JP2009239785A - Communication device and repeater device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device can arbitrate to prevent two input packets from colliding with each other. <P>SOLUTION: A packet includes information about priority in a header part. There are provided first and second classification means for classifying packets from first and second input parts into a plurality of classes in accordance with the information about priority, and first and second buffer parts that sequentially hold the packets from the first and second input parts for each class classified by the first and second classification means. There is also provided a communication arbitration means that, when the class classified by the first classification means is the same as that classified by the second classification means, gives priority to the packets buffered in the first buffer and the second buffer on the assumption that the priority of the first buffer and the second buffer is observed, and reads the packets from the first buffer part and the second buffer part sequentially in order of decreasing priority, and sends them out as an output. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication apparatus and a relay apparatus suitable for use in a communication path using, for example, a PPPoE (Point to Point Protocol over Ethernet (registered trademark)) protocol.

  FIG. 19 shows an outline of a configuration of an example of a communication system using the PPPoE protocol.

  As shown in FIG. 19, a server of a broadband service provider 2 is connected to the Internet 1. Communication equipment in homes or offices is connected to a broadband connection provider 2 through an optical cable or an ADSL (Asymmetric Digital Subscriber Line) 3, and is connected to the Internet 1 through the broadband connection provider 2.

  At home or business, an optical cable or ADSL 3 is connected to a router 5 through a broadband modem / line terminator 4. A plurality of personal computers 6 and game machines 7 are connected to the router 5 through a LAN (Local Area Network) made of, for example, Ethernet (registered trademark).

  In the system configuration of FIG. 19, if the router 5 has a PPPoE function, a plurality of personal computers 6 can directly access the Internet 1. The PPPoE client in that case is the router 5. In this case, the broadband modem / line terminating device 4 includes a relay device called a PPPoE bridge.

  If the game machine 7 has a PPPoE function, the game machine 7 can transfer PPPoE packets through the PPPoE bridge of the broadband modem / line terminator 4 without going through the router 5.

  The sequence in PPPoE in this communication system is as shown in FIG. 20, for example, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2003-333064). Also, the format of the PPPoE frame is as shown in FIG. First, the format of the PPPoE frame in FIG. 21 will be described.

  As shown in FIG. 21, the PPPoE frame is composed of a destination address “DESTINATION_ADDR”, a transmission source address “SOURCE_ADDR”, a packet type “ETHER_TYPE”, data “payload”, and a checksum “CHECKSUM” for error detection. The destination address “DESTINATION_ADDR”, the source address “SOURCE_ADDR”, and the packet type “ETHER_TYPE” are header parts of the PPPoE frame.

  The packet type “ETHER_TYPE” is discrimination information for discriminating between a management packet and a data communication packet. Specifically, when the packet type “ETHER_TYPE” is “0x8863”, this indicates that the packet is a management packet (Discovery Stage (at the start of a PPPoE session)), and “0x8864”. In some cases, the packet indicates a data communication packet (PPP Session Stage (during PPP communication)).

  Accordingly, by identifying which of the above packet types “ETHER_TYPE” is, it is possible to determine whether the packet is a management packet or a data communication packet.

  The data “payload” includes the version “VER”, the type “TYPE”, the code “CODE” indicating the session state of the packet, the session identification information of PPPoE (session ID (Identification)) “SESSION_ID”, and the payload It consists of a header portion consisting of length information “LENGTH” and a payload “payload” as a data portion.

  The session ID is transmission path identification information for identifying a packet transmission path connected between two points to start communication. Here, the session means a virtual transmission path.

  The code “CODE” indicates the status of five sessions as shown in FIG. That is, “CODE” includes PADI (PPPoE Active Discovery Initiation), PADO (PPPoE Active Discovery Over), PADR (PPPoE Active Discovery Request), and PADS (CPPE). (Terminate) and any one of the five types of code information.

  Next, a communication sequence in PPPoE will be described with reference to FIG. In FIG. 20, the PPPoE client is the router of FIG. The PPPoE server is a server of the broadband service provider 2.

  (1) First, the PPPoE client broadcasts a packet for searching for a PPPoE server (“CODE” is a PADI packet; hereinafter referred to as a PADI packet).

  (2) The PPPoE server returns a reply packet ("CODE" is a PADO packet; hereinafter referred to as a PADO packet) to the PPPoE client.

  (3) Since the PPPoE client can specify the PPPoE server by the PADO packet of this response, a packet requesting the session start of the specified PPPoE server (“CODE” is a PADR packet; hereinafter referred to as a PADR packet) Send.

  (4) Upon receiving this PADR packet, the PPPoE server sets a session ID for the transmission path on which communication is to be started, and a packet for notifying the session ID including the session ID (“CODE” is PADS). (Hereinafter referred to as PADS packet) to the PPPoE client.

  Through the above sequence (1) to (4) (PPPoE session stage), the PPPoE server specifies the destination address “DESTATION_ADDR” of the PPPoE client that establishes the session, and sets the session ID and the PPPoE of the session ID. Notify the client terminal.

  Following the PPPoE session stage, a PPP session stage sequence is performed.

  (5) First, negotiation is performed by LCP (Link Control Protocol) to establish a data link (packet transmission path).

  (6) Next, authentication is performed.

  (7) Next, PPP negotiation is started, and global IP addresses on the Internet 1 are assigned by IPCP (Internet Protocol Control Protocol) negotiation.

  (8) Then, communication by PPP is started.

  Management packets are exchanged between the PPPoE client and the PPPoE server in the above-described PPPoE session stage (1) to (4), and in the subsequent PPP session stage (5) to (8). Packets for data communication are exchanged.

  The PPPoE bridge of the broadband modem / line terminator 4 described above is provided between a PPPoE client and a PPPoE server, as shown in FIG. 20, and relays packets between them.

  Incidentally, as shown in FIG. 22, the conventional PPPoE bridge 10 includes a WAN (Wide Area Network) side interface 11, a LAN side interface 12, and a bridge unit 13.

  In the case of the example of FIG. 19, the WAN side interface 11 is an interface connected to the Internet side, and the LAN side interface 12 is an interface connected to the router 5.

  The bridge unit 13 is configured by a microcomputer (CPU), a DSP (Digital Signal Processor), and the like. The software side processes the management packet and the data communication packet without distinguishing between them, and the WAN side. From the interface 11 to the LAN side interface 12 or vice versa, relay transfer is performed as shown by a dotted arrow in FIG.

The above-mentioned patent documents are as follows.
JP 2003-333064 A

  As shown in FIG. 21, in the conventional PPPoE bridge 10, the management unit and the data communication packet are all handled by software in the bridge unit 13. For this reason, when the number of sessions increases, the performance of the microcomputer constituting the bridge unit 10 may become a problem.

  In some cases, the PPPoE bridge 10 needs to perform session management. For example, the software program of the bridge unit 13 of the PPPoE bridge 10 is downloaded by accessing a server connected to the Internet and updated.

  In such a case, the bridge unit 13 of the PPPoE bridge 10 needs to manage the session and perform its own PPPoE communication. In the conventional case, this session management needs to be performed by the bridge unit 13. However, since the bridge unit 13 handles both the management packet and the data communication packet, the load on the bridge unit 13 is reduced. Weighting can cause problems in its performance.

  Therefore, the applicant has devised a new relay device that solves the above problems. FIG. 23 is a block diagram showing an outline of the configuration of the PPPoE bridge 20 as an example of a new relay device devised by the applicant.

  As shown in FIG. 23, the PPPoE bridge 20 of this example includes a WAN side interface 21 and a LAN side interface 22 similar to the WAN side interface 11 and the LAN side interface 12 of the PPPoE bridge unit 10 of the conventional example described above.

  In the PPPoE bridge 20 of this example, the bridge unit 10 of the PPPoE bridge unit 10 of the conventional example described above is divided into a management packet bridge unit 23 and a data packet bridge unit 24, and the management packet bridge unit 23 is divided. Is configured to be connected to the WAN side interface 21 and the LAN side interface 22 via the data packet bridge unit 24.

  The data packet bridge unit 24 has a function of determining whether a PPPoE packet coming from the WAN side interface 21 or the LAN side interface 22 is a management packet or a data communication packet.

  When the data packet bridge unit 24 determines that the PPPoE packet coming from the WAN side interface 21 or the LAN side interface 22 is a management packet, the data packet bridge unit 24 passes the management packet to the management packet bridge unit 23. To.

