiment;

Embodiment 1.
FIG. 1 is a block diagram schematically showing the configuration of a PON system 100, which is an optical communication system according to Embodiment 1. As shown in FIG.
The PON system 100 comprises a plurality of ONUs 110 and an OLT 130 .

As shown in FIG. 1 , the OLT 130 includes multiple OSUs 140 , and multiple ONUs 110 are connected to one OSU 140 via optical fiber cables 101 and optical splitters 102 . The OLT 130 functions as a master station side optical network terminal.

The OLT 130 transmits data received from the host network (hereinafter referred to as downstream data) to the ONU 110 and data received from the ONU 110 (hereinafter referred to as upstream data) to the host network. Also, the OLT 130 issues a MAC address to the ONU 110 upon request from the ONU 110 .

The ONU 110 transmits downstream data received from the OSU 140 to the user network and data received from the user network to the OSU 140 . The ONU 110 functions as a slave station side optical network terminal.

Here, in FIG. 1, as a configuration of the PON system 100, a plurality of OSUs 140 are accommodated in the OLT 130, and a plurality of ONUs 110 are connected to one OSU 140. In other words, one OSU 140 is connected to one ONU 110. Although an example in which a plurality of ONUs 110 share the optical fiber cable 101 is shown, the number of OSUs 140 may be one or more, and the number of ONUs 110 may be one or more.

FIG. 2 is a sequence diagram showing the logical link construction operation of the ONU 110 in the PON system 100. As shown in FIG.
First, the OSU 140 transmits a Discovery GATE frame, which is a GATE frame containing Discovery Information, to the ONU 110 and notifies the ONU 110 of transmission timing (S10).

Next, when the ONU 110 receives the Discovery GATE frame, it transmits a REGISTER REQ frame, which is a registration request from the ONU 110 (S11).
Next, in response to receiving the REGISTER REQ frame, the OSU 140 newly registers the LLID, which is the identifier of the ONU 110 that transmitted the REGISTER REQ frame, and transmits the REGISTER frame for notifying the ONU 110 of the registered LLID ( S12).

Next, the OSU 140 transmits a Normal GATE frame for notifying the ONU 110 of the transmission band and transmission timing (S13).
Next, the ONU 110 returns a REGISTER ACK frame with the transmission band and transmission timing obtained in step S13 (S14).

In steps S10 to S14 described above, the MPCP Discovery sequence, which is an operation for constructing a logical link, is realized and the logical link is established (S15).

Here, the Discovery Gate frame, Register Req frame, Register frame, Normal Gate frame, and Register Ack frame are GE-PON control frames defined by the IEEE802.3 standard. In the MPCP Discovery sequence, a MAC address is required for transmitting and receiving a series of control frames. Here, the control frame transmitted from the ONU 110 is also called the first control frame, and the control frame transmitted from the OLT 130 is also called the second control frame.

After establishing the logical link (S15), the ONU 110 and the OSU 140 periodically exchange Information OAM frames (S16, S17) to monitor each other's health.

FIG. 3 is a block diagram schematically showing the configuration of ONU 110 according to the first embodiment.
The ONU 110 includes an opto-electric conversion section 111, a demultiplexing section 112, a frame processing section 113, a user network interface section (hereinafter referred to as a user network I/F section) 114, a logical link control section 115, and a storage section 116. and

The optical/electrical converter 111 converts the optical signal of the downstream data received from the OSU 140 into an electrical signal, and supplies the downstream data to the demultiplexer 112 .
Further, the opto-electric converter 111 converts the electric signal of the upstream data given from the demultiplexer 112 into an optical signal and transmits the optical signal to the OSU 140 .
Note that the opto-electric conversion unit 111 is also referred to as a child station side opto-electric conversion unit. The opto-electric conversion unit 111 can be composed of an optical communication interface.

The demultiplexing unit 112 demultiplexes the downstream data given from the optical/electrical converting unit 111 into user frames and control frames (GATE frames, OAM frames, etc.) related to the PON protocol. Demultiplexing section 112 then gives the user frame to frame processing section 113 and gives the control frame to logical link control section 115 .
Further, the demultiplexing unit 112 multiplexes the user frame given from the frame processing unit 113 and the control frame (Report frame, OAM frame, etc.) related to the PON protocol given from the logical link control unit 115, and It is sent to the conversion unit 111 as upstream data.
Note that the demultiplexing unit 112 is also called a slave station side demultiplexing unit.

Further, according to the logical link state given from the logical link control section 115, the demultiplexing section 112 stops passing user frames to and from the frame processing section 113 when no logical link is established with the OSU 140. . On the other hand, demultiplexing section 112 transfers user frames to and from frame processing section 113 when a logical link has been established with OSU 140 according to the logical link state given from logical link control section 115 . .

Frame processing section 113 generates a user transmission frame by converting the user frame given from demultiplexing section 112 into a data format used in the user network, and transmits the user transmission frame to user network I/F section 114. give.
Also, the frame processing unit 113 converts the user received frame given from the user network I/F unit 114 into a data format used in the PON system 100 to generate a user frame, and demultiplexes the user frame. 112.
Note that the frame processing unit 113 is also referred to as a child station side frame processing unit.

