JP2020155888A - Subscriber line aggregation device, pon station side device, pon system and subscriber line aggregation device control method - Google Patents

Abstract

To enable an efficient utilization of downlink communication bandwidth in a PON system where communications at multiple transmission rates coexist.SOLUTION: A subscriber line aggregation device comprises: multiple transmission ports which are provided corresponding to each of multiple transmission rates for a PON system; an optical transmission part which converts downlink packets transmitted from each of the multiple transmission ports to optical signals and outputs the optical signals to a subscriber line; and a packet distribution part which selects, from the multiple transmission ports, a transmission port corresponding to a transmission rate of a multicast group to which a subscriber terminal, to which a multicast packet is to be distributed, belongs if the packet is the multicast packet, and which distributes the multicast packet so that the multicast packet is transmitted from the selected transmission port to the optical transmission port. The packet distribution part distributes the multicast packet on the basis of information related to the multicast group included in the multicast packet.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a control method for a subscriber line aggregation device, a PON station side device, a PON system, and a subscriber line aggregation device.

Japanese Unexamined Patent Publication No. 2006-352350 (Patent Document 1) discloses a PON (Passive Optical Network) system having an OLT (Optical Line Terminal) and a plurality of ONUs (Optical Network Units) connected to the OLT. In recent years, a system called virtualization OLT (virtualization PON) has been studied. In this system, the network function of the conventional OLT is managed by an external server (see, for example, Non-Patent Document 1). On the other hand, in the VDSL2 system, a configuration that replaces the conventional VDSL collecting device is being studied. For example, an SFP (Small Form Factor Pluggable) module capable of VDSL2 communication by connecting to a general-purpose switch has been developed (see, for example, Non-Patent Document 2).

Japanese Unexamined Patent Publication No. 2006-352350

Open Networking Foundation, [online], 2019, [Searched January 7, 2019], Internet <URL: https://www.opennetworking.org/voltha/> "Small Form-Factor Pluggable Long Reach Ethernet over VDSL2", [online], [Search January 7, 2019], Internet <URL: https://www.comnet.net/comnet-products/accessories/sfp-vdsl >

Even in the virtualized PON as disclosed in Non-Patent Document 1, it is conceivable to make the OLT hardware smaller than before. However, by reducing the size of the OLT, the parts mounted on the OLT can also be limited. Therefore, in the case of a miniaturized OLT, it is assumed that its function is limited. On the other hand, the function of aggregating subscriber lines is necessary for OLT. Therefore, in the miniaturized OLT, the function related to communication with the higher-level device may be limited as compared with the conventional OLT. However, none of the above documents disclose that a single transceiver module supports both 1G-EPON and 10G-EPON.

When both 1G-EPON and 10G-EPON are supported by one transceiver module, control of the transceiver module is required to efficiently use the downlink communication band. For example, even though only communication for 1G-EPON is required, if both communication for 1G-EPON and communication for 10G-EPON are performed, the communication band between the transceiver module and the ONU will be longer than necessary. May be consumed.

Therefore, an object of the present disclosure is to enable efficient use of the downlink communication band in a PON system in which communication at a plurality of transmission speeds coexists.

The subscriber line aggregating device of the present disclosure is a subscriber line aggregating device for a PON system configured to be detachably attached to and detachable from a relay device for relaying IP packets, and is used for a plurality of transmission speeds of the PON system. Correspondingly provided multiple transmission ports and an optical transmitter that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to the subscriber line, and packets. When is a multicast packet, a transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from a plurality of transmission ports, and optical transmission is performed from the selected transmission port. It is equipped with a packet distribution unit that distributes multicast packets so that multicast packets are sent to the unit, and the packet distribution unit distributes multicast packets based on information about the multicast group included in the multicast packet. It is an integrated device.

The PON station side device of the present disclosure includes a relay device for relaying an IP packet and a subscriber line aggregation device configured to be detachable from the relay device, and the subscriber line aggregation device has a plurality of transmission speeds. A plurality of transmission ports provided corresponding to each, an optical transmission unit that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to the subscriber line. When the packet is a multicast packet, the transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from a plurality of transmission ports, and optical from the selected transmission port. It is provided with a packet distribution unit that distributes multicast packets so that multicast packets are sent to the transmission unit, and the packet distribution unit distributes multicast packets based on information about the multicast group included in the multicast packets. It is a side device.