  When the data packet bridge unit 24 determines that the PPPoE packet arriving from the WAN side interface 21 or the LAN side interface 22 is a data communication packet, the data communication packet is transmitted to the management packet bridge unit 23. Instead of passing through, the inside of the bridge unit 24 is made transparent (transfer relay).

  That is, in the PPPoE bridge 20 of this example, the management packet bridge unit 23 is configured to handle only the management packet and the data communication packet is transmitted only through the data packet bridge unit 24.

  That is, as shown by a thick dotted line 25 in FIG. 23, the management packet is relayed between the WAN side interface 21 and the LAN side interface 22 (hereinafter referred to as the WAN side interface 21) by the management packet bridge unit 23. Relay transfer with the LAN side interface 22 is called bridge transfer). The data communication packet is bridge-transferred by the data packet bridge unit 24 as indicated by a thin dotted line 26 in FIG.

  As a result, in the PPPoE bridge 20 of this example, the management packet bridge unit 23 executes the bridge transfer of the management packet in the PPPoE session sequence shown in the PPPoE sequence in FIG. 23, and the PPP after the session is established. The bridge transfer of the data communication packet in the session is performed only through the data packet bridge unit 24.

  Therefore, the management packet bridge unit 23 includes a microcomputer (CPU) and has a software processing configuration. Since the management packet bridge unit 23 only needs to handle the management packet, the burden of the software processing is reduced and the performance is improved. Also, session management by the management packet bridge unit 23 is facilitated.

  The data packet bridge unit 24 can have a hardware processing configuration using, for example, an FPGA (Field Programmable Gate Array) and the like, and bridge transfer of packets for data communication can be performed at high speed at a so-called wire speed. . In addition, in this case, the data packet bridge unit 24 has an advantage that it is not necessary to consider the performance of the management packet bridge unit 23.

  By the way, with the configuration shown in FIG. 23, the management packet bridge unit 23 can easily manage a session by software processing. When a packet of an unknown session is received, Processing such as discarding and disconnecting the session can be performed.

  In addition, for example, the software program of the management packet bridge unit 23 can be updated to a new one, so that the relay device can be operated as a PPPoE client. In this case, if there is no free session, the session is disconnected. You can also perform processing such as creating a vacancy.

  In such a case, a connection management packet is transmitted from the management packet bridge unit 23 at an arbitrary timing regardless of the packet from the LAN side or the WAN side. However, the data packet bridge unit 24 does not manage the transmission timing of the management packet from the management packet bridge unit 23.

  Therefore, as is apparent from FIG. 23, the data packet bridge unit 24 bridges the data communication packet from the LAN side to the WAN side. Conversely, the data packet bridge unit 24 transmits the data communication packet from the WAN side to the LAN. In the case of the bridge transfer to the side, there is a high possibility that a collision with the management packet from the management packet bridge unit 23 occurs and any packet is discarded.

  Such a collision between two input packets is a problem that occurs not only in the above-described relay apparatus but also in other communication apparatuses that perform packet communication.

  In view of the above problems, an object of the present invention is to perform arbitration so that a collision between two input packets does not occur, and to avoid discarding a necessary transmission packet as much as possible.

In order to solve the above problems, a communication device according to the present invention provides:
A first input portion of a packet comprising priority information in a header portion;
A second input portion of the packet;
First classification means for classifying the packet into a plurality of classes according to priority based on the priority information of the packet from the first input unit;
A first buffer unit that sequentially holds the packets from the first input unit for each class divided by the first classifying unit;
Second classifying means for classifying the packet into a plurality according to the priority order based on the priority information of the packet from the second input unit;
A second buffer unit that sequentially holds the packets from the second input unit for each class divided by the second classifying unit;
When either of the first buffer and the second buffer is set to a high priority and the classified classes are the same in the first classifying unit and the second classifying unit, A priority is given to the packets buffered in the first buffer and the second buffer, according to the priority order of the first buffer and the second buffer, and a higher priority is given. Transmission arbitration means for sequentially reading out the packets from the first buffer unit and the second buffer and sending them out as outputs,
It is characterized by providing.

  In the communication apparatus of the present invention having the above-described configuration, the packet header portion includes information on the priority order for transmission. Based on this information, the packet collision is arbitrated.

  In the communication apparatus according to the present invention, the packets are classified into a plurality of classes based on the priority information, and held in the buffer unit for each of the divided classes. Packets input through the first input unit are stored in the first buffer unit by being divided for each class. Further, packets input through the second input unit are held in the second buffer unit by being divided for each class.

  The first buffer unit and the second buffer unit are also given priorities for transmission. For example, when the priority order of the first buffer unit is higher, the transmission arbitration unit first sets the priority order of the first buffer unit to the first, second, third,. The priorities of all classes for both the first buffer unit and the second buffer unit are the first, third, fifth, etc. The classes with the first, second, third,... Priority are the second, fourth, sixth,...

  Then, the transmission arbitration means arbitrates the packets so that they are read out in order from the class packet with the highest priority and are transmitted.

  Thus, in the communication apparatus according to the present invention, the transmission arbitration means avoids a collision and automatically follows the priority of each packet even when the input timing of two input packets cannot be controlled. Mediation.

The relay device according to the present invention
Discrimination information for discriminating whether a packet is for management or data communication, transmission path identification information for identifying the transmission path of the packet connected between two points, and priority for transmission A relay device that relays the packet including the information in the header part,
A first interface for transmitting and receiving the packet to one communication partner;
A second interface for transmitting and receiving the packet to the other party of the communication;
Of the packets transmitted and received through the first interface, a third interface unit for transmitting and receiving the management packet, and of the management packet among the packets transmitted and received through the second interface A management packet bridge unit comprising a fourth interface unit for performing transmission and reception, and a first bridge unit for transferring the management packet between the third and fourth interfaces;
A fifth interface connected to the first interface, a sixth interface connected to the second interface, a seventh interface connected to the third interface, and the fourth interface; The management interface that transfers the data communication packet between the eighth interface to be connected, the first interface, and the second interface, and is input through the fifth or sixth interface. Packet for use is transferred to the management packet bridge unit through the seventh or eighth interface, and the management packet input through the seventh or eighth interface is sent to the fifth or sixth interface. Through the first or the second And the data packet bridge portion comprising a second bridge portion so as to transfer to the interface,
In a relay device comprising:
The second bridging unit of the data packet bridging unit sends a data communication packet input through the fifth interface to the sixth interface as a management packet sent from the eighth interface. A first bridge portion that transfers while arbitrating a collision with the data, and a data communication packet input through the sixth interface is sent to the fifth interface from the seventh interface A second bridge portion that transfers while arbitrating the collision with the packet of
Each of the first and second bridge portions is:
First classifying the data communication packet into a plurality of classes according to the priority order based on the priority information of the data communication packet from the fifth interface or the sixth interface Classification means,
A first buffer unit that sequentially holds the packets for data communication for each class divided by the first classifying unit;
Second classifying means for classifying the management packet into a plurality of classes according to priority based on the priority information of the management packet from the eighth or seventh interface; ,
A second buffer unit that sequentially holds the management packets for each of the classes classified by the second classifying unit;
When either of the first buffer and the second buffer is set to a high priority and the classified classes are the same in the first classifying unit and the second classifying unit, According to the priority order of the first buffer and the second buffer, the data communication packet or the management packet buffered in the first buffer and the second buffer is prioritized. Transmission arbitration that assigns ranks, reads out the data communication packet or the management packet from the first buffer unit and the second buffer sequentially from the highest priority, and sends it as an output. Means,
It is characterized by that.

  According to the relay device of the present invention having the above-described configuration, the bridge unit is divided into a management packet bridge unit that processes only management packets and a data packet bridge unit that relays and transfers only data communication packets. Therefore, the data packet bridge unit can relay and transfer a packet for data communication without worrying about processing performance for performing transmission path management (session management).

  According to the relay device of the present invention, in the data packet bridge unit, the data communication packets are divided into classes according to the priority information, held in the first buffer unit, and also used for management. Packets are classified into classes according to priority information and held in the first buffer unit.

  Then, in the same manner as in the communication apparatus described above, the transmission arbitration means determines the priority order as a whole for each class of the two buffer units, and according to the determined priority order, the first class packet having the higher priority order is set. Are read from the second buffer unit or the second buffer unit and transmitted.

  Therefore, according to the relay device of the present invention, the management packet and the data communication packet in the data packet bridge unit generated when the bridge unit is divided into the management packet bridge unit and the data packet bridge unit, Thus, it is possible to automatically perform arbitration according to the priority order of each packet.