The user network I/F unit 114 converts the user transmission frame given from the frame processing unit 113 into a user transmission signal, which is a signal in the signal format used in the user network, and transmits the user transmission signal to the user network. Communication interface.
Also, the user network I/F unit 114 receives a user reception signal from the user network and converts the user reception signal into an electric signal, which is a signal format used inside the ONU 110, thereby generating a user reception frame. do. Then, user network I/F section 114 gives the user received frame to frame processing section 113 .
The signal format used in the user network may be an electrical signal or an optical signal.

The logical link control unit 115 transmits and receives control frames (Gate frame, Report frame, OAM frame, etc.) related to the PON protocol, and establishes a logical link with the OSU 140 . Here, the number of logical links to be established with the OSU 140 may be one or plural. For example, the logical link control section 115 establishes a logical link with the OSU 140 using the MAC address stored in the storage section 116 .
Note that the logical link control unit 115 is also called a child station side logical link control unit.

Specifically, the logical link control unit 115 uses one MAC address set in the ONU 110 in advance to construct a basic logical link, which is the first logical link to be constructed with the OLT 130 .
Then, the logical link control unit 115 generates a control frame containing information capable of specifying the number of logical links required for communication with the OLT 130, and sends the control frame to the demultiplexing unit 112 and the optical/electrical conversion unit. It is sent to the OLT 130 via the unit 111 .

Based on the number of logical links sent to the OLT 130 via the optical/electrical conversion unit 111 and the demultiplexing unit 112, the logical link control unit 115 connects the ONU 110 and the other ONU 110 sharing the optical fiber cable connected to the OLT 130. Obtain a control frame containing at least one MAC address selected by the OLT 130 so as not to duplicate MAC addresses in use.

Then, the logical link control unit 115 establishes at least one logical link with the OLT 130 via the optical/electrical conversion unit 111 and the demultiplexing unit 112 using at least one MAC address included in the acquired control frame. To construct.

The storage unit 116 stores programs and information necessary for processing in the ONU 110 . For example, the storage unit 116 stores MAC addresses used by the ONUs 110 .
Storage unit 116 includes nonvolatile memory 117 and volatile memory 118 .

The nonvolatile memory 117 stores software programs and parameters necessary for the operation of the ONU 110 . In this embodiment, the nonvolatile memory 117 is written with one MAC address necessary for constructing a logical link.

The volatile memory 118 is used as a work memory for the logical link control unit 115, and is used for executing programs read from the nonvolatile memory 117 and storing temporarily used parameters and the like. In this embodiment, the MAC address obtained from the OLT 130 is written in the volatile memory 118 .

Part or all of the demultiplexing unit 112, the frame processing unit 113, and the logical link control unit 115 described above may be, for example, a single circuit, a composite circuit, or a program, as shown in FIG. processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array).

Part or all of the demultiplexing unit 112, the frame processing unit 113 and the logical link control unit 115 are stored in the memory 11 and the memory 11 as shown in FIG. 4B, for example. It can be configured with a processor 12 such as a CPU (Central Processing Unit) that executes a program. Such a program may be provided through a network, or recorded on a recording medium and provided. That is, such programs may be provided as program products, for example.

As shown in FIG. 1, the OLT 130 comprises a MAC address pool 131, a MAC address processing unit 132, and multiple OSUs 140. FIG.
The MAC address pool 131 functions as a storage unit that stores multiple MAC addresses to be issued to the ONUs 110 . For example, the MAC address pool 131 stores MAC address management information for managing MAC addresses issued to the ONUs 110 .

FIG. 5 is a schematic diagram showing the MAC address management table 119 as an example of MAC address management information.
The MAC address management table 119 shown in FIG. 5 has an entry number column 119a, a MAC address column 119b, and an issue status column 119c. In the MAC address management table 119, one row corresponds to one entry, and one entry manages one MAC address.

The entry number column 119a stores entry numbers, which are entry identification information for identifying entries.
The MAC address column 119b stores MAC addresses.
The issue status column 119c stores information indicating the issue status of the MAC address. The payout status column 119c includes an OSU number column 119d and an ONU number column 119e.

The OSU number column 119d is provided with individual columns corresponding to each of the plurality of OSU numbers assigned to each of the plurality of OSUs 140 in order to identify each of the plurality of OSUs 140, and a check mark is added to the individual column. This indicates that the OSU 140 corresponding to that individual column uses the MAC address stored in the MAC address column 119b of the same entry.
The ONU number column 119e stores an ONU number, which is ONU identification information for identifying the ONU 110 using the MAC address stored in the MAC address column 119b of the same entry. It is assumed that the ONU 110 is assigned an ONU number for identifying the ONU 110 . For example, the ONU number can be generated from the MAC address used by the ONU 110 to construct the basic logical link, or from the OSU number to which the ONU 110 is connected and the LLID corresponding to the ONU 110 basic logical link.

As described above, according to the MAC address management table 119, the MAC address, the ONU 110 using the MAC address, and the OSU 140 to which the ONU 110 is connected can be associated.

Returning to FIG. 1, the MAC address processing unit 132 refers to the MAC address management information based on the number of logical links required by the ONU 110 in response to a request from the ONU 110, and Choose MAC addresses so that they do not overlap.

OSU 140 is an optical communication device that performs communication with ONU 110 .
FIG. 6 is a block diagram schematically showing the configuration of OSU 140 according to the first embodiment.
The OSU 140 includes an opto-electric conversion section 141 , a demultiplexing section 142 , a frame processing section 143 , a higher network interface section (hereinafter referred to as a higher network I/F section) 144 , and a logical link control section 145 .