The PON system of the present disclosure includes a relay device for relaying an IP packet, a subscriber line aggregation device configured to be detachably attached to the relay device, and a plurality of subscriber terminals corresponding to a plurality of transmission speeds. , The subscriber line aggregation device converts the downlink packets sent from the plurality of transmission ports and the plurality of transmission ports, which are provided corresponding to the plurality of transmission speeds, into optical signals to obtain optical signals. The subscriber line aggregating device includes an optical transmitter that outputs a signal to the subscriber line, and when the downlink packet is a multicast packet, the transmission of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs. This is a PON system that selects a transmission port corresponding to a speed from a plurality of transmission ports and distributes the multicast packet so that the multicast packet is sent from the selected transmission port to the optical transmission unit.

In the control method of the subscriber line aggregating device configured to be detachably attached to the relay device for relaying the IP packet of the present disclosure, the subscriber line aggregating device is provided corresponding to a plurality of transmission speeds. The control method includes the transmission port of the above and an optical transmitter that converts the downlink packet sent from each of the plurality of transmission ports into an optical signal and outputs the optical signal to the subscriber line. In the case of a packet, the step of selecting a transmission port corresponding to the transmission speed of the group of subscriber terminals to which the multicast packet should be delivered from a plurality of transmission ports based on the information about the multicast group contained in the multicast packet. This is a control method for a subscriber line aggregation device, which includes a step of distributing a multicast packet so that a multicast packet is sent from a transmission port selected in the selection step to an optical transmission unit.

According to the present disclosure, in a PON system in which communication at a plurality of transmission speeds coexists, it is possible to efficiently use the communication band in the downlink direction.

FIG. 1 is a schematic configuration diagram of a PON system according to an embodiment of the present disclosure. FIG. 2 is a block diagram showing a schematic configuration of the subscriber line aggregation device shown in FIG. FIG. 3 is a diagram for explaining transmission of a multicast packet assumed when the data distribution according to the embodiment of the present disclosure is omitted. FIG. 4 is a sequence diagram showing an example of the setting flow of the relay device and the subscriber line aggregation device for multicast communication. FIG. 5 is a diagram showing an example of the configuration of the table registered in the management device. FIG. 6 is a diagram illustrating packet processing by the relay device and the subscriber line aggregation device. FIG. 7 is a sequence diagram showing another example of the setting flow of the relay device and the subscriber line aggregation device for multicast communication.

[Explanation of Embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described.

(1) The subscriber line aggregating device of the present disclosure is a subscriber line aggregating device for a PON system configured to be detachably attached to a relay device for relaying IP packets, and is a plurality of transmissions of the PON system. An optical transmitter that converts downlink packets sent from a plurality of transmission ports and each of the plurality of transmission ports, which are provided corresponding to each speed, into optical signals and outputs the optical signals to the subscriber line. And, when the packet is a multicast packet, the transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from a plurality of transmission ports, and the selected transmission port is selected. It is provided with a packet distribution unit that distributes multicast packets so that multicast packets are sent from to the optical transmission unit, and the packet distribution unit distributes multicast packets based on information about the multicast group included in the multicast packets. It is a subscriber line aggregation device.

According to the above, in a PON system in which communication at a plurality of transmission speeds coexists, it is possible to efficiently use the communication band in the downlink direction. If the subscriber line aggregating device cannot distribute the multicast packet, it is necessary to send the multicast packet from each of the multiple transmission ports to the optical transmitter in consideration of communication at any of the multiple transmission speeds. .. However, in this case, the downlink communication band is consumed more than necessary. Select the transmission port corresponding to the transmission speed of the subscriber terminal to which the multicast packet should be delivered from multiple transmission ports. The multicast packet is distributed so that the multicast packet is sent from the selected transmission port to the optical transmitter. Therefore, it is possible to efficiently use the communication band in the downlink direction.

(2) Preferably, the information about the multicast group is a VLAN ID.
According to the above, the packet distribution unit can identify the transmission port corresponding to the transmission speed of the subscriber terminal to which the multicast packet should be delivered.

(3) Preferably, the packet distribution unit distributes the multicast packet by collating the VLAN ID included in the multicast packet with the VLAN ID notified from the management device.