  According to the communication device of the present invention, even when the input timing of two input packets cannot be controlled, collision can be avoided and arbitration can be automatically performed according to the priority order of each packet. it can.

  Further, according to the relay device according to the present invention, the bridge unit is divided into the management packet bridge unit and the data packet bridge unit without worrying about processing performance for performing transmission path management (session management). In addition to enabling relay transfer of data communication packets, the data packet bridge unit automatically avoids a collision between a management packet and a data communication packet, and automatically follows the priority of each packet. Mediation can be done.

  Hereinafter, the embodiment of the relay device according to the present invention will be described with reference to the drawings, taking as an example the case where the relay device according to the present invention is applied to the PPPoE bridge provided in the broadband modem / line terminator 4 in the communication system of FIG. . The embodiment of the communication apparatus according to the present invention is applied to data transmission arbitration processing for one of the WAN side or LAN side of the relay apparatus described below.

  FIG. 1 is a block diagram showing an outline of a configuration of a PPPoE bridge 30 as an embodiment of a relay apparatus according to the present invention. As shown in FIG. 1, the PPPoE bridge 30 of this embodiment includes switching hubs (hereinafter referred to as switches) 31 and 32 provided for the WAN side and the LAN side, a management packet bridge unit 33, and a data packet. And a bridge section 34.

  In this embodiment, the management packet bridge unit 33 includes a microcomputer (CPU) and is configured to execute the processing by software processing. In this example, the data packet bridge unit 34 has a hardware processing configuration by FPGA.

  The switch 31 includes a WAN side interface unit 35 and a MAC unit 36. The switch 32 includes a LAN side interface unit 37 and a MAC unit 38. The WAN side interface unit 35 is a physical layer function unit having a physical layer (PHY) function for connecting to a transmission path on the Internet side. In this example, the LAN-side interface unit 37 constitutes a physical layer function unit (PHY) having a physical layer function for connecting to Ethernet (registered trademark).

  The MAC units 36 and 38 are controller units for performing processing according to the protocol in order to perform communication through the WAN and the LAN. Without this, the MAC units 36 and 38 cannot satisfy, for example, Ethernet (registered trademark) standards. For example, there are various communication speeds according to the Ethernet (registered trademark) standard, such as 10BASE-T / 100BASE-TX / 1000BASE-T. Even if the communication speed changes, the MAC unit and the physical layer (PHY) ) Can be communicated at a speed corresponding to the change speed.

  The MAC unit 36 is provided between the WAN-side interface 35 unit serving as a physical layer function unit and the data packet bridge unit 34. The MAC unit 38 is provided between the LAN side interface unit 37 as a physical layer function unit and the data packet bridge unit 34.

  The MAC unit 36 is provided for a transmission line connected to the WAN connected to the WAN side interface unit 35. The transmission path may be a wired path using a cable or a wireless path. The MAC unit 38 is provided for a transmission line connected to the LAN connected to the LAN side interface unit 37. This transmission path may be a wired path using a cable or a wireless path.

  The management packet bridge unit 33 is provided with a MAC unit 301 for the WAN side and a MAC unit 302 for the LAN side.

  In the PPPoE bridge 30 of this embodiment, since the MAC units 36 and 38 are provided in the switch 31 and the switch 32, it is not necessary to provide the MAC unit in the data packet bridge unit 34.

  That is, when the MAC units 36 and 38 are not provided, the data packet bridge unit 34 needs to be provided with a MAC unit for the WAN side interface unit 35 and the LAN side interface 37 as physical layer function units. As for the MAC units 301 and 302 of the management packet bridge unit 33, the data packet bridge unit 34 needs to be provided with another MAC unit.

  That is, normally, the data packet bridge unit 34 needs to be provided with a total of four MAC units. However, in the configuration of the embodiment of FIG. 1, the switches 31 and 32 including the MAC units 301 and 302 are provided. By providing these, these four MAC units can be omitted, and an increase in cost can be suppressed.

  In the PPPoE 30 of this embodiment, an interface 401 is provided for the MAC unit 36 of the switch 31 on the WAN side, and an interface 402 is provided for the MAC unit 301 of the management packet bridge unit 33. An interface 403 is provided for the MAC unit 38 of the switch 32 on the LAN side, and an interface 404 is provided for the MAC unit 302 of the management packet bridge unit 33.

  In this embodiment, GMII (Gigabit Medium Independent Interface) is used for the interfaces 401 to 404 of the data packet bridge unit 34. Therefore, in the relay device of this embodiment, the transfer of the data packet through the data packet bridge unit 34 between the switch 31 and the switch 32 is performed at a high speed with a constant communication speed. In the relay apparatus of this embodiment, the management packet is transferred between the switch 31 and the switch 32 and the management packet bridge unit 33 through the data packet bridge unit 34 at a high speed with a constant communication speed. Is called.

  In the data packet bridge unit 34, a hard bridge circuit 405 for bridging and transferring data communication packets is provided. The hard bridge circuit 405 bridges and transmits a data communication packet on the LAN side to the LAN side, and a hard bridge circuit unit 405W that bridges and transmits the data communication packet on the LAN side to the WAN side. A hard bridge circuit unit 405L.

  The hard bridge circuit units 405W and 405L not only have a function of bridging and transferring data communication packets, but also arbitrate management packets and data communication packets sent from the management packet bridge unit 33. Packets are not discarded due to the collision between the two.

  In this case, in the PPPoE bridge 30 of this embodiment, the management packet and the data packet are transferred as follows.

  That is, when a packet input through the WAN side interface unit 35 and the MAC unit 36 of the switch 31 is a management packet, the data packet bridge unit 34 uses the management packet through a path from the interface 401 to the interface 402. It is sent to the bridge unit 33. The management packet bridge unit 33 receives the packet at the MAC unit 301 and reaches the MAC unit 302 through a bridge unit by software. Thereafter, the packet is transferred to the data packet bridge unit 34, transferred to the switch 32 through a path from the interface 404 to the interface 403, and sent to the LAN side through the MAC unit 38 and the LAN side interface unit 37 of the switch 32. Is done.

  When the packet input through the LAN side interface unit 37 and the MAC unit 38 of the switch 32 is a management packet, the data packet bridge unit 34 uses the management packet through a path from the interface 403 to the interface 404. It is sent to the bridge unit 33. In the management packet bridge unit 33, the MAC unit 302 receives the packet and reaches the MAC unit 301 through a software bridge unit. Thereafter, the packet is transferred to the data packet bridge unit 34, transferred to the switch 31 through a path from the interface 402 to the interface 401, and sent to the WAN side through the MAC unit 36 and the WAN side interface unit 35 of the switch 31. Is done.

  Further, when the packet input through the WAN side interface unit 35 and the MAC unit 36 of the switch 31 is a data communication packet, the data packet is passed from the interface 401 through the internal bridge path in the data packet bridge unit 34. It is transferred to the switch 32 through a route to the interface 402. Then, the data communication packet is sent to the LAN side through the MAC unit 38 and the LAN side interface unit 37 of the switch 32.

  When the packet input through the LAN side interface unit 37 and the MAC unit 38 of the switch 32 is a data communication packet, the data packet bridge unit 34 receives the packet from the interface 403 through the internal bridge path. It is sent to the switch 31 through a route to 404. Then, the data communication packet is sent to the WAN side through the MAC unit 36 and the WAN side interface unit 35 of the switch 31.

  As described above, the management packet bridge unit 33 has a software processing configuration. However, since only the management packet needs to be handled, the burden of the software processing is reduced and the performance is improved. It is also easy to manage the session with the management packet bridge unit 33.

  Further, since the data packet bridge unit 34 has a hardware processing configuration based on FPGA, bridge transfer of data communication packets can be performed at high speed at a so-called wire speed. In addition, in this case, the data packet bridge unit 34 need not consider the performance of the management packet bridge unit 33.

  In the above description, the processing operation for arbitration between the data communication packet and the management packet has not been described. Hereinafter, the configuration and processing operation of the data packet bridge unit 34 considering the arbitration will be further described. explain.

  FIG. 2 illustrates a more detailed configuration of the management packet bridge unit 33 and the data packet bridge unit 34 in the PPPoE bridge 30 of this embodiment.

  As shown in FIG. 2, the management packet bridge unit 33 includes a WAN driver 311 having a MAC 301 (not shown), a LAN driver 312 having a MAC 302 (not shown), and a soft bridge 313. And an upper application (abbreviated as upper application in the figure) 314 as software functions. That is, as described above, the management packet bridge unit 33 includes a microcomputer, and the microcomputer executes functions of each unit as software processing.