The optical/electrical converter 141 converts the optical signal of the upstream data received from the ONU 110 into an electrical signal, and supplies the upstream data to the demultiplexer 142 .
The optical/electrical conversion unit 141 also converts the electrical signal of the downstream data given from the demultiplexing unit 142 into an optical signal, and transmits the downstream data of the optical signal to the ONU 110 .
Note that the opto-electric conversion unit 141 is also referred to as a parent station side opto-electric conversion unit. The opto-electric converter 141 can be composed of an optical communication interface.

The demultiplexer 142 demultiplexes the upstream data received from the optical/electrical converter 141 into a user frame and a control frame related to the PON protocol. It is given to the control unit 145 .
Further, the demultiplexing unit 142 multiplexes the user frame given from the frame processing unit 143 and the control frame related to the PON protocol given from the logical link control unit 145, and sends the data to the opto-electric conversion unit 141 as downstream data. give.
Note that the demultiplexing unit 142 is also called a parent station side demultiplexing unit.

Further, according to the logical link state given from the logical link control unit 145, the demultiplexing unit 142 stops passing user frames to and from the frame processing unit 143 when no logical link is established with the ONU 110. .
On the other hand, according to the logical link state given from the logical link control unit 145, the demultiplexing unit 142 transfers the user frame to the frame processing unit 143 when a logical link is established with the ONU 110. .

The frame processing unit 143 converts the user frame given from the demultiplexing unit 142 into a data format used in the upper network to generate an upper transmission frame, and transmits the upper transmission frame to the upper network I/F unit 144. give.
Further, the frame processing unit 143 converts the upper received frame given from the upper network I/F unit 144 into a data format used in the PON system 100 to generate a user frame, and demultiplexes the user frame. 142.
Note that the frame processing unit 143 is also called a parent station side frame processing unit.

The upper network I/F unit 144 converts the upper transmission frame given from the frame processing unit 143 into an upper transmission signal, which is a signal in the signal format used in the upper network, and transmits the upper transmission signal to the upper network. .
The upper network I/F unit 144 receives an upper received signal from the upper network and converts the received upper signal into an electrical signal in the signal format used inside the OSU 140 to generate an upper received frame. Then, upper network I/F section 144 provides the upper received frame to frame processing section 143 .
The signal format used in the host network may be an electrical signal or an optical signal.

The logical link control unit 145 passes control frames relating to the PON protocol and builds a logical link with the ONU 110 .
Further, the logical link control unit 145 gives the number of logical links notified from the ONU 110 to the MAC address processing unit 132, causes the MAC address to be paid out from the MAC address pool 131 of the OLT 130, and transmits the MAC address to the ONU 110 as a control frame. Use to notify.
Note that the logical link control unit 145 is also called a parent station side logical link control unit.

Specifically, the logical link control unit 145 constructs a basic logical link, which is the first logical link to be constructed with the ONU 110 via the optical/electrical conversion unit 141 and the demultiplexing unit 142 . Then, the logical link control unit 145 acquires from the ONU 110 a control frame containing information that can specify the number of logical links required by the ONU 110 .

Then, the logical link control unit 145 notifies the MAC address processing unit 132 of the number of logical links. Based on the number of logical links, the MAC address processing unit 132 stores the MAC addresses stored in the MAC address pool 131 so as not to duplicate any of the MAC addresses used by the plurality of ONUs 110 connected to the corresponding OSU 140 . select at least one MAC address from a plurality of MAC addresses in the

The logical link control unit 145 generates a control frame containing at least one MAC address selected by the MAC address processing unit 132, and sends the control frame to the ONU 110 via the demultiplexing unit 142 and the optical/electrical conversion unit 141. send.

A part or all of the MAC address processing unit 132, the demultiplexing unit 142, the frame processing unit 143, and the logical link control unit 145 described above may be, for example, a processing circuit as shown in FIG. 10.
Further, part or all of the MAC address processing unit 132, the demultiplexing unit 142, the frame processing unit 143, and the logical link control unit 145 are, for example, as shown in FIG. and a processor 12 that executes a program stored in 11 . Such a program may be provided through a network, or recorded on a recording medium and provided. That is, such programs may be provided as program products, for example.
Note that the MAC address pool 131 can be configured by a non-volatile memory or the like.

Next, the operation will be explained.
FIG. 7 is a sequence diagram showing operations for building a logical link between the ONU 110 and the OLT 130 in the first embodiment.
The ONU 110 can establish multiple logical links with the OSU 140, but assumes that ONU 110 only has the MAC address for logical link #1. Here is an example of building four logical links.
Here, the logical link #1 is the first logical link constructed between the ONU 110 and the OSU 140, and is also called a basic logical link. Also, the ONU 110 requesting the MAC address is also called a target slave station side optical line terminating device.

First, the logical link control unit 115 of the ONU 110 reads the MAC address for the logical link #1 from the nonvolatile memory 117 (S20).
Next, the logical link control unit 115 uses the MAC address read in step S20 to construct a logical link #1 between the OLT 130 and the OSU 140 according to the MPCP Discovery sequence (S21). The MPCP Discovery sequence has been described using FIG.

When the logical link #1 is established, the OSU 140, for example, sends an Information OAM frame to the ONU 110 (S22), as described with reference to FIG. 2, to perform life and death monitoring. In addition, in FIG. 7, the Information OAM frame is simply described as "Info OAM".