According to the above, the management device sets the VLAN ID, and the subscriber line aggregation device takes over the information related to the setting. There is no need for the subscriber line aggregation device to set a VLAN ID. Therefore, the function of the subscriber line aggregation device can be simplified.

(4) Preferably, when the packet distribution unit receives the request packet requesting the multicast communication from the subscriber terminal, the packet distribution unit requests the management device to set the VLAN ID.

According to the above, the VLAN ID can be set by triggering the reception of the request packet by the subscriber line aggregation device.

(5) Preferably, when the packet distribution unit detects the link-up of the subscriber terminal, it requests the management device to set the VLAN ID.

According to the above, the VLAN ID can be set by triggering the link-up of the subscriber terminal.

(6) The PON station side device of the present disclosure includes a relay device for relaying an IP packet and a subscriber line aggregation device configured to be detachable from the relay device, and the subscriber line aggregation device includes a plurality of subscriber line aggregation devices. Optical transmission that converts downlink packets sent from a plurality of transmission ports and each of the plurality of transmission ports, which are provided corresponding to each transmission speed, into optical signals and outputs the optical signals to the subscriber line. When the packet is a multicast packet, the transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from a plurality of transmission ports, and the selected transmission is performed. It is provided with a packet distribution unit that distributes multicast packets so that multicast packets are sent from a port to an optical transmission unit, and the packet distribution unit distributes multicast packets based on information about the multicast group included in the multicast packets. , PON station side device.

According to the above, in a PON system in which communication at a plurality of transmission speeds coexists, it is possible to efficiently use the communication band in the downlink direction.

(7) The PON system of the present disclosure includes a relay device for relaying IP packets, a subscriber line aggregation device configured to be detachable from the relay device, and a plurality of subscriber terminals corresponding to a plurality of transmission speeds. The subscriber line aggregating device converts a plurality of transmission ports and downlink packets sent from each of the plurality of transmission ports, which are provided corresponding to a plurality of transmission speeds, into optical signals. Including an optical transmitter that outputs an optical signal to the subscriber line, the subscriber line aggregation device uses the multicast to which the subscriber terminal to which the multicast packet should be delivered belongs when the downlink packet is a multicast packet. This is a PON system that selects a transmission port corresponding to the transmission speed of a group from a plurality of transmission ports and distributes the multicast packet so that the multicast packet is sent from the selected transmission port to the optical transmission unit.

According to the above, in a PON system in which communication at a plurality of transmission speeds coexists, it is possible to efficiently use the communication band in the downlink direction.

(8) In the control method of the subscriber line aggregating device configured to be detachably attached to the relay device for relaying the IP packet of the present disclosure, the subscriber line aggregating device is provided corresponding to each of a plurality of transmission speeds. In addition, the control method includes a plurality of transmission ports and an optical transmission unit that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to the subscriber line. When the packet is a multicast packet, the transmission port corresponding to the transmission speed of the group of subscriber terminals to which the multicast packet should be delivered is selected from multiple transmission ports based on the information about the multicast group contained in the multicast packet. It is a control method of a subscriber line aggregation device including a step of selecting and a step of distributing a multicast packet so that a multicast packet is sent from a transmission port selected in the selection step to an optical transmission unit.

According to the above, in a PON system in which communication at a plurality of transmission speeds coexists, it is possible to efficiently use the communication band in the downlink direction.

[Details of Embodiments of the present disclosure]
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a schematic configuration diagram of a PON system according to an embodiment of the present disclosure. The PON system 100 includes a management server 1, a network 2, an OLT 3 which is a PON station side device, one or more ONUs (subscriber terminal devices), and a subscriber line 5. FIG. 1 illustrates four ONUs (ONU4A, 4B, 4C, 4D). The number of ONUs is not particularly limited.

The management server 1 and the distribution server 8 are connected to the network 2. The management server 1 is a management device that manages the PON system 100. The distribution server 8 is a server for distributing content.

The PON station side device 3 includes a relay device 11 and a subscriber line aggregation device 12. The relay device 11 is a device for relaying IP packets and is connected to the network 2. The relay device 11 can be realized by a general-purpose relay device. For example, a general-purpose Ethernet (registered trademark) switch can be applied to the relay device 11.