  The WAN driver 311 is connected to the WAN side path interface of the data packet bridge unit 34 and transmits / receives a management packet to / from the WAN side switch 31 via the data packet bridge unit 34. It is.

  The LAN driver 312 is connected to the interface on the LAN side of the data packet bridge unit 34 and transmits / receives a management packet to / from the LAN side switch 32 via the data packet bridge unit 34. It is.

  The soft bridge 313 has a function of performing management bridge transfer between the WAN driver 311 and the LAN driver 312.

  Further, as will be described later, the soft bridge 313 acquires the session ID of the established session from the PADS packet for notifying the session ID of the established session (transmission path), and acquires the session ID of the acquired session ID. In addition to notifying the upper application 314 of the start, control processing for setting the acquired session ID in the register of the data packet bridge unit 34 is performed in accordance with an instruction from the upper application 314.

  Further, the soft bridge 313 acquires the session ID of the session requested to be disconnected from the PADT packet of the disconnection request, notifies the upper application 314 of the session disconnection of the acquired session ID, and acquires the session ID according to the instruction of the upper application 314. Control processing is performed to clear the session ID for the register of the data packet bridge unit 34.

  Furthermore, when the soft bridge 313 receives a packet with a session ID of an unknown session other than the session managed by the upper application 314, the soft bridge 313 discards the packet, sends a session unknown notification to the upper application 314, and According to the instruction, it is also provided with a function of pretending to be a communication partner, that is, pretending to be a PPPoE client and a PPPoE server, and disconnecting the unknown session.

  In this embodiment, the host application 314 performs session management and controls the soft bridge 313 as described above.

  Further, the upper application 314 has a function capable of updating the program stored in the microcomputer of the management packet bridge unit 33 through the network, for example. That is, the host application 314 has a function for the PPPoE bridge unit 30 to access the Internet from itself. Then, when it is necessary to perform the access and there is no free session, the soft bridge 313 is instructed to impersonate a PPPoE client and a PPPoE server and disconnect any session to generate a free space. It also has a function that can.

  In addition to the hard bridge circuit unit 405W and the hard bridge circuit unit 405L described above, the data packet bridge circuit 405 includes a register unit 507 for holding a session ID and an access to the register unit 507 from the management packet bridge unit 33. And an interface 508 for receiving.

  The hard bridge circuit unit 405W includes a frame analysis unit 501, a distribution unit 502, and an arbitration unit 503. The hard bridge circuit unit 405L includes a frame analysis unit 504, a distribution unit 505, and an arbitration unit 506.

  In the hard bridge circuit unit 405W, the frame analysis unit 501 and the distribution unit 502 are provided in series in the path from the interface 401 to the interface 402 of the packet received from the MAC unit 36 of the switch 31 on the WAN side. An arbitration unit 503 is provided in the path from the interface 404 to the interface 403, and the distribution unit 502 and the arbitration unit 503 are connected to form a bridge path from the distribution unit 502 to the arbitration unit 503. That is, the distribution unit 502 and the arbitration unit 503 are connected to form a bridge path for bridge-transferring packets from the WAN side to the LAN side.

  In the hard bridge circuit unit 405L, the frame analysis unit 504 and the distribution unit 505 are provided in a series in the path from the interface 403 to the interface 404 of the packet received from the MAC unit 38 of the switch 32 on the LAN side. It is done. An arbitration unit 506 is provided in a path from the interface 402 to the interface 401, and the distribution unit 505 and the arbitration unit 506 are connected to form a bridge path from the distribution unit 505 to the arbitration unit 506. In other words, the distribution unit 505 and the arbitration unit 506 are connected to form a bridge path for bridge-transferring packets from the LAN side to the WAN side.

  Further, the session ID of the session established through the PPPoE bridge 30 is written to the register unit 507 of the data packet bridge unit 34 through the interface 508 by the soft bridge 313 of the management packet bridge unit 33. When the session is disconnected, the session ID in the register unit 507 is cleared by the upper application 314.

  Information on the session ID of the register unit 507 is supplied to the distribution units 502 and 505.

  The frame analysis unit 501 analyzes the header part of the PPPoE packet (PPPoE frame) sent from the WAN side, extracts the packet type (frame type) “ETHER TYPE” and the session ID, and extracts the extracted packet type information And the session ID are delivered to the distribution unit 502 together with the received packet.

  Based on the packet type information “ETHER TYPE”, the distribution unit 502 determines whether the received packet is a management packet or a data communication packet. When the distribution unit 502 determines that the received packet is a data communication packet, the distribution unit 502 compares the session ID received from the frame analysis unit 501 with the session ID set in the register unit 507, and The session ID is determined whether or not it has been done.

  The distribution unit 502 performs distribution processing to determine whether to pass the packet from the frame analysis unit 501 to the interface 402 or to the arbitration unit 503 based on the determination result. That is, the distribution unit 502 is configured to pass the packet to the management packet bridge unit 33 through the interface 402 when the packet is a management packet. The distribution unit 502 is configured to pass the packet to the arbitration unit 503 when the packet is for data communication and the session ID determination result is the same. The distribution unit 502 is configured to pass the packet to the management packet bridge unit 33 through the interface 402 when the session ID determination results do not match.

  Similarly, the frame analysis unit 504 analyzes the header part of the PPPoE packet (PPPoE frame) sent from the LAN side, extracts the packet type (frame type) “ETHER TYPE” and the session ID, and extracts the extracted packet The type information and the session ID are transferred to the distribution unit 505 together with the received packet.

  Based on the packet type information “ETHER TYPE”, the distribution unit 505 determines whether the received packet is a management packet or a data communication packet. When the distribution unit 505 determines that the received packet is a data communication packet, the distribution unit 505 further compares the session ID received from the frame analysis unit 501 with the session ID set in the register unit 507. The session ID is determined whether or not they match.

  The distribution unit 505 performs distribution processing of whether the packet from the frame analysis unit 504 is transferred to the interface 404 or the arbitration unit 506 based on the determination result. That is, the distribution unit 505 is configured to pass the packet to the management packet bridge unit 33 through the interface 404 when the packet is a management packet. Further, the distribution unit 505 is configured to pass the packet to the arbitration unit 506 when the packet is for data communication and the session ID determination result is the same. The distribution unit 505 is configured to pass the packet to the management packet bridge unit 33 through the interface 404 when the session ID determination results do not match.

  The frame analysis units 501 and 504 also extract the priority information of the packet included in the header part of the PPPoE packet (PPPoE frame), and distribute the priority information through the distribution units 502 and 505. Pass to 503 and 506.

  FIG. 3 shows a format example of the header part of the PPPoE frame in the case of IPv4. The high-order 6 bits of the field “TOS” of the IP header of FIG. 3 are information of priority called “DSCP”.

  FIG. 4 shows a format example of the header part of the PPPoE frame in the case of IPv6. The upper 6 bits of the field “TC” of the IP header in FIG. 4 are information of priority called “DSCP”.

  Arbitration units 503 and 506 are used for arbitration so as not to cause collision between packets from distribution units 502 and 505 and packets from interfaces 404 and 402. In this embodiment, the header unit of the PPPoE frame described above is used. Packet arbitration is performed based on the priority information of each packet included in the packet. The detailed configuration and processing operation of the arbitration units 503 and 506 will be described in detail later.

  With the above processing, the packet for data communication after the session is established is controlled so as to pass only the data packet bridge unit 34 (bridge transfer), and the management packet sent through the WAN or LAN, Unknown packets are sent to the management packet bridge unit 33.

  The distribution units 502 and 505 may be configured to pass all packets to the management packet bridge unit 33 side when the session ID is not set in the register unit 507.

  The management packet bridge unit 33 bridge-transfers a management packet received in the PPPoE session through the soft bridge 313. Then, the management packet bridge unit 33 acquires the session ID notified from the server in the PPPoE session, and sets it in the register unit 507 of the data packet bridge unit 34.

  When the management packet bridge unit 33 receives a disconnection request management packet (PADT packet) from the communication state, the management packet bridge unit 33 acquires the session ID included in the header of the PADT packet, and the session ID is used as a data packet. Clear from the register unit 507 of the bridge unit 34.

  Next, a sequence such as a connection sequence and a disconnection sequence executed in the PPPoE bridge 30 described above will be described to further explain processing operations in the PPPoE bridge 30 of this embodiment.

[Connection sequence; Fig. 5]
FIG. 5 is a sequence diagram for explaining an example of a connection sequence in the PPPoE bridge 30 according to the embodiment. FIG. 5 corresponds to the PPPoE communication sequence shown in FIG.