Then, the logical link control unit 115 notifies the number of logical links to the OSU 140 using an Information OAM frame, which is one of monitoring and control channels in GE-PON defined by the IEEE802.3 standard (S23).

Here, logical link control section 115 generates a control frame containing information that can specify the number of required logical links, and gives the control frame to demultiplexing section 112 . The demultiplexing unit 112 multiplexes the control frame to generate a first electrical signal, and supplies the first electrical signal to the photoelectric conversion unit 111 . The photoelectric converter 111 converts the first electrical signal into a first optical signal and outputs the first optical signal to the optical fiber cable 101 .

In the OSU 140 that receives the first optical signal from the ONU 110 , the optical/electrical converter 141 converts the first optical signal into a second electrical signal, and sends the second electrical signal to the demultiplexer 142 . give. Demultiplexing section 142 separates a control frame containing the number of logical links from the second electrical signal and gives it to logical link control section 145 .

The logical link control unit 145 notifies the MAC address processing unit 132 of the number of logical links included in the control frame given from the demultiplexing unit 142 . The MAC address processing unit 132 identifies the number of logical links required by the ONU 110 (here, 3) from the number of logical links, and selects the MAC address "MAC# A”, “MAC#B” and “MAC#C” are issued and given to the logical link control unit 145 . At this time, the MAC address processing unit 132 refers to the MAC address management table 119 shown in FIG. 5 to select the MAC address so that the OSU 140 that received the frame in step S23 does not duplicate the MAC address. Then, a check mark is added to the corresponding column of the OSU number column 119d, and the ONU number of the ONU 110 that transmitted the frame in step S23 is stored in the corresponding column of the ONU number column 119e. Then, the logical link control unit 145 notifies the MAC addresses for the logical links #2 to #4 to the ONU 110 through the logical link #1 using the Information OAM frame (S24).

Here, the logical link controller 145 generates a control frame including the MAC address selected by the MAC address processor 132 and gives the control frame to the demultiplexer 142 . The demultiplexing unit 142 multiplexes the control frame to generate a third electrical signal, and supplies the third electrical signal to the photoelectric conversion unit 111 . The photoelectric converter 111 converts the third electrical signal into a second optical signal and outputs the second optical signal to the optical fiber cable 101 .

In the ONU 110 that has received the second optical signal from the OLT 130, the optical/electrical converter 111 converts the second optical signal into a fourth electrical signal, and sends the fourth electrical signal to the demultiplexer 112. give. Demultiplexing section 112 separates the control frame including the MAC address from the fourth electrical signal and gives it to logical link control section 115 .

The logical link control unit 115 of the ONU 110 that has received the MAC addresses of the logical links #2 to #4 stores the MAC addresses "MAC#A", "MAC#B" and "MAC#C" in the volatile memory 118 (S25 ).
After storing the MAC address received from the OSU 140 in the volatile memory 118, the logical link control unit 115 notifies the OSU 140 that the MAC address has been received using an Information OAM frame (S26).

Next, the logical link control unit 115 reads the MAC addresses "MAC#A", "MAC#B" and "MAC#C" from the volatile memory 118 (S27, S28, S29).
Then, the logical link control unit 115 constructs the logical link #2 through the MPCP Discovery sequence using the MAC address "MAC#A" (S30).

Also, the logical link control unit 115 uses the MAC address “MAC#B” to construct logical link #3 through the MPCP Discovery sequence (S31).
Further, the logical link control unit 115 uses the MAC address "MAC#C" to construct logical link #4 through the MPCP Discovery sequence (S32).

The MAC addresses "MAC#A", "MAC#B" and "MAC#C" stored in the volatile memory 118 are continuously used while the logical link #1 is valid. When the logical link #1 is disconnected, the logical link control unit 115 erases the MAC addresses "MAC#A", "MAC#B" and "MAC#C" from the volatile memory 118, and restarts the logical link #1. Start with a build operation of 1. In other words, MAC addresses "MAC#A", "MAC#B" and "MAC#C" are available only when logical link #1 is enabled.

Although FIG. 7 illustrates a case where the number of logical links is four, any number of logical links can be applied.

FIG. 8 is a flow chart showing the operation of the logical link controller 115 of the ONU 110 according to the first embodiment.
The logical link control unit 115 reads from the nonvolatile memory 117 the MAC address for the basic logical link, which is the first logical link to be established with the OLT 130 (S40).
Then, the logical link control unit 115 constructs a basic logical link with the OSU 140 through the MPCP Discovery sequence (S41).

Then, the logical link control unit 115 determines whether or not construction of the basic logical link is completed (S42). Then, when the construction of the basic logical link is completed (Yes in S42), the process proceeds to step S43.

At step S43, the logical link controller 115 notifies the OSU 140 of the required number of logical links using the Information OAM frame (S43).
Then, the logical link control unit 115 determines whether or not the MAC address necessary for building the logical link has been received from the OSU 140 (S44). If the MAC address has been received (Yes in S44), the process proceeds to step S45.

At step S45, the logical link control unit 115 stores the received MAC address in the volatile memory 118. FIG.
Then, the logical link control unit 115 notifies the OSU 140 that the MAC address has been received using an Information OAM frame (S46).

Next, the logical link control unit 115 determines whether or not a basic logical link has been established with the OSU 140 (S47). The logical link control unit 115 can make this determination through the life-and-death monitoring described in steps S16 and S17 of FIG. If the basic logical link has been established (Yes in S47), the process proceeds to step S48, and if the basic logical link has not been established (No in S47), the process proceeds to step S51.