The subscriber line aggregating device 12 has a function of aggregating subscriber lines. The subscriber line aggregation device 12 is connected to the port 13 of the relay device 11 and can be attached to and detached from the relay device 11. The shape of the subscriber line aggregation device 12 can be any shape that allows the subscriber line aggregation device 12 to be attached to and detached from the port 13. The shape of the subscriber line aggregation device 12 can be determined according to the standard of the port 13. In one example, the shape of the subscriber line aggregation device 12 may be a shape that conforms to SFP +.

Each of ONU4A, 4B, 4C, and 4D is an optical line termination device installed on the subscriber side. The ONUs 4A, 4B, 4C, and 4D are connected to the subscriber line aggregation device 12 by the subscriber lines 5A, 5B, and 5C, respectively.

In the example shown in FIG. 1, the home gateway (HGW) is connected to the ONU on the subscriber side (home gateways 6A, 6B, 6C, 6D). The home gateway can have a router function. The user terminal is connected to the home gateway by wire or wirelessly (user terminals 7A, 7B, 7C, 7D). The type and number of user terminals are not particularly limited.

According to the present disclosure, the PON system 100 is configured to enable communication at a plurality of transmission speeds (bit rates). In one example, the PON system 100 is a system in which 1G-EPON (GE-PON) and 10G-EPON coexist. Therefore, the OLT 3 can communicate with each of the 1G-EPON ONU and the 10G-EPON ONU. In the example shown in FIG. 1, ONU4A and ONU4B are ONUs for 1G-EPON, and ONU4C and ONU4D are ONUs for 10G-EPON.

The management server 1 has a subscriber line management unit 21. The subscriber line management unit 21 manages and controls the subscriber lines aggregated by the subscriber line aggregation device 12. The subscriber line management unit 21 is realized by the arithmetic unit of the management server 1 executing the software module. Therefore, the subscriber line aggregation device 12 does not have to have the function of managing the subscriber line.

The PON system shown in FIG. 1 is capable of unicast communication, broadcast communication, and multicast communication. Multicast communication is to transmit data to a plurality of specific terminals (nodes) at the same time.

For example, a request packet for multicast communication (not shown in FIG. 1) is transmitted from ONU4A, which is an ONU for 1G-EPON. In response to the request packet, a downlink multicast packet is transmitted from OLT3. In this case, the OLT 3 transmits a multicast packet for 1G-EPON. In multicast communication, only the ONU that transmitted the request packet for multicast communication communicates. Therefore, only ONU4A communicates data. The ONU4B is the same ONU for 1G-EPON as the ONU4A. When ONU4B does not participate in the same multicast group as ONU4A, ONU4B receives the multicast packet from OLT3, but discards the packet.

FIG. 2 is a block diagram showing a schematic configuration of the subscriber line aggregation device 12 shown in FIG. The subscriber line aggregation device 12 includes a data receiving unit 31, a data transmitting unit 32, a processing circuit 33, an optical transmitting unit 34, and an optical receiving unit 35. The processing circuit 33 includes a packet distribution unit 40, a 10G transmission port 41, a 1G transmission port 42, and a reception port 43. The processing circuit 33 is realized by, for example, a semiconductor integrated circuit.

When the downlink data is a multicast packet, the packet distribution unit 40 sets the transmission port corresponding to the transmission speed of the group of subscriber terminals to which the multicast packet should be delivered of the 10G transmission port 41 and the 1G transmission port 42. Select from. The packet distribution unit 40 distributes the multicast packet so that the multicast packet is sent from the selected transmission port to the optical transmission unit 34.

When executing the above-mentioned multicast communication, the downlink multicast packet sent from the relay device 11 includes a VLAN (Virtual Local Area Network) ID. The VLAN ID corresponds to information about the multicast group. In this disclosure, different VLAN IDs are assigned to the 1G-EPON communication and the 10G-EPON communication. The packet distribution unit 40 receives a downlink multicast packet from the relay device 11 via the data reception unit 31. The packet distribution unit 40 can determine whether the transmission of the multicast packet is the communication for 10G-EPON or the communication for 1G-EPON based on the VLAN ID.