  As shown in FIG. 20, in the PPPoE session stage, the sequence (1)-(4) is performed. As shown in FIG. 5, it is assumed that there is a free session before this connection sequence is started. The high-order application 314 that performs session management grasps when a session is idle or during communication.

  First, a PADI packet for searching for a PPPoE server from a PPPoE client is input to the data packet bridge unit 34 through the LAN side interface unit 37. In the data packet bridge unit 34, the distribution unit 505 determines that the PADI packet is a management packet. Based on the determination result, the distribution unit 505 passes the PADI packet to the management packet bridge unit 33 through the interface 404.

  The management packet bridge unit 33 receives this PADI packet through the LAN driver 312 and transmits it (bridge transfer) to the WAN driver 311 through the soft bridge 313. The PADI packet from the WAN driver 311 is sent to the PPPoE server side through the WAN side interface unit 35 through the interface 402, the arbitration unit 506, and the interface 401 in the data packet bridge unit 34 in order.

  Next, a reply PADO packet is sent from the PPPoE server side, and this PADO packet is input to the data packet bridge unit 34 through the WAN side interface unit 35. In the data packet bridge unit 34, the distribution unit 502 determines that this PADO packet is a management packet. Based on the determination result, the distribution unit 502 passes the PADO packet to the management packet bridge unit 33 through the interface 402.

  The management packet bridge unit 33 receives this PADO packet through the WAN driver 311 and transmits it to the LAN driver 312 through the soft bridge 313 (bridge transfer). The PADO packet from the LAN driver 312 is sent to the PPPoE client side through the LAN side interface unit 37 through the interface 404, the arbitration unit 503, and the interface 403 in the data packet bridge unit 34 sequentially.

  Next, a PADR packet requesting the start of a session is sent from the PPPoE client side. The PADR packet is input to the data packet bridge unit 34 through the LAN side interface unit 37. In the data packet bridge unit 34, the distribution unit 505 determines that this PADR packet is a management packet. Based on the determination result, the distribution unit 505 passes the PADR packet to the management packet bridge unit 33 through the interface 404.

  The management packet bridge unit 33 receives this PADR packet through the LAN driver 312 and transmits it (bridge transfer) to the WAN driver 311 through the soft bridge 313. The PADR packet from the WAN driver 311 is sent to the PPPoE server side through the WAN side interface unit 35 through the interface 402, the arbitration unit 506, and the interface 401 in the data packet bridge unit 34 in order.

  Next, a PADS packet for notifying the session ID is sent from the PPPoE server side. The PADS packet is input to the data packet bridge unit 34 through the WAN side interface unit 35. In the data packet bridge unit 34, the distribution unit 502 determines that the PADS packet is a management packet. Based on the determination result, the distribution unit 502 passes the PADS packet to the management packet bridge unit 33 through the interface 402.

  The management packet bridge unit 33 receives this PADS packet through the WAN driver 311 and transmits it to the LAN driver 312 through the soft bridge 313 (bridge transfer). At this time, the soft bridge 313 acquires and holds the session ID from the PADS packet. Then, the soft bridge 313 passes the session start notification to the upper application 314 together with the extracted session ID.

  The host application 314 holds the received session ID for session management, and performs session management in which the session is in communication. Then, the upper application 314 sends a session start request to the soft bridge 313. Receiving this, the soft bridge 313 sets the session ID of the established session in the register unit 507 of the data packet bridge unit 34.

  By setting the session ID in the register unit 507, the data packet bridge unit 34 starts processing for bridge transfer with the LAN side interface unit 37.

  Thereafter, the soft bridge 313 transmits the PADS packet and sends it to the data packet bridge unit 34 through the LAN driver 312. As a result, the PADS packet is transferred to the LAN side interface through the data packet bridge unit 34 and sent to the PPPoE client side to establish a session.

  As described above, after the session is established, the higher-level application 314 manages communication. Then, the data communication packet exchanged through the WAN side interface unit 35 and the LAN side interface unit 37 in the PPP session is transmitted only through the data packet bridge unit 34 (bridge transfer) as shown by a dotted arrow in FIG. It becomes like this.

[Cutting sequence; FIG. 6]
FIG. 6 is a sequence diagram for explaining a disconnection sequence example in the PPPoE bridge 30 of the embodiment.

  As shown in FIG. 6, when a disconnect request PADT packet arrives from the PPPoE client side through the LAN side interface unit 37 during communication, the data packet bridge unit 34 uses the distribution unit 505 to manage the PADT packet for management. It is determined that the packet is. Based on the determination result, the distribution unit 505 passes the PADT packet to the management packet bridge unit 33 through the interface 404.

  The management packet bridge unit 33 receives this PADT packet through the LAN driver 312 and transmits it (bridge transfer) to the WAN driver 311 through the soft bridge 313. At this time, the soft bridge 313 takes out the session ID from the PADT packet and checks whether or not it matches the held session ID. If they match, the soft bridge 313 sends the session ID to the upper application 314 together with the taken session ID. Send session disconnect notification.

  The upper application 314 recognizes the session that has been disconnected based on the received session ID, and deletes the session ID and reflects it in the session management. Then, the upper application 314 sends a session disconnection request to the soft bridge 313.

  Receiving this, the soft bridge 313 clears the session ID of the disconnected session set in the register unit 507 of the data packet bridge unit 34. The soft bridge 313 deletes the session ID of the disconnected session from the session ID held by itself.

  By clearing the session ID of the register unit 507, the data packet bridge unit 34 stops processing of bridge transfer with the LAN side interface unit 37.

  Thereafter, the soft bridge 313 transmits the PADT packet and sends it to the data packet bridge unit 34 through the WAN driver 302. As a result, the PADT packet is transferred to the LAN side interface through the data packet bridge unit 34 and sent to the PPPoE server side.

  The PPPoE server that has received this PADT packet sends a PADT packet for response to the PPPoE client. As shown in FIG. 5, the response PADT packet is transmitted (bridge-transferred) by the management packet bridge unit 33 from the WAN side interface unit 35 via the data packet bridge unit 34, and the LAN side interface unit 37. And sent to the PPPoE client. As a result, the disconnection sequence is completed, and the disconnected session becomes free. Thereafter, the soft bridge 313 sends a session stop notification to the upper application 314. The host application 314 manages the session, assuming that the session is empty.

[Unknown session sequence; Fig. 7]
FIG. 7 is a sequence example when the PPPoE bridge 30 according to the embodiment receives an unknown packet that cannot be the situation at that time. For example, during communication in a PPP session, an LCP echo request (LCP Echo-REQ) packet is sent at an arbitrary timing to check whether the link (session) is alive. Therefore, in an idle state, the packet of the LCP echo request is a packet that cannot be present, and the session indicated by the session ID of the packet is an unknown session.

  The PPPoE bridge 30 in this embodiment impersonates a PPPoE client and a PPPoE server, and disconnects such unknown sessions.

  That is, as shown in FIG. 7, when communication is idle, when an LCP echo request packet arrives through the LAN side interface unit 37 in FIG. 7, the data packet bridge unit 34 sets the session ID in the register unit 507. Therefore, the LCP echo request packet is sent to the management packet bridge unit 33. The soft bridge 313 of the management packet bridge unit 33 determines that the LCP echo request packet in the empty state is an impossible packet, obtains a session ID from the packet, and then discards the packet.

  Then, the soft bridge 313 sends a session unknown notification to the upper application 314. The upper application 314 sends a session disconnection request to the soft bridge 313.

  Receiving this, the soft bridge 313 executes the session disconnection sequence by impersonating both parties of communication, that is, impersonating a PPPoE client and a PPPoE server.

  That is, the soft bridge 313 sends an LCP disconnection request (LCP Term-REQ) packet from the LAN side interface unit 37 to the PPPoE client through the data packet bridge unit 34 and also from the WAN side interface unit 35 to the PPPoE server. .

  The response (LCP Term-ACK) packet is sent from the PPPoE client and PPPoE server that have received the LCP disconnection request packet. In the same manner as described above, the response packet is received by the soft bridge 313 of the management packet bridge unit 33 via the data packet bridge unit 34, and the soft bridge 313 discards the received response packet.

  Then, the soft bridge 313 sends a session disconnection PADT packet from the LAN side interface unit 37 to the PPPoE client through the data packet bridge unit 34 and also from the WAN side interface unit 35 to the PPPoE server.