At step S<b>48 , the logical link control unit 115 reads the MAC address notified from the OSU 140 from the volatile memory 118 .
Then, the logical link control unit 115 uses the read MAC address to construct an additional logical link through the MPCP Discovery sequence (S49).

Next, the logical link control unit 115 determines whether or not a basic logical link has been established with the OSU 140 (S50). If the basic logical link has not been established (No in S50), the process proceeds to step S51.

At step S51, the logical link control unit 115 erases the MAC address stored at step S45 from the volatile memory 118. FIG. The process then returns to step S40.

As described above, according to Embodiment 1, ONU 110 notifies OSU 140 of the number of logical links, and OSU 140 issues MAC addresses to ONU 110 according to the contents of the notification from ONU 110. Even if there is only one MAC address, multiple logical links can be constructed.

Also, since the OSU 140 is configured to issue the MAC address to the ONU 110, the OSU 140 side can manage MAC addresses so that they do not overlap.

Furthermore, since the MAC address received from the OSU 140 is erased from the volatile memory 118 when the basic logical link disappears, even if the ONU 110 is powered on and reconnected to another OLT, another Since the MAC address is acquired again with the OLT, problems such as MAC address duplication can be avoided.

Embodiment 2.
FIG. 9 is a block diagram schematically showing the configuration of PON system 200 according to the second embodiment.
The PON system 200 comprises a plurality of ONUs 110 and an OLT 230 .
ONU 110 in PON system 200 in the second embodiment is the same as ONU 110 in PON system 100 in the first embodiment.

As shown in FIG. 9 , the OLT 230 has multiple OSUs 240 , and multiple ONUs 110 are connected to one OSU 240 via optical fiber cables 101 and optical splitters 102 .

Here, FIG. 9 shows an example in which a plurality of OSUs 240 are accommodated in the OLT 230 and a plurality of ONUs 110 are connected to one OSU 240 as the configuration of the PON system 200. However, the number of OSUs 240 is one or more. The number of ONUs 110 may be one or more.

FIG. 10 is a block diagram schematically showing the configuration of OSU 240 according to the second embodiment.
The OSU 240 includes an optical/electrical conversion unit 141, a demultiplexing unit 142, a frame processing unit 143, an upper network I/F unit 144, a logical link control unit 245, a MAC address processing unit 246, and a MAC address pool 247. Prepare.

The optical/electrical conversion unit 141, the demultiplexing unit 142, the frame processing unit 143, and the upper network I/F unit 144 of the OSU 240 in Embodiment 2 are the same as the optical/electrical conversion unit 141, the demultiplexing unit 142, It is similar to the frame processing unit 143 and the upper network I/F unit 144 .

In the first embodiment, the OLT 130 is provided with the MAC address pool 131, and the MAC address is issued from the MAC address pool 131 according to the notification from the logical link control unit 145 of each OSU 140. However, in the second embodiment, the OLT 230 is A MAC address processing unit 246 and a MAC address pool 247 are provided in the OSU 240 .

The logical link control unit 245 passes control frames relating to the PON protocol and builds a logical link with the ONU 110 .
In addition, the logical link control unit 245 gives the number of logical links notified from the ONU 110 to the MAC address processing unit 246, dispenses the MAC address from the MAC address pool 247, and sends the MAC address to the ONU 110 using the control frame. give notice.
Note that the logical link control unit 245 is also called a parent station side logical link control unit.

The MAC address processing unit 246 generates MAC addresses used in the OSU 240 for the maximum number of logical links that the OSU 240 can accommodate, based on the OSU 240 mounting location information (for example, slot number, etc.). Then, the MAC address processing unit 246 generates MAC address management information to be described later, stores it in the MAC address pool 131, and stores the logical link construction status (for example, established and not established) of the ONU 110 and the MAC address to the ONU 110. Manage payout status.
The MAC address processing unit 246 dispenses MAC addresses from the MAC address pool 247 according to the number of logical links given from the logical link control unit 245 so as not to overlap in the connected ONUs 110 .

The MAC address pool 247 functions as a MAC address storage unit that stores MAC addresses issued to the ONUs 110 . For example, the MAC address pool 131 stores MAC address management information for managing MAC addresses issued to the ONUs 110 .

FIG. 11 is a schematic diagram showing a MAC address management table 248 as an example of MAC address management information.
The MAC address management table 248 shown in FIG. 11 has an entry number column 248a, a MAC address column 248b, and an issue status column 248c. In the MAC address management table 248, one row corresponds to one entry, and one entry manages one MAC address.

The entry number column 248a stores entry numbers, which are entry identification information for identifying entries.
The MAC address column 248b stores MAC addresses.
The issue status column 248c stores information indicating the issue status of the MAC address. Here, whether or not the corresponding MAC address is used, in other words, whether or not the corresponding MAC address is issued, and the ONU number of the ONU 110 using the corresponding MAC address are stored. .

As described above, according to the MAC address management table 248, a MAC address can be associated with the ONU 110 using that MAC address.

A part or all of the demultiplexing unit 142, the frame processing unit 143, the logical link control unit 245, and the MAC address processing unit 246 described above is, for example, a processing circuit as shown in FIG. 10.
Also, some or all of the demultiplexing unit 142, the frame processing unit 143, the logical link control unit 245, and the MAC address processing unit 246 are, for example, as shown in FIG. and a processor 12 that executes a program stored in 11 . Such a program may be provided through a network, or recorded on a recording medium and provided. That is, such programs may be provided as program products, for example.
Note that the MAC address pool 247 can be configured by a non-volatile memory or the like.