Further, the packet distribution unit 40 sets a logical link based on the VLAN ID included in the multicast packet, and sets an LLID (Logical Link ID) for identifying the logical link. For this purpose, the packet distribution unit 40 includes a VLAN-LLID setting unit 45 and a VLAN-LLID setting information storage unit 46. The VLAN-LLID setting unit 45 identifies the LLID from the VLAN ID based on the information stored in the VLAN-LLID setting information storage unit 46. The VLAN-LLID setting information storage unit 46 stores information in which the VLAN ID and the LLID are associated with each other.

When the transmission of the multicast packet is communication for 10G-EPON, the packet distribution unit 40 distributes the multicast packet to the 10G transmission port 41. On the other hand, when the transmission of the multicast packet is the communication for 1G-EPON, the packet distribution unit 40 distributes the multicast packet to the 1G transmission port 42.

The optical transmission unit 34 generates an optical signal for transmitting a downlink packet to the ONU, and transmits the optical signal to the ONU through the subscriber line 5. In this embodiment, the optical transmission unit 34 is a 10G optical transmission unit 51 that transmits an optical signal for communication for 10G-EPON and a 1G optical transmission unit that transmits an optical signal for communication for 1G-EPON. Including 52 and.

On the other hand, the ONU transmits an upstream packet in the form of an optical signal. The optical receiving unit 35 receives an optical signal from the ONU and converts the optical signal into an electric signal. The packet distribution unit 40 receives an uplink packet via the reception port 43 and sends the packet to the data transmission unit 32.

FIG. 3 is a diagram for explaining transmission of a multicast packet assumed when the data distribution according to the embodiment of the present disclosure is omitted. For example, suppose that an ONU for 1G-EPON (may be a multicast group consisting of an ONU for 1G-EPON) requests reception of a multicast packet. Although the subscriber line aggregation device 12 receives the multicast packet from the host system, it cannot distribute the multicast packet to the 1G-EPON ONU that requests the multicast packet. Even when the 10G-EPON ONU requests the reception of the multicast packet, the subscriber line aggregation device 12 cannot distribute the downlink multicast packet to the 10G-EPON ONU requesting the multicast packet.

In order to solve such a problem, it is conceivable to send a multicast packet to both the 10G transmission port 41 and the 1G transmission port 42 as shown in FIG. In this case, the ONU requesting the multicast packet can receive the packet. On the other hand, the optical transmission unit 34 generates an optical signal for communication for 1G-EPON and an optical signal for communication for 10G-EPON. Therefore, unnecessary communication also occurs. In other words, there arises a problem that the communication band between the subscriber line aggregation device 12 and the ONU is consumed more than necessary.

In the embodiment of the present disclosure, the VLAN-LLID setting unit 45 should send the multicast packet to either the 1G-EPON ONU or the 10G-EPON ONU based on the VLAN ID assigned to the multicast packet. Determine if it is a packet. Based on the determination result, the multicast packet is distributed to either the 10G transmission port 41 or the 1G transmission port 42. This makes it possible to efficiently use the downlink communication band in a PON system in which communication at a plurality of transmission speeds coexists.

In order to execute the distribution of the multicast packet as described above, it is necessary to set the VLAN ID for 1G-EPON and the VLAN ID for 10G-EPON. Further, it is necessary to match the setting contents related to the VLAN ID between the relay device 11 and the subscriber line aggregation device 12.

FIG. 4 is a sequence diagram showing an example of the setting flow of the relay device 11 and the subscriber line aggregation device 12 for multicast communication. As shown in FIG. 4, for example, a request packet for multicast communication is transmitted from an ONU for 1G-EPON (for example, ONU4A) (step S1).

The subscriber line aggregation device 12 receives the request packet and transmits the information contained in the packet to the management server 1 (management device) (step S2).

The management server 1 determines the VLAN ID to be assigned to the subscriber line aggregation device 12 and the relay device 11, and registers the VLAN ID in the table. Then, the VLAN ID is set in each device. As a result, the VLAN ID of the 1G-EPON ONU (for example, ONU4A) is set in the relay device 11 and the subscriber line aggregation device 12 (step S3). In the example shown in FIG. 4, the VLAN ID can be set by triggering that the subscriber line aggregation device 12 receives the request packet. Since the subscriber line aggregation device 12 inherits the information of the VLAN ID set by the management server 1, it is not necessary to set the VLAN ID. Therefore, the function of the subscriber line aggregation device 12 can be simplified.