  The PPPoE client and PPPoE server that have received the session disconnection PADT packet send a PADT packet as a response. Similarly to the above, the PADT packet of the response is received by the soft bridge 313 of the management packet bridge unit 33 via the data packet bridge unit 34, and the soft bridge 313 discards the received PADT packet of the response. Thereafter, the soft bridge 313 sends a session stop notification to the upper application 314.

[Disconnection request sequence; FIG. 8]
FIG. 8 is a sequence example when the PPPoE bridge 30 according to the embodiment disconnects a communication session in order to access the PPPoE server.

  That is, the upper application 314 sends a disconnection request for the session being communicated to the soft bridge 313. Receiving this, the soft bridge 313 clears the session ID of the session in communication set in the register unit 507 of the data packet bridge unit 34. Then, the soft bridge 313 deletes the session ID of the disconnected session from the session ID held by itself.

  By clearing the session ID of the register unit 507, the data packet bridge unit 34 stops processing of bridge transfer with the LAN side interface unit 37.

  Thereafter, the soft bridge 313 impersonates a PPPoE client and a PPPoE server and executes a session disconnection sequence. Since the session disconnection sequence is the same as that shown in FIG. 7, the description thereof is omitted here.

  Although not shown in FIG. 8, after receiving the session stop notification from the soft bridge 313, the upper application 314 receives a specific server via a PPPoE server, for example, for updating its software program. Can be accessed.

[Processing in Management Packet Bridge 33]
9 and 10 are flowcharts of processing for the management packet bridge unit 33 to execute the connection sequence, the disconnection sequence, and the unknown session disconnection sequence described above. Note that the flowchart of the process for forming the above-described disconnection request sequence in FIG. 8 is omitted. Each step of the flowcharts of FIG. 9 and FIG. 10 is executed by the microcomputer constituting the management packet bridge unit 33, and includes processing of the soft bridge 313 and processing of the upper application 314.

  As shown in FIG. 9, the management packet bridge unit 33 checks the header portion of the received packet (step S101), and determines whether or not the received packet is a PADS packet that notifies the session ID of the established session. (Step S102). If it is determined in step S102 that the received packet is a PADS packet, a session ID is acquired from the PADS packet and held, and session start is managed (step S103).

  Then, the management packet bridge unit 33 sets the session ID acquired in step S103 in the register unit 507 of the data packet bridge unit 34 (step S104), and transmits the received PADS packet through the soft bridge 313 (step S105). ). Then, the process returns to step S101 to check the next packet.

  When the management packet bridge unit 33 determines in step S102 that the received packet is not a PADS packet, the management packet bridge unit 33 determines whether or not the received packet is a PADT packet for session disconnection notification (step in FIG. 10). S111).

  When it is determined in step S111 that the received packet is a PADT packet, the management packet bridge unit 33 acquires a session ID from the PADT packet, recognizes session disconnection of the session ID, and reflects it in session management. (Step S112).

  Then, the management packet bridge unit 33 clears the session ID stored and held in the register unit 507 of the data packet bridge unit 34 (step S113). In step S105, the packet PADT is transmitted. After that, the process returns to step S101, and the processes in and after step S101 are repeated.

  If it is determined in step S111 that the received packet is not a PADT packet, the management packet bridge unit 33 determines whether the packet is an unknown packet that cannot be in that state (step S114). If it is determined that the packet is not an unknown packet, the management packet bridge unit 33 proceeds to step S105, transmits the packet PADT, returns to step S101, and repeats the processing after step S101.

  If it is determined in step S114 that the packet is an unknown packet, the management packet bridge unit 33 discards the packet and impersonates both parties of the communication to execute a disconnection sequence (step S116). And it returns to step S101 and repeats the process after this step S101.

[Description of packet distribution processing operation in data packet bridge unit 34]
In this embodiment, the data packet bridge unit 34 has a hardware configuration based on the FPGA as described above. In order to clarify the packet distribution processing operation, the processing procedure will be described with reference to a flowchart. To do.

  FIG. 11 shows a flowchart for explaining a procedure of packet distribution processing in which the distribution unit 502 or the distribution unit 505 transfers the packet to the data packet bridge unit 34 or to the management packet bridge unit 33. In the flowchart of FIG. 11, processing of information for arbitration between the management packet and the data communication packet is omitted.

  When the distribution unit 502 or the distribution unit 505 receives the packet (step S201), the distribution unit 502 or the distribution unit 505 checks whether the session ID is set in the register unit 507 (step S202), and when the session ID is not set in the register unit 507, The packet is transferred to the management packet bridge unit 33 (step S207).

  When it is determined in step S202 that the session ID is set in the register unit 507, the distribution unit 502 or the distribution unit 505 refers to the packet type in the header portion of the received packet, and the packet is managed. It is determined whether the packet is a packet for data communication (step S204).

  When the distribution unit 502 or the distribution unit 505 determines that the received packet is a management packet, the distribution unit 502 or the distribution unit 505 passes the packet to the management packet bridge unit 33 (step S207).

  When the distribution unit 502 or the distribution unit 505 determines that the received packet is a data communication packet, the distribution unit 502 or the distribution unit 505 compares the session ID of the packet with the session ID held in the register unit 507. Then, it is determined whether or not they match (step S205). When it is determined that the two match, the distribution unit 502 or the distribution unit 505 transmits the packet through the data packet bridge unit 23 (step S206).

  If it is determined in step S205 that the session ID of the packet does not match the session ID held in the register unit 507, the distribution unit 502 or the distribution unit 505 determines that the received packet is a management packet bridge. The data is transferred to the unit 33 (step S207).

[Arbitration between management packet and data communication packet]
Arbitration processing by the arbitration units 503 and 506 of the data packet bridge unit 34 to prevent the management packet and the data communication packet from colliding and being discarded will be further described below.

  The hard bridge circuit units 405W and 405L constituting the hard bridge circuit 405 of the data packet bridge unit 34 include frame analysis units 501 and 504, distribution units 502 and 505, and arbitration units 503 and 506, respectively. The same processing operation is performed. Therefore, in the following description, in order to avoid complexity of description, the configuration and processing operation of one hard bridge circuit unit 405L will be described as an example, and description of the hard bridge circuit unit 405W will be omitted.

  FIG. 12 is a block diagram of the hard bridge circuit unit 405L of the data packet bridge unit 34 including a detailed configuration example of the arbitration unit 503. Needless to say, the arbitration unit 506 also has the same configuration as the arbitration unit 503. In FIG. 12, the register unit 507 for packet distribution processing described above is omitted in order to avoid complicated description.

  As shown in FIG. 12, in this embodiment, the arbitration unit 503 includes a classification unit 601 connected to the distribution unit 502, a queue status holding unit 602 for data communication packets, and a data communication packet. A buffer unit 603, a transmission arbitration unit 604, a frame analysis unit 605 that receives a management packet sent through the interface 404, a classification unit 606 connected to the frame analysis unit 605, and a management packet The queue status holding unit 607 and a management packet buffer unit 608 are configured.

  The frame analysis unit 501 performs processing for packet arbitration from the packet received from the interface 401 from the upper 6 bits of the field “TOS” or “TC” in the header portion shown in FIGS. 3 and 4 described above. The DSCP information is extracted as priority order information and delivered to the distribution unit 502. When the packet from the frame analysis unit 501 is a data communication packet, the distribution unit 502 passes the packet to the classification unit 601 together with the received priority information.

  Also, the frame analysis unit 605 determines the priority 6 bits of DSCP information of the field “TOS” or “TC” of the header shown in FIGS. 3 and 4 from the management packet received from the interface 404. The information is extracted as the information and transferred to the classifying unit 606.

  The classifying units 601 and 606 have the same configuration. In this example, the priority order information is analyzed and classified into a plurality of classes according to the priority order. In this example, classes are classified into four levels of class 0, class 1, class 2, and class 3 in order from the highest priority.

  Then, the classification units 601 and 606 register the queue status of the packet in the queue status holding units 602 and 607 according to the classification result.

  The queue status holding units 602 and 607 are configured by a memory composed of, for example, a DRAM (Dynamic Random Access Memory), and each of the four stages of class 0, class 1, class 2, and class 3 has a packet queue state ( (Transmission standby state) can be registered.

  FIG. 13 shows the format of the queue status in this example. As shown in FIG. 13A, the queue status is 16-bit information in this example. Then, as shown in FIG. 13B, 1 bit “E” in the queue status indicates whether it is set (with a standby packet) or empty (without a standby packet). Information. The other 1 bit “V” is validity information as to whether or not the standby packet is normally set as shown in FIG.