Next, the operation will be explained.
FIG. 12 is a sequence diagram showing the operation of building a logical link between ONU 110 and OSU 240 in the second embodiment. Here, the ONU 110 requesting the MAC address is also referred to as the target slave station side optical line terminating equipment.
The ONU 110 can establish multiple logical links with the OSU 240, but only has the MAC address for the logical link #1. Here is an example of building four logical links.
Also, the MAC address processing unit 246 of the OSU 240 generates as many MAC addresses as the number of links that the OSU 240 can accommodate when the OSU 240 is activated, and stores them in the MAC address pool 247 .

First, the logical link control unit 115 of the ONU 110 reads the MAC address for the logical link #1 from the nonvolatile memory 117 (S60).
Next, the logical link control unit 115 uses the MAC address read in step S60 to construct a logical link #1 with the OSU 240 according to the MPCP Discovery sequence (S61).

When the logical link #1 is established, the OSU 240, for example, sends an Information OAM frame to the ONU 110 (S62), as described with reference to FIG. 2, to perform life and death monitoring. In addition, in FIG. 12, the Information OAM frame is simply described as "Info OAM".

Then, the logical link control unit 115 notifies the number of logical links to the OSU 240 using the Information OAM frame (S63).
Here, logical link control section 115 generates a control frame containing information that can specify the number of required logical links, and gives the control frame to demultiplexing section 112 . The demultiplexing unit 112 multiplexes the control frame to generate a first electrical signal, and supplies the first electrical signal to the photoelectric conversion unit 111 . The photoelectric converter 111 converts the first electrical signal into a first optical signal and outputs the first optical signal to the optical fiber cable 101 .

In the OSU 140 that receives the first optical signal from the ONU 110 , the optical/electrical converter 141 converts the first optical signal into a second electrical signal, and sends the second electrical signal to the demultiplexer 142 . give. The demultiplexing unit 142 separates a control frame containing the number of logical links from the second electrical signal and gives it to the logical link control unit 245 .

The logical link control unit 245 that has acquired the control frame from the demultiplexing unit 142 notifies the MAC address processing unit 246 of the number of logical links. The MAC address processing unit 246 issues MAC addresses “MAC#A”, “MAC#B” and “MAC#C” for the logical links #2 to #4 from the MAC address pool 247, and transfers them to the logical link control unit. Give to 245. At this time, the MAC address processing unit 246 refers to the MAC address management table 248 shown in FIG. 11 to select the MAC address whose payout status column 248c is "unused". Thereby, the MAC address processing unit 246 selects MAC addresses so that MAC addresses do not overlap. Note that the MAC address processing unit 246 updates the column of the issued MAC address in the issued status column 248c to "in use" and stores the ONU number of the ONU 110 in use. Then, the logical link control unit 245 notifies the MAC addresses for the logical links #2 to #4 to the ONU 110 through the logical link #1 using the Information OAM frame (S64).

Here, the logical link control unit 245 generates a control frame containing the MAC address selected by the MAC address processing unit 246 and gives the control frame to the demultiplexing unit 142 . The demultiplexing unit 142 multiplexes the control frame to generate a third electrical signal, and supplies the third electrical signal to the photoelectric conversion unit 111 . The photoelectric converter 111 converts the third electrical signal into a second optical signal and outputs the second optical signal to the optical fiber cable 101 .

In the ONU 110 that has received the second optical signal from the OLT 230, the optical/electrical converter 111 converts the second optical signal into a fourth electrical signal, and sends the fourth electrical signal to the demultiplexer 112. give. Demultiplexing section 112 separates the control frame including the MAC address from the fourth electrical signal and gives it to logical link control section 115 .

The logical link control unit 115 receives the control frame containing the MAC addresses of the logical links #2 to #4 from the demultiplexing unit 112, stores the MAC addresses “MAC#A”, “MAC#B” and “MAC# C" is stored (S65).
After storing the MAC address received from the OSU 240 in the volatile memory 118, the logical link control unit 115 notifies the OSU 240 that the MAC address has been received using an Information OAM frame (S66).

Next, the logical link control unit 115 reads the MAC addresses "MAC#A", "MAC#B" and "MAC#C" from the volatile memory 118 (S67, S68, S69).
Then, the logical link control unit 115 constructs the logical link #2 using the MAC address "MAC#A" through the MPCP Discovery sequence (S70).

In addition, the logical link control unit 115 uses the MAC address “MAC#B” to construct the logical link #3 through the MPCP Discovery sequence (S71).
Further, the logical link control unit 115 uses the MAC address "MAC#C" to construct logical link #4 through the MPCP Discovery sequence (S72).

As described above, according to Embodiment 2, since the MAC address processing unit 246 and the MAC address pool 247 are provided in the OSU 240 constituting the OLT 230, even if the number of OSUs 240 mounted in the OLT 230 increases, However, the number of MAC addresses stored in one MAC address pool 247 is a fixed number, which makes it possible to reduce the resources required for MAC address management and to more easily eliminate duplication of MAC addresses on the OSU 240 side. be able to.

In Embodiments 1 and 2, as described above, the sequence for constructing four logical links was shown, but the number of logical links is not limited to such an example.