When the settings of the relay device 11 and the subscriber line aggregation device 12 are completed, the communication of multicast communication between the ONU that transmitted the request packet and the OLT 3 (relay device 11 and the subscriber line aggregation device 12) starts (step). S4).

FIG. 5 is a diagram showing an example of the configuration of the table registered in the management device. In the table shown in FIG. 5, the notation "communication device" represents a relay device, and the notation "line aggregation device" represents a subscriber line aggregation device. As shown in FIG. 5, a plurality of subscriber line aggregation devices may be connected to one relay device. The management device can also manage a plurality of relay devices. Therefore, in the example shown in FIG. 5, a VLAN ID for 1G-EPON and a VLAN ID for 10G-EPON are set for each subscriber line aggregation device managed by the management device.

FIG. 6 is a diagram illustrating packet processing by the relay device and the subscriber line aggregation device. Packets sent from the distribution server are data, a source IP address for identifying the source distribution server, and a group IP address for identifying the multicast group to receive the data (source IP address). Includes a Group IP Address) and a MAC (Media Access Control) header containing a multicast MAC (Media Access Control) address. Depending on the network configuration between the distribution server and the relay device, a VLAN ID different from the VLAN ID set by the management device may be stored in the packet.

When the relay device 11 receives the packet from the distribution server, the relay device 11 assigns the VLAN ID to the packet. With reference to FIG. 5, for example, the relay device 11 corresponds to the “communication device 1”, the subscriber line aggregation device 12 corresponds to the “line aggregation device 1”, and the packet is an ONU for 1G-EPON (for example, ONU4A). In the case of a packet for, the VLAN ID is "vlan100". Therefore, the relay device 11 adds "vlan100" as a VLAN ID to the packet, and sends the packet to the subscriber line aggregation device 12.

The subscriber line aggregation device 12 (packet distribution unit 40) receives the packet from the relay device 11 and collates the VLAN ID notified from the management server 1 with the VLAN ID included in the packet. The packet distribution unit 40 distributes packets based on the collation result. The subscriber line aggregation device 12 sends a packet to the destination 1G-EPON ONU (ONU4A). When transmitting the packet to the ONU, the subscriber line aggregation device 12 may delete the VLAN ID from the packet. Alternatively, the VLAN ID may be deleted in the ONU4A after the ONU4A receives the packet.

FIG. 7 is a sequence diagram showing another example of the setting flow of the relay device 11 and the subscriber line aggregation device 12 for multicast communication. In the example shown in FIG. 7, the setting is executed when the ONU is linked up.

First, a certain ONU (for example, ONU4A) links up (step S11). ONU link-up can be performed according to the general link-up procedure in EPON. When the ONU links up, the subscriber line aggregation device 12 transmits the link-up information to the management device (step S12).

The management server 1 determines the VLAN ID to be assigned to the ONU, and registers the VLAN ID in the table. Then, the VLAN ID is set in the relay device 11 and the subscriber line aggregation device 12 (step S13). The process of step S13 is the same as the process of step S3 shown in FIG.

After the setting is completed, the ONU transmits a request packet for multicast communication (step S14). Multicast communication communication is started between the ONU that transmitted the request packet and the OLT 3 (relay device 11 and subscriber line aggregation device 12) (step S15).

According to the embodiments of the present disclosure, the OLT includes a relay device and a subscriber line aggregation device that can be attached to and detached from the relay device. The relay device is a general-purpose communication device. By downsizing / labor-saving the subscriber line aggregating device, the parts mounted on the subscriber line aggregating device can be limited.

In the PON system, the optical transmitter and the optical receiver need to be provided in the subscriber line aggregation device. Therefore, in the miniaturized subscriber line aggregation device, the function related to communication with the host device may be limited. However, as shown in FIG. 3, when the multicast packet cannot be distributed, the downlink communication band is consumed more than necessary. According to the embodiment of the present disclosure, a transmission port corresponding to the transmission speed of the subscriber terminal to which the multicast packet should be delivered is selected from a plurality of transmission ports. The multicast packet is distributed so that the multicast packet is sent from the selected transmission port to the optical transmitter. Therefore, according to the embodiment of the present disclosure, it is possible to efficiently use the downlink communication band when performing multicast communication in a PON system capable of supporting a plurality of transmission speeds.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims rather than the embodiments described above, and is intended to include meaning equivalent to the scope of claims and all modifications within the scope.

