JP2005064803A - Packet transfer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a package transfer apparatus which can surely perform a packet transfer processing even for a packet constituted by using a plurality of protocols. <P>SOLUTION: The package transfer apparatus includes a plurality of packet transfer processing means for performing the transfer processing of the packet received according to a protocol used in a layer 2 or a layer 3; and a memory for storing receiving processing responsible information for defining the package transfer processing means for performing the receiving processing of the packet based on a type of the protocol to which the received packet belongs, a header or the packet or a payload part. The packet transfer processing means decides the packet transfer processing means for succeedingly performing the receiving processing to the received packet based on the type of the protocol of the packet, the header of the packet or the payload part, and the receiving processing responsible information when the packet is received. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a packet transfer apparatus that performs transfer processing of IP packets, MPLS packets, Ethernet (registered trademark) frames, PoS frames, and the like.

  Conventionally, as a transfer processing method for transferring a packet such as an IP packet, an MPLS packet, an Ethernet (registered trademark) frame, or a PoS frame, for example, Ethernet (registered trademark) that performs packet transfer processing of the layer 2 protocol to layer 2 There is a configuration having a processing block and a PoS processing block, and having an IP processing block and an MPLS processing block for performing packet transfer processing of the layer 3 protocol in layer 3.

  The operation will be described by taking as an example the case of performing transmission / reception processing of IP packets on Ethernet (registered trademark). The Ethernet (registered trademark) frame received from the layer 1 is received and processed by the Ethernet (registered trademark) processing block, and it is determined from the protocol information indicated in the Ethernet (registered trademark) frame header that the layer 3 protocol is IP. Pass the processed packet to the processing block and request reception processing.

  The IP processing block performs IP packet reception processing, determines that the packet should be transmitted on the Ethernet (registered trademark), performs IP packet transmission processing inside the IP processing block, and then performs Ethernet (registered trademark). Send the processed packet to the processing block and request transmission processing. The Ethernet (registered trademark) processing block performs transmission processing, and then transmits the processed packet on layer 1.

JP-A-5-63749 (pages 2 to 6)

  However, in the conventional method, the combination of the L2 protocol and the L3 protocol is considered to be flexible, but there is a problem that the following cases that occur in the IP protocol cannot be handled. .

  For example, the Ethernet (registered trademark) frame payload is an MPLS packet, and the Ethernet (registered trademark) frame is transferred as the payload of the MPLS packet, so that the L2 protocol and the L3 protocol cannot be hierarchized in a free combination. . That is, packet transfer processing using any combination of the L2 protocol and the L3 protocol cannot be performed.

  For example, when the payload of an Ethernet (registered trademark) frame is an MPLS packet, the payload of the Ethernet (registered trademark) frame is an IP packet, and the payload of the IP packet is an MPLS packet. , The payload of the Ethernet (registered trademark) frame is an MPLS packet, and the payload of the MPLS packet is an MPLS packet, so that it cannot be executed in a plurality of protocol layers.

  As a technique for a packet using such a plurality of protocols, for example, there is a technique for standardizing an interface between the L2 protocol and the L3 protocol and exchanging data between any L2 protocol and L3. Thereby, an arbitrary combination is possible between the elements of one L3 protocol set and the elements of the L3 protocol set, and one L3 protocol is connected to a plurality of L2 protocols (see Patent Document 1).

  However, such a method cannot cope with a case where another L2 / L3 protocol is layered on top of the L3 protocol, and for a packet configured using a plurality of protocols. In some cases, packet transfer processing cannot be performed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a packet transfer apparatus capable of reliably realizing packet transfer processing even for packets configured using a plurality of protocols. It is said.

  In order to achieve the above object, a packet transfer apparatus according to the present invention includes a plurality of packet transfer processing means for executing transfer processing of a received packet according to a protocol used in layer 2 or layer 3, and a protocol to which the received packet belongs. A memory storing reception processing information for defining packet transfer processing means for executing reception processing of the packet based on the type and the header or payload portion of the packet, and the packet transfer processing means receives the packet Determining the packet transfer processing means for executing the next reception process on the received packet based on the protocol type of the packet and the header or payload portion of the packet and the reception processing charge information. Features.