In the first and second embodiments, when the basic logical link is no longer established, the MAC address received from the OSU 140, 240 is deleted. Examples are not limiting. For example, even if the basic logical link is no longer established, the MAC address is not erased from the volatile memory 118, and while the ONU 110 continues to be powered on, the logical link control unit 115 prevents the OSUs 140 and 240 from The received MAC address may continue to be used. MAC addresses received from OSU 140 , 240 may also be stored in non-volatile memory 117 .

Further, in Embodiments 1 and 2, the logical link control unit 115 notifies the number of logical links to the OSUs 140 and 240, but Embodiments 1 and 2 are not limited to such an example. For example, the logical link control unit 115 may notify the OSUs 140 and 240 of information that can specify the number of MAC addresses required by the ONU 110 .

Also, the MAC addresses stored in the MAC address pools 131 and 247 may be either global MAC addresses (eg, U/L bit=0) or local MAC addresses (eg, U/L bit=1). A local MAC address may be generated within the OLT 130 , 230 .

Control frames other than the Information OAM frame may be used for notification of the number of logical links from the ONU 110 and notification of MAC addresses from the OSUs 140 and 240 to the ONU 110 .

Reference Signs List 100, 200 PON system 101 optical fiber cable 102 optical splitter 110 ONU 111 photoelectric converter 112 demultiplexer 113 frame processor 114 user network I/F unit 115 logical link controller 116 storage unit , 117 nonvolatile memory, 118 volatile memory, 130 OLT, 130,230 OLT, 131 MAC address pool, 132 MAC address processing unit, 140,240 OSU, 141 photoelectric conversion unit, 142 demultiplexing unit, 143 frame processing unit, 144 Upper network I/F unit 145, 245 logical link control unit 246 MAC address processing unit 247 MAC address pool.

Claims (9)