  Then, as shown in FIG. 13C, the queue status holding units 602 and 607 have four types of queue classes 0 corresponding to the four levels of class 0, class 1, class 2, and class 3 according to priority. The storage unit is divided into queue class 1, queue class 2, and queue class 3. In this example, 64 queue statuses can be registered in each queue class. That is, a maximum of 64 packets can be buffered in each of the four stages of class 0, class 1, class 2, and class 3.

  The classifying units 601 and 606 register the queue status of the received packet in the storage area of the queue class corresponding to the class obtained as a result of the classification determination described above in the queue status holding unit 607. .

  The classifying units 601 and 606 also write and buffer the packets in the storage areas corresponding to the classes obtained as a result of the classifying determination of the buffer units 603 and 608.

  For example, in this embodiment, although not shown, the buffer units 603 and 608 are four first in first out (FIFO) memories each corresponding to one of four classes. It is configured.

  Accordingly, the classifying units 601 and 606 write the packet into the FIFO memory of the class corresponding to the classification result among the four FIFO memories of the buffer units 603 and 608. The capacity of each FIFO memory can store a packet corresponding to the maximum number of statuses stored in the queue status holding units 602 and 607. If the FIFO memory is full, a new packet is stored. When it arrives, the new packet will be discarded.

  The transmission arbitration unit 604 transmits (sends) packets to the interface 403 side while associating the queue statuses of the classes of the queue status holding units 602 and 607 with the FIFO memories of the corresponding classes of the buffer units 603 and 608. Is determined and read.

  As described above, in each of the buffer units 603 and 608, in this embodiment, packets are buffered by being classified into four levels of class 0, class 1, class 2, and class 3. Accordingly, when packets having the same priority are present as the next queue in the buffer unit 603 and the buffer 608, it is necessary to select one with priority.

  In this embodiment, the management packet has a higher priority than the data communication packet. In this embodiment, the information of the packet for data communication is determined in this way in consideration of being able to be retransmitted.

  Therefore, the four-stage class 0, class 1, class 2, and class 3 FIFO memories (eight FIFO memories) of the buffer units 603 and 608 are respectively shown in FIG. 14 for the buffer units 603 and 608. Priorities such as those indicated by circle numbers are given.

  That is, the priority order of the four-stage class 0, class 1, class 2, and class 3 FIFO memories in the buffer unit 608 is the first, third, fifth, and seventh. Also, the priority order of the four-stage class 0, class 1, class 2, and class 3 FIFO memories in the buffer unit 603 is the second, fourth, sixth, and eighth.

  Therefore, the transmission arbitration unit 604 first refers to the queue status of the queue class 0 of the queue status holding unit 607 and, when determining that there is a waiting packet, reads the packet from the class 0 FIFO memory of the buffer unit 608, and It is made to transmit through 403.

  Then, the transmission arbitration unit 604 refers to the queue status of the queue class 0 of the queue status holding unit 607 and, when determining that there is no waiting packet, refers to the queue status of the queue class 0 of the queue status holding unit 602 and waits. When it is determined that there is a packet, the packet is read from the class 0 FIFO memory of the buffer unit 603 and transmitted through the interface 403.

  Similarly, when there is no higher priority queue (waiting packet), the transmission arbitration unit 604 refers to the lower queue status, and determines that there is a waiting packet, the buffer unit 603 or 608. The packet is read from the FIFO memory of the corresponding class, and transmitted through the interface 403.

  Through the arbitration processing operation of the transmission arbitration unit 604 described above, arbitration can be performed so that a packet having a high priority is transmitted with priority while avoiding a collision between a management packet and a data communication packet.

[Description of processing operations of each major part in arbitration]
As described above, the data packet bridge unit 34 has a hardware configuration by FPGA. In order to clarify the processing operation of each main unit in the arbitration unit, the processing operation of each main unit will be described below. Each will be described with reference to flowcharts.

<Frame analysis section>
FIG. 15 is a flowchart for explaining the processing operation of the frame analysis unit 501 or 504 or the frame analysis unit 605 (the same applies to the frame analysis unit of the hard bridge circuit unit 405W). Here, the operation of the frame analysis unit 501 will be described.

  First, the frame analysis unit 501 receives a PPPoE frame, that is, a PPPoE packet (step S301). Next, the frame analysis unit 501 determines whether or not the frame has been correctly received (step S302). When it is determined that the frame has been correctly received, the header portion of the PPPoE frame is immediately analyzed (step S304).

  If it is determined in step S302 that the data has not been received correctly, an error status is set (step S303), and then the process proceeds to step S304 to perform processing for analyzing the header portion of the PPPoE frame.

  Next, as the analysis result in step S303, the packet type “ETHER_TYPE” information, the priority DSCP information, the session ID, and the like are extracted (step S305), and the extracted information is passed to the subsequent units. It is encoded as information and passed to a subsequent processing unit (step S306). And it returns to step S301 and repeats the process from this step S301.

<Distributor>
The processing of the distribution unit 502 and the distribution unit 505 that has received information from the frame analysis unit 501 or the frame analysis unit 504 is as shown in FIG. Here, the processing of the distribution unit 502 will be described.

  That is, the distribution unit 502 uses the packet type “ETHER_TYPE” information and the session ID in the encoded frame information from the frame analysis unit 501, as described above, the received packet is sent to the management packet bridge unit. It is determined whether the data should be sent to 33 or transmitted through the hard bridge circuit 405 (step S311).

  Then, as a result of the determination, the distribution unit 502 determines whether or not the transmission destination of the received packet is the management packet bridge unit 33 (step S312), and when determining that the transmission destination is the management packet bridge unit 33 The packet is passed to the management packet bridge unit 33 through the interface 402. At this time, it is not necessary to pass the encoded frame information to the management packet bridge unit 33.

  When it is determined in step S312 that the transmission destination is not the management packet bridge unit 33, the distribution unit 502 passes the packet to the classification unit 601 of the arbitration unit 503 with at least priority information of the encoded frame information. (Step S314). In step S313 or step S314, when the packet transmission is completed, the process returns to step S311 and the above processing is repeated.

<Classification part>
The processing operation in the classifying unit 601 or 606 (the same applies to the classifying unit of the hard bridge circuit unit 405W) is as shown in FIG. Here, the operation of the classification unit 601 will be described.

  The classifying unit 601 searches for table information for classification in four stages prepared in advance for priority information in the received encoded frame information (step S321), and the packet of any class Is determined (step S322).

  Next, the classification unit 601 determines whether or not the error status included in the encoded frame information is set (see step S343 in FIG. 15) (step S323), and when the error status is set, The packet is discarded (step S324), the process returns to step S321, and the process from step S321 is repeated.

  If the classification unit 601 determines in step S323 that the error status is not set, the packet is written into the FIFO memory corresponding to the class determined in step S322 in the buffer unit 603 and queued. (Step S325).

  Next, the classifying unit 601 registers the queue status in the queue class area corresponding to the class determined in step S322 in the queue status holding unit 607 (step S326). And it returns to step S321 and repeats the process after this step S321.

  As shown in FIG. 13, when the classification unit 601 starts to write a packet to the FIFO memory, it sets the queue status bit “E” from “0” to “1”, and The queue status is reflected in the queue status. When the packet is normally written into the FIFO, the classification unit 601 sets the bit “V” of the queue status to “1”. However, when the packet is not normally written into the FIFO, the classifying unit 601 sets the bit “V” of the queue status to “0”.

  Further, the bit “E” of the queue status causes the transmission arbitration unit 604 to return to “0” when the transmission arbitration unit 604 completes packet transmission.

<Transmission arbitration unit>
The processing operation in the transmission arbitration unit 604 (same as the transmission arbitration unit of the hard bridge circuit unit 405W) is as shown in FIG.

  The transmission arbitration unit 604 determines whether there is a packet (queue) waiting for transmission in the buffer unit 603 or 608 (step S331). In this case, as described above, the transmission arbitration unit 604 determines whether or not there is a queue from the buffer unit 608 side having a higher priority.

  When it is determined that there is a queue in the buffer unit 603 or 608, the transmission arbitration unit 604 determines the queue status of the queue status holding unit 602 or 607 corresponding to the buffer unit that is determined to have the queue from the highest priority. Search to find the queue status of the packets queued in the buffer. If it is determined that there are queues in both the buffer units 603 and 608, the queue statuses of the buffer units 603 and 608 are alternately searched according to the above-described priority (step S332).

  Then, the transmission arbitration unit 604 determines a queue having the highest priority among queued items as a result of the search (step S333). Then, the transmission arbitration unit 604 refers to the queue status (bit “V”) of the queue and checks whether or not the packet is valid data (step S334).