  According to the present invention, when packet transfer processing is executed by a plurality of packet transfer processing means according to a protocol used in layer 2 or layer 3, the packet transfer processing means receives the packet protocol when receiving the packet. Next, the packet transfer processing means for executing the reception process on the received packet is determined based on the type of packet, the header or payload portion of the packet, and the reception processing charge information.

  Thereby, in the packet reception processing, after the connection relation between the packet transfer processing means in accordance with the contents of the received packet, specifically, the reception processing of one packet transfer processing means is performed, another packet transfer processing means The relationship is determined unambiguously without explicitly specifying the relationship of performing reception processing, and reception processing is performed by combining arbitrary packet transfer processing means. That is, the reception process is performed by hierarchizing the L2 protocol and the L3 protocol in any combination.

  In the present invention, a packet is a general term for an information transfer unit such as an Ethernet (registered trademark) frame, an MPLS packet, and an IP packet. Therefore, a packet includes an information transfer unit having a different name, such as an Ethernet (registered trademark) frame, a PoS frame, or the like.

  According to this invention, when the packet transfer processing means receives a packet, the packet transfer processing means performs the following on the packet received based on the protocol type of the packet, the header or payload portion of the packet, and the reception processing charge information: The packet transfer processing means for executing the reception process is determined. Thereby, in the packet reception processing, the connection relationship between the packet transfer processing means in accordance with the contents of the received packet, that is, after the reception processing of one packet transfer processing means is performed, the reception processing of another packet transfer processing means Can be uniquely determined, and reception processing can be performed by combining arbitrary packet transfer processing means. Therefore, according to the present invention, desired packet transfer processing can be realized for packets using a plurality of protocols by flexibly combining packet transfer processing means.

  Exemplary embodiments of transfer according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

  FIG. 1 is a principal block diagram of a packet transfer apparatus according to an embodiment of the present invention, and shows a peripheral portion of an arithmetic processing unit that controls packet transfer processing. This transfer apparatus includes an arithmetic processing unit 1, a reception processing correlation table 2, a transmission processing correlation table 3, and a packet transfer processing functional block specific data table 4.

  The arithmetic processing unit 1 is an arithmetic processing unit having a plurality of packet transfer processing function blocks which are packet transfer processing means for executing transfer processing of received packets in accordance with a protocol used in layer 2 or layer 3. The packet transfer processing function block is based on the data shown in the reception process association table 2, the transmission process association table 3, and the packet transfer processing function block specific data table 4, The packet transfer processing is performed by connecting and combining the packet transfer processing function blocks in a desired form.

  Here, examples of the packet transfer processing functional block include an Ethernet (registered trademark) processing block, a PoS processing block, an IP processing block, and an MPLS processing block.

  The reception processing association table 2 is reception processing person-in-charge information that defines a packet transfer processing functional block for executing reception processing of a packet based on the type of protocol to which the received packet belongs and the header or payload portion of the packet. There is a table that defines information used to determine which packet transfer processing function block to perform next after performing packet reception processing in a certain packet transfer processing function block. FIG. 2 shows a configuration example of the reception processing correlation table 2. In the reception processing correlation table 2, as shown in FIG. 2, the protocol and packet pattern are associated with the reception processing charge packet transfer processing function block ID specified corresponding to the protocol and packet pattern conditions. Stored.

  For example, if the protocol is MPLS and the packet pattern is label value = 1000, the corresponding ID corresponding to the reception processing packet transfer processing function block ID corresponding to 500 is stored in association with the corresponding ID.