1 Management server 2 Network 3 OLT (PON station side device)
4A, 4B, 4C, 4D ONU (subscriber terminal device)
5,5A, 5B, 5C Subscriber line 6A, 6B, 6C, 6D Home gateway 7A, 7B, 7C, 7D User terminal 8 Distribution server 11 Relay device 12 Subscriber line Aggregation device 13 Port 21 Subscriber line management unit 31 Data Reception unit 32 Data transmission unit 33 Processing circuit 34 Optical transmission unit 35 Optical reception unit 40 Packet distribution unit 41 10G transmission port 42 1G transmission port 43 Reception port 45 VLAN-LLID setting unit 46 VLAN-LLID setting information storage unit 51 10G optical Transmitter 52 1G Optical Transmitter 100 PON System S1, S2, S3, S4, S11, S12, S13, S14, S15 Steps

Claims (8)

It is a subscriber line aggregation device for a PON system that is detachably configured to and from a relay device for relaying IP packets.
A plurality of transmission ports provided corresponding to a plurality of transmission speeds of the PON system, and
An optical transmitter that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to a subscriber line.
When the packet is a multicast packet, a transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from the plurality of transmission ports, and the selected transmission is selected. A packet distribution unit for distributing the multicast packet is provided so that the multicast packet is sent from the port to the optical transmission unit.
The packet distribution unit is a subscriber line aggregation device that distributes the multicast packet based on the information about the multicast group included in the multicast packet. The subscriber line aggregation device according to claim 1, wherein the information regarding the multicast group is a VLAN ID. The packet distribution unit
The subscriber line aggregation device according to claim 2, wherein the multicast packet is distributed by collating the VLAN ID included in the multicast packet with the VLAN ID notified from the management device. The subscriber line aggregation device according to claim 3, wherein when the packet distribution unit receives a request packet requesting multicast communication from the subscriber terminal, it requests the management device to set the VLAN ID. The subscriber line aggregation device according to claim 3, wherein when the packet distribution unit detects a link-up of the subscriber terminal, the management device is requested to set the VLAN ID. It is a PON station side device,
A relay device for relaying IP packets and
The relay device is provided with a detachable subscriber line aggregation device.
The subscriber line aggregation device is
Multiple transmission ports provided for each of multiple transmission speeds,
An optical transmitter that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to a subscriber line.
When the packet is a multicast packet, a transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs is selected from the plurality of transmission ports, and the selected transmission is selected. A packet distribution unit for distributing the multicast packet is provided so that the multicast packet is sent from the port to the optical transmission unit.
The packet distribution unit is a PON station side device that distributes the multicast packet based on the information about the multicast group included in the multicast packet. It is a PON system
A relay device for relaying IP packets and
A subscriber line aggregation device that is detachably configured to and from the relay device,
Equipped with multiple subscriber terminals that support multiple transmission speeds,
The subscriber line aggregation device is
Multiple transmission ports provided for each of multiple transmission speeds,
It includes an optical transmission unit that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to a subscriber line.
When the downlink packet is a multicast packet, the subscriber line aggregating device sets a transmission port corresponding to the transmission speed of the multicast group to which the subscriber terminal to which the multicast packet should be delivered belongs from a plurality of transmission ports. A PON system that selects and distributes the multicast packet so that the multicast packet is sent from the selected transmission port to the optical transmitter. It is a control method of a subscriber line aggregation device that is detachably configured to be attached to and detachable from a relay device for relaying an IP packet.
Multiple transmission ports provided for each of multiple transmission speeds,
It includes an optical transmission unit that converts downlink packets sent from each of the plurality of transmission ports into optical signals and outputs the optical signals to a subscriber line.
The control method is
When the packet is a multicast packet, the plurality of transmission ports corresponding to the transmission speed of the group of subscriber terminals to which the multicast packet should be delivered are provided based on the information about the multicast group included in the multicast packet. Steps to select from the sending ports of
A control method for a subscriber line aggregation device, comprising a step of distributing the multicast packet so that the multicast packet is sent from the transmission port selected in the selection step to the optical transmission unit.

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