  Then, the transmission arbitration unit 604 determines whether it is invalid as a result of the check and should be discarded (step S335). When it is determined that it should be discarded, the packet is discarded without being transmitted (step S336). . When the discarding process is completed, the queue status is updated (step S338), and then the process returns to step S331 to repeat the process from step S331.

  If it is determined in step S335 that the packet is valid data and should not be discarded, the transmission arbitration unit 604 performs processing for transmitting the packet through the interface 403 (step S337). When the transmission process is completed, the queue status is updated (step S338), and then the process returns to step S331 to repeat the process from step S331.

[Other Embodiments and Modifications]
In the above-described embodiment, the data packet bridge unit 34 has a hardware configuration using an FPGA, but may have a hardware configuration in which each unit has an individual circuit configuration. Further, the data packet bridge unit 34 may be configured by a DSP.

  Further, the management packet bridge unit 33 may be configured as a DSP.

  Also, the transmission path connected to the WAN side interface unit 35 and the LAN side interface unit 37 may be a wired path using a cable or a wireless path.

  Moreover, although the above-mentioned embodiment demonstrated the case where the relay apparatus was applied to the PPPoE bridge | bridging included in a broadband modem / line terminator, the relay apparatus of this invention can also be provided in a router or a gateway. .

  Moreover, although the above-mentioned embodiment is a case where this invention is applied to a relay apparatus, it is applied in all the cases where the communication apparatus which handles a PPPoE frame avoids the collision of the input packet from two paths, and arbitrates. Is possible.

  In the above description, the communication protocol is PPPoE. However, the present invention can also be applied to a communication protocol having the same format as PPPoE.

It is a block diagram which shows the outline | summary of the structural example at the time of using embodiment of the relay apparatus by this invention as a PPPoE bridge | bridging. FIG. 2 is a block diagram illustrating a detailed configuration example of a management packet bridge unit 33 and a data packet bridge unit 34 of the PPPoE bridge of FIG. 1. It is a figure for demonstrating an example of the format of a PPPoE frame. It is a figure for demonstrating the other example of the format of a PPPoE frame. It is a sequence diagram for demonstrating the connection sequence in the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a sequence diagram for demonstrating the cutting sequence in the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a sequence diagram for demonstrating the unknown session disconnection sequence in the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a sequence diagram for demonstrating the cutting | disconnection request | requirement sequence in the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a figure which shows a part of flowchart for operation | movement description of the management packet bridge | bridging part of the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a figure which shows a part of flowchart for operation | movement description of the management packet bridge | bridging part of the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a figure which shows the flowchart for operation | movement description of a part of data packet bridge part of the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a block diagram which shows the specific structural example of the principal part of the PPPoE bridge | bridging which is embodiment of the relay apparatus by this invention. It is a figure used in order to demonstrate the example of a specific structure of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a figure used in order to demonstrate the example of a specific structure of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a flowchart used in order to demonstrate operation | movement of the process part which comprises the specific structural example of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a flowchart used in order to demonstrate operation | movement of the process part which comprises the specific structural example of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a flowchart used in order to demonstrate operation | movement of the process part which comprises the specific structural example of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a flowchart used in order to demonstrate operation | movement of the process part which comprises the specific structural example of the principal part of the PPPoE bridge which is embodiment of the relay apparatus by this invention. It is a figure which shows the structure of an example of the communication system which used embodiment of the relay apparatus by this invention as a PPPoE bridge. It is a sequence diagram for demonstrating the sequence at the time of the session establishment of PPPoE. It is a figure for demonstrating the frame format of PPPoE. It is a block diagram for demonstrating the structural example of the conventional PPPoE bridge | bridging. It is a block diagram for demonstrating the structural example of the new PPPoE bridge proposed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 30 ... PPPoE bridge, 33 ... Management packet bridge part, 34 ... Data packet bridge part, 313 ... Soft bridge, 405 ... Hard bridge circuit, 501, 504, 605 ... Frame analysis part, 502, 505 ... Distribution part, 503,506 ... arbitration unit, 507 ... register unit, 601 and 606 ... classifying unit, 603 and 608 ... buffer unit

Claims (4)

A first input portion of a packet comprising priority information in a header portion;
A second input portion of the packet;
First classifying means for classifying the packet into a plurality of classes according to priority based on the priority information of the packet from the first input unit;
A first buffer unit that sequentially holds the packets from the first input unit for each class divided by the first classifying unit;
Second classifying means for classifying the packet into a plurality of classes according to priority based on the priority information of the packet from the second input unit;
A second buffer unit that sequentially holds the packets from the second input unit for each class divided by the second classifying unit;
When either of the first buffer and the second buffer is set to a high priority and the classified classes are the same in the first classifying unit and the second classifying unit, A priority is given to the packets buffered in the first buffer and the second buffer, according to the priority order of the first buffer and the second buffer, and a higher priority is given. Transmission arbitration means for sequentially reading out the packets from the first buffer unit and the second buffer and sending them out as outputs,
A communication apparatus comprising: The communication device according to claim 1,
For each of the first buffer unit and the second buffer unit, for each class, at least for each packet including information on whether the packet has been written and whether the packet has been written correctly Comprising first and second status information holding means for holding status information;
The transmission arbitration unit refers to the status information and determines a packet to be read while determining whether or not the packet is held in each class of the first buffer unit and the second buffer unit. The communication apparatus determines whether to output or discard a packet read from the first buffer unit or the second buffer unit based on the status information. Discrimination information for discriminating whether a packet is for management or data communication, transmission path identification information for identifying the transmission path of the packet connected between two points, and priority for transmission A relay device that relays the packet including the information in the header part,
A first interface for transmitting and receiving the packet to one communication partner;
A second interface for transmitting and receiving the packet to the other party of the communication;
Of the packets transmitted and received through the first interface, a third interface unit for transmitting and receiving the management packet, and of the management packet among the packets transmitted and received through the second interface A management packet bridge unit comprising a fourth interface unit for performing transmission and reception, and a first bridge unit for transferring the management packet between the third and fourth interfaces;
A fifth interface connected to the first interface, a sixth interface connected to the second interface, a seventh interface connected to the third interface, and the fourth interface; The management interface that transfers the data communication packet between the eighth interface to be connected, the first interface, and the second interface, and is input through the fifth or sixth interface. Packet for use is transferred to the management packet bridge unit through the seventh or eighth interface, and the management packet input through the seventh or eighth interface is sent to the fifth or sixth interface. Through the first or the second And the data packet bridge portion comprising a second bridge portion so as to transfer to the interface,
In a relay device comprising:
The second bridging unit of the data packet bridging unit sends a data communication packet input through the fifth interface to the sixth interface as a management packet sent from the eighth interface. A first bridge portion that transfers while arbitrating a collision with the data, and a data communication packet input through the sixth interface is sent to the fifth interface from the seventh interface A second bridge portion that transfers while arbitrating the collision with the packet of
Each of the first and second bridge portions is:
First classifying the data communication packet into a plurality of classes according to the priority order based on the priority information of the data communication packet from the fifth interface or the sixth interface Classification means,
A first buffer unit that sequentially holds the packets for data communication for each class divided by the first classifying unit;
Second classifying means for classifying the management packet into a plurality of classes according to priority based on the priority information of the management packet from the eighth or seventh interface; ,
A second buffer unit that sequentially holds the management packets for each of the classes classified by the second classifying unit;
When either of the first buffer and the second buffer is set to a high priority and the classified classes are the same in the first classifying unit and the second classifying unit, According to the priority order of the first buffer and the second buffer, the data communication packet or the management packet buffered in the first buffer and the second buffer is prioritized. Transmission arbitration that assigns ranks, reads out the data communication packet or the management packet from the first buffer unit and the second buffer sequentially from the highest priority, and sends it as an output. Means,
A relay device comprising: The relay device according to claim 3,
The management packet bridge unit
The management packet received through the data packet bridge unit is determined, the management packet is returned to the data packet bridge unit, and the transmission path identification of the transmission path where the management packet is established When it is determined that the information is for notification, the transmission path identification information is held in the data packet bridge unit,
The data packet bridge unit is
The transmission path identification information from the management packet bridge unit is received and held, and the transmission path identification information included in the packet received through the first or second interface and the held transmission path identification information And a packet whose discrimination information included in the packet is for data communication is transferred to the second or first interface through its own bridge unit, and other packets are the management packet A relay apparatus, wherein the packet is passed to a bridge unit and a packet from the management packet bridge unit is sent to the first or second interface.

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