  The transmission processing association table 3 stores next transmission processing charge information for designating a packet transfer processing functional block for executing the next packet transmission processing after the transmission processing in one packet transfer processing functional block among the plurality of packet transfer processing functional blocks. A table to be defined. FIG. 3 shows a configuration example of the transmission processing correlation table 3. In the transmission processing correlation table 3, the packet transfer processing function block ID and the next transmission processing charge packet transfer processing function block ID are stored in relation to each other. The packet transfer processing function block in charge of the next transmission processing is a packet transfer processing function block in charge of the next transfer processing of the packet when the packet transmission processing on the layer 1 is not completed by a certain packet transfer processing function block. .

  For example, the packet transmission processing function block ID corresponding to the next transmission processing corresponding to the packet transfer processing function block ID = 1 is 10, and the packet transmission processing function block ID corresponding to the next transmission processing corresponding to the packet transfer processing function block ID = 10 is 12. Are stored in association with each other.

  In this way, by defining the connection relationship between the packet transfer processing function blocks that perform packet transmission processing in the transmission processing correlation table 3, which packet transfer processing function block is transmitted next to a certain packet transfer processing function block. It is possible to specify in any combination what to do.

  The packet transfer processing function block specific data table 4 is a packet transfer processing function block specific data table for specifying parameter information necessary for packet transfer processing performed in each packet transfer processing function block, for example, an IPSec encryption key value. . FIG. 4 shows a configuration example of the packet transfer processing function block specific data table 4. The packet transfer processing function block unique data table 4 stores a packet transfer process function block ID, a protocol ID that is parameter information, and function block unique data as shown in FIG.

  The reception processing correlation table 2, the transmission processing correlation table 3, and the packet transfer processing function block specific data table 4 described above are stored in a memory provided in the packet transfer apparatus.

  FIG. 5 is a configuration example of a common header added when packet data is transferred between packet transfer processing functional blocks. This common header is used only for transfer between packet transfer processing functional blocks in the arithmetic processing unit 1.

  As the common header information, for example, as shown in FIG. 5, the Next Hop IP address, protocol, TTL (Time To Live, lifetime value), DiffServ (Differential Services, Diffserv) necessary for IP protocol processing is stored. Has been.

  In this way, the common header given to the packet indicates the protocol, TTL value, DiffServ, Next Hop IP address information necessary for the IP protocol processing. With this process, it becomes possible to perform the transmission process without being aware of the internal structure of the packet data to be transmitted.

  Next, the operation of the packet transfer apparatus configured as described above will be described. First, the reception processing operation will be described.

(Process 1)
In the arithmetic processing unit 1, when a packet is received from the layer 1, which condition among the conditions indicated in the protocol and the packet pattern stored in the reception processing association table 3 shown in FIG. To check. If a corresponding condition is found in the reception processing association table 3, the reception processing charge packet transfer processing function block ID corresponding to the condition specified in the reception processing association table 3 (herein referred to as ID1). To decide to perform reception processing of the received packet. At this time, a common header having the format shown in FIG. 5 is added to the received packet.

  In this way, at the time of reception processing of a received packet, which packet transfer processing functional block is to be processed is determined based on the information in the reception processing association table 3. This determination depends only on the data content of the received packet.

  As a result, for the packet reception processing, the connection relationship between the packet transfer processing function blocks, that is, the reception processing of another packet transfer processing function block after the reception processing of one packet transfer processing function block is performed. It is possible to perform reception processing by combining arbitrary packet transfer processing function blocks in a form according to the contents of the received packet without explicitly designating.

(Process 2)
The packet transfer processing functional block with ID = ID1 is a packet transfer processing functional block specific data table 4 using ID1 as a key to perform reception processing of the received packet with the packet transfer processing functional block with ID = ID1. Search for. In the packet transfer processing function block with the packet transfer processing function block ID = ID1, reception processing is performed using the parameter values shown in the packet transfer processing function block specific data table 4.

  Then, the packet data obtained as a result is checked which of the conditions specified in the protocol and packet pattern specified in the reception processing association table 3 is satisfied. If a corresponding condition is found, it is determined to perform reception processing of the received packet with the reception processing charge packet transfer processing function block ID (ID2) specified in the reception processing association table 3. At this time, a common header having the format shown in FIG. 5 is added to the received packet. In the reception process, the transfer destination protocol is input as the protocol of the common header.