A target slave station side which is connected to an optical fiber cable used for communicating with a plurality of slave station optical line terminating devices and which is one slave station optical line terminating device among the plurality of slave station optical line terminating devices receiving an optical signal including a first control frame including information capable of specifying the number of logical links required by the target slave station side optical line terminating equipment from the optical line terminating equipment; into an electric signal, a demultiplexing unit that separates the first control frame from the converted electric signal , and a logical link control that specifies the number of logical links from the first control frame a plurality of optical communication devices each including a section;
a storage unit that stores a plurality of MAC addresses;
based on the specified number of logical links , used in the plurality of optical communication devices except for one optical communication device connected to the target slave station side optical line terminating device among the plurality of optical communication devices The plurality of MAC addresses used in the plurality of slave station side optical line terminating devices connected to the one optical communication device, even if they overlap the MAC addresses used in the a MAC address processing unit that selects at least one MAC address from the MAC addresses,
The logical link control unit generates a second control frame including the selected at least one MAC address,
The demultiplexing unit generates an electrical signal by multiplexing the second control frame,
wherein the optical-electrical conversion unit converts the generated electrical signal into an optical signal and transmits the converted optical signal to the target slave station side optical line termination device. Device. A target slave station side which is connected to an optical fiber cable used for communicating with a plurality of slave station optical line terminating devices and which is one slave station optical line terminating device among the plurality of slave station optical line terminating devices receiving an optical signal including a first control frame including information capable of specifying the number of logical links required by the target slave station side optical line terminating equipment from the optical line terminating equipment; into an electric signal, a demultiplexing unit for separating the first control frame from the converted electric signal, a logical link control unit for specifying the number of logical links from the first control frame , a storage unit that stores a plurality of MAC addresses; a plurality of optical communication devices each including a MAC address processing unit that selects at least one MAC address from the MAC addresses of
The logical link control unit generates a second control frame including the selected at least one MAC address,
The demultiplexing unit generates an electrical signal by multiplexing the second control frame,
the optical-electrical conversion unit converts the generated electrical signal into an optical signal, and transmits the converted optical signal to the target slave station side optical network terminal ;
At least one MAC address of the plurality of MAC addresses stored in the storage unit included in one of the plurality of optical communication devices is the plurality of MAC addresses excluding the one optical communication device any one of the plurality of MAC addresses stored in the storage unit included in the optical communication device of
A master station side optical line terminal device characterized by: 3. The master station side optical line according to claim 1, wherein the plurality of MAC addresses stored in said storage unit are local MAC addresses generated in said master station side optical line terminating equipment. terminating device. The logical link control unit constructs a basic logical link, which is a logical link initially constructed with the target slave station side optical line terminating equipment via the optical/electrical conversion unit and the demultiplexing unit. , acquiring the first control frame and sending the second control frame to the target slave station side optical network terminal;
The master station side optical line termination according to any one of claims 1 to 3 , wherein the selected at least one MAC address is usable only when the basic logical link is valid. Device. A slave station side optical line terminating device that communicates with the master station side optical line terminating device via an optical fiber cable connected to the master station side optical line terminating device,
a logical link control unit for generating a first control frame including information capable of specifying the number of logical links required for communication with the master station side optical network terminal;
a demultiplexer that generates an electrical signal by multiplexing the first control frame;
an optical-electrical conversion unit that converts the generated electrical signal into an optical signal and transmits the converted optical signal to the master station side optical network terminal;
The optical-to-electrical conversion unit is connected to the master station side optical line terminating device based on the number of logical links, but the other slave station side does not share the optical fiber cable with the slave station side optical line terminating device. Even if the MAC address is duplicated with the MAC address used in the optical line terminating equipment, it is the same as the MAC address used in the other slave station side optical line terminating equipment that shares the optical fiber cable with the said slave station side optical line terminating equipment. receiving an optical signal including a second control frame including at least one MAC address selected in the master station side optical line terminating device so as not to overlap, converting the received optical signal into an electrical signal;
The demultiplexing unit demultiplexes the second control frame from the converted electrical signal,
The logical link control unit uses the at least one MAC address included in the second control frame to transmit the master station side optical network terminal via the optical/electrical conversion unit and the demultiplexing unit. and at least one logical link. 6. The local station side optical network terminal according to claim 5 , wherein said at least one MAC address is a local MAC address generated in said parent station side optical network terminal. The logical link control unit constructs a basic logical link, which is a logical link initially constructed with the master station side optical line terminating equipment via the optical/electrical conversion unit and the demultiplexing unit, Sending the first control frame to the master station side optical line terminating equipment and receiving the second control frame;
7. The local station side optical network terminal according to claim 5 , wherein said at least one MAC address is usable only when said basic logical link is valid. An optical communication system comprising a master station side optical line terminating device and a plurality of slave station side optical line terminating devices sharing one of a plurality of optical fiber cables connected to the master station side optical line terminating device and
The target slave station side optical line terminating device, which is any one of the plurality of slave station side optical line terminating devices,
a slave station side logical link control unit for generating a first control frame including information capable of specifying the number of logical links required for communication with the master station side optical network terminal;
a slave station side demultiplexing unit that generates a first electrical signal by multiplexing the first control frame;
a slave station side optical-electrical conversion unit that converts the first electrical signal into a first optical signal and transmits the first optical signal to the master station side optical network terminal;
The master station side optical line terminating equipment,
a master station side opto-electric conversion unit connected to the one optical fiber cable, receiving the first optical signal, and converting the first optical signal into a second electric signal;
a parent station side demultiplexing unit that separates the first control frame from the second electrical signal; and
a plurality of optical communication devices each including a master station side logical link control unit that specifies the number of logical links from the first control frame;
a storage unit that stores a plurality of MAC addresses;
based on the specified number of logical links , used in the plurality of optical communication devices except for one optical communication device connected to the target slave station side optical line terminating device among the plurality of optical communication devices The plurality of MAC addresses used in the plurality of slave station side optical line terminating devices connected to the one optical communication device, even if they overlap the MAC addresses used in the a MAC address processing unit that selects at least one MAC address from the MAC addresses,
The parent station side logical link control unit generates a second control frame including the selected at least one MAC address,
The master station side demultiplexing unit generates a third electrical signal by multiplexing the second control frame,
the master station side optical-electrical conversion unit converts the third electrical signal into a second optical signal, and transmits the second optical signal to the target slave station side optical line termination device;
the child station side opto-electric conversion unit receives the second optical signal, converts the second optical signal into a fourth electric signal,
the slave station side demultiplexing unit demultiplexes the second control frame from the fourth electrical signal;
Using the at least one MAC address included in the second control frame, the slave station side logical link control unit uses the slave station side opto-electric conversion unit and the slave station side demultiplexing unit to , and constructs at least one logical link with the master station side optical line terminating equipment. An optical communication system comprising a master station side optical line terminating device and a plurality of slave station side optical line terminating devices sharing one of a plurality of optical fiber cables connected to the master station side optical line terminating device and
The target slave station side optical line terminating device, which is any one of the plurality of slave station side optical line terminating devices,
a slave station side logical link control unit for generating a first control frame including information capable of specifying the number of logical links required for communication with the master station side optical network terminal;
a slave station side demultiplexing unit that generates a first electrical signal by multiplexing the first control frame;
a slave station side optical-electrical conversion unit that converts the first electrical signal into a first optical signal and transmits the first optical signal to the master station side optical network terminal;
The master station side optical line terminating equipment,
a master station optical-electrical conversion unit connected to the one optical fiber cable, receiving the first optical signal, and converting the first optical signal into a second electrical signal; a parent station side demultiplexing unit that separates the first control frame; a parent station side logical link control unit that specifies the number of logical links from the first control frame; a storage unit that stores a plurality of MAC addresses; MAC address processing for selecting at least one MAC address from the plurality of MAC addresses so as not to overlap with any of the MAC addresses used in the plurality of slave station side optical network terminals based on the number of logical links obtained comprising a plurality of optical communication devices each including a portion,
The parent station side logical link control unit generates a second control frame including the selected at least one MAC address,
The master station side demultiplexing unit generates a third electrical signal by multiplexing the second control frame,
the master station side optical-electrical conversion unit converts the third electrical signal into a second optical signal, and transmits the second optical signal to the target slave station side optical line termination device;
the child station side opto-electric conversion unit receives the second optical signal, converts the second optical signal into a fourth electric signal,
the slave station side demultiplexing unit demultiplexes the second control frame from the fourth electrical signal;
Using the at least one MAC address included in the second control frame, the slave station side logical link control unit uses the slave station side opto-electric conversion unit and the slave station side demultiplexing unit to , constructing at least one logical link with the master station side optical line terminating equipment ;
At least one MAC address of the plurality of MAC addresses stored in the storage unit included in one of the plurality of optical communication devices is the plurality of MAC addresses excluding the one optical communication device any one of the plurality of MAC addresses stored in the storage unit included in the optical communication device of
An optical communication system characterized by:

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