  Further, the above-described processing 2 is repeated until it is determined that all reception processing in the received packet is finished and transmission processing is started.

  Here, in the packet transfer processing function block that has performed final reception processing, the packet transfer processing function block ID for performing transmission processing, that is, the packet transmission destination is determined in the reception processing. Each packet transfer processing function block has a function of determining a transmission destination of a packet when starting transmission processing when the packet transfer processing block itself is a final reception processing block.

  For example, the IP processing block has a function of searching a forwarding table of an IP packet and determining a destination interface in advance when the IP processing block is the final reception processing block. As a result, when the packet transfer processing function block that has performed final reception processing is an IP processing block, the IP processing block searches a forwarding table to determine a destination interface, and a packet that is a destination Determine the transfer processing functional block.

  Next, the transmission processing operation will be described.

(Process 3)
When the ID of the packet transfer processing function block that performs transmission processing determined by the packet transfer processing function block that performed final reception processing is ID3, the packet transfer processing function block with ID = ID3 is a packet that performs transmission processing. Using the transfer processing function block ID (ID3) as a key, the packet transfer processing function block specific data table 4 shown in FIG. 4 is searched, and the parameter value shown in the packet transfer processing function block specific data table 4 is read. The packet transfer processing functional block with ID = ID3 uses this parameter value and information (protocol, TTL value, DiffServ value, Next Hop IP address) indicated in the common header given to the transmission target packet. Packet transfer processing is performed.

  In addition, as part of the transmission process, the common header given to the transmission target packet is also updated. Here, the protocol processed by the current packet transfer processing function block is input as the protocol of the common header.

  When transmission processing is performed on the packet layer 1 in the packet transfer processing functional block with ID = ID3, the transmission processing ends.

(Process 4)
If the transmission process on the layer 1 of the packet is not completed in the process 3 described above, the transmission process is performed with the packet transfer process function block ID in charge of the next transmission process. For example, in the process 3, the packet transfer processing functional block with ID = ID3 searches the transmission process correlation table 3 shown in FIG. 2 using ID3 as a key, and performs the next transmission process charge packet shown in the transmission process correlation table 3 In order to perform transmission processing with the transfer processing function block ID = ID4, the procedure of processing 3 is executed.

  That is, in the packet transfer processing function block of ID = ID4, the packet transfer processing function block specific data table 4 shown in FIG. 4 is searched using ID4 as a key, and the parameter value shown in the packet transfer processing function block specific data table 4 is set. read out. The packet transfer processing functional block of ID = ID4 uses this parameter value and information (protocol, TTL value, DiffServ value, Next Hop IP address) indicated in the common header given to the transmission target packet. Packet transfer processing is performed. In addition, as part of the transmission process, the common header given to the transmission target packet is also updated. Here, the protocol processed by the current packet transfer processing function block is input as the protocol of the common header.

  As described above, when the transmission process of the packet on the layer 1 is not completed in the process 3, by searching the transmission process relation table 3, the packet transfer process function block in charge of the next transmission process can be simply and smoothly. Transmission processing can be performed. Then, process 3 is repeated until the transmission process on the layer 1 of the packet is completed.

  As described above, in this packet transfer apparatus, at the time of reception processing of a received packet, which packet transfer processing functional block is to be processed is determined based on information in the reception processing association table 3. This determination depends only on the data content of the received packet.

  Therefore, for packet reception processing, the connection relationship between the packet transfer processing functional blocks, that is, the relationship in which packet transfer processing functional block performs the reception processing after performing the reception processing of a certain packet transfer processing functional block Can be determined uniquely in accordance with the contents of the received packet without explicitly specifying, and it is possible to perform reception processing by combining arbitrary packet transfer processing functional blocks. That is, it is possible to perform reception processing by hierarchizing the L2 protocol and the L3 protocol in any combination.

  In this packet transfer apparatus, the connection relationship between packet transfer processing function blocks that perform packet transmission processing, that is, to which packet transfer processing function block a packet transfer processing function block should transfer a packet next The relationship is defined in the transmission processing correlation table 3. Therefore, by searching the transmission processing correlation table 3, it is determined simply and smoothly which packet transfer processing functional block is to perform transmission processing next to a certain packet transfer processing functional block.

  Further, the connection relationship between the packet transfer processing functional blocks for performing the packet transmission processing defined in the transmission processing association table 3 can be specified in any combination. That is, it is possible to perform transmission processing by hierarchizing the L2 protocol and the L3 protocol in any combination.

  The connection relationship between the packet transfer processing function blocks defined in the transmission processing correlation table 3 can be freely changed and added by an application. Thereby, a protocol stack capable of various transmission processes can be created without changing the hardware of the packet transfer apparatus or the program itself.

  In addition, the common header given to the packet indicates the protocol, TTL value, DiffServ value, and Next Hop IP address information necessary for IP protocol processing. In the process, it is possible to perform the transmission process smoothly without being aware of the internal structure of the transmission target packet data.

  Thus, any connection between the packet transfer processing function blocks can be realized for the transmission processing.

  As described above, in this packet transfer apparatus, it is possible to realize a desired packet transfer process even in a packet using a plurality of protocols by combining packet transfer process functional blocks flexibly. Transfer processing with a high degree of freedom is possible.

  As described above, the packet transfer apparatus according to the present invention is useful in all industries that exchange information using packet communication.

It is the principal part block diagram which showed the peripheral part of the arithmetic processing part in the packet transmission apparatus concerning this invention. It is the block diagram which showed the example of 1 structure of the reception process correlation table of the packet transfer apparatus concerning this Embodiment. It is the block diagram which showed the example of 1 structure of the transmission process correlation table of the packet transfer apparatus concerning this Embodiment. It is the block diagram which showed the example of 1 structure of the packet transfer process functional block specific data table of the packet transfer apparatus concerning this Embodiment. It is a block diagram which shows one structural example of a common header provided when transferring packet data between packet transfer processing functional blocks.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arithmetic processing part 2 Reception process correlation table 3 Transmission process correlation table 4 Packet transfer process functional block specific data table

Claims (6)

A plurality of packet transfer processing means for executing transfer processing of packets received according to a protocol used in Layer 2 or Layer 3;
A memory that stores reception processing charge information that defines packet transfer processing means for executing the reception processing of the packet based on the type of protocol to which the received packet belongs and the header or payload portion of the packet;
With
When the packet transfer processing means receives the packet, the packet transfer processing means then performs a reception process on the received packet based on the protocol type of the packet, the header or payload portion of the packet, and the reception processing charge information. And a packet transfer processing means for executing the step.   The packet transfer processing unit performs packet transfer between the packet transfer processing units in the transfer processing unit in a state where a common header common to the plurality of types of packet transfer processing units is added to the received packet. The packet transfer apparatus according to claim 1, wherein:   The packet transfer apparatus according to claim 2, wherein the common header includes a packet protocol, a lifetime value, a differential serve, and a next hop IP address. A plurality of packet transfer processing means for executing transfer processing of packets received according to a protocol used in Layer 2 or Layer 3;
A memory storing next transmission processing charge information for designating a packet transfer processing means for executing a next packet transmission process after a transmission process in one of the plurality of packet transfer processing means;
With
The packet transfer processing unit, wherein the packet transfer processing unit executes a packet transmission process on the packet transmitted to the packet transfer processing unit based on the next transmission processing charge information.   The transfer processing unit transfers packets between the packet transfer processing units in the transfer processing unit in a state where a common header common to the plurality of types of packet transfer processing units is added to the received packet. The packet transfer apparatus according to claim 4.   6. The packet forwarding apparatus according to claim 5, wherein the common header includes a packet protocol, a lifetime value, a differential serve, and a next hop IP address.

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