JP2017050579A - Packet transfer device, packet transfer method and packet transfer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packet transfer device which allows for good transmission of a stream, while distributing the communication loads, in a configuration for outputting packets to a plurality of physical ports selectively, and to provide a packet transfer method and a packet transfer program.SOLUTION: A packet transfer device in a communication system transmitting a stream constituted of a plurality of packets includes a transmission processing section for outputting the packets selectively to a plurality of physical ports of the packet transfer device, and a monitoring section for monitoring the flow rate of the packets at each physical port. The transmission processing section determines a use port, i.e., the physical port that must be the output destination of the packet, on the basis of the flow rate monitored by the monitoring section, and fixes the output destination of other packets, in the stream to which the packet determined the output destination belongs, to the use port.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a packet transfer apparatus, a packet transfer method, and a packet transfer program, and more particularly to a packet transfer apparatus, a packet transfer method, and a packet transfer program in a communication system that transmits a stream composed of a plurality of packets.

  For example, Japanese Patent No. 5271876 (Patent Document 1) discloses the following network transfer device. That is, the network transfer device includes a bandwidth monitoring unit that monitors traffic for each physical port in a logical port in which a plurality of physical ports of the network transfer device are logically bundled, and a traffic volume of the monitored traffic. A distribution execution determination unit that determines whether or not a predetermined threshold for the bandwidth of the physical port is exceeded, a distribution execution unit that redistributes traffic of the physical port in the logical port, and each of the distribution after the distribution by the distribution execution unit A distribution result determining unit configured to determine whether the traffic volume of the physical port traffic is less than the predetermined threshold, wherein the distribution execution determining unit is configured such that the traffic volume of the monitored traffic exceeds the predetermined threshold And if it exceeds, the distribution execution unit Further, among the monitored traffic, the average bandwidth of the traffic is added in descending order of the bandwidth, and the total of the average bandwidth is a certain percentage of the total bandwidth of the traffic flowing through the logical port. Only the traffic when exceeding is selected as a distribution target, distribution is performed for each VLAN accommodated in the logical port, and the distribution result determination unit determines the traffic volume of the traffic of each physical port after distribution. If it is determined that the predetermined threshold value is exceeded, the sorting is performed again by the sorting execution unit.

Japanese Patent No. 5271876 Japanese Patent No. 5204807

  For example, in a packet transfer apparatus having a plurality of physical ports, when communication loads are concentrated on one physical port, it may be desired to distribute the communication loads.

  For example, in the packet transfer apparatus described in Patent Literature 1, when the traffic volume of the traffic to be monitored exceeds a predetermined threshold for the bandwidth of the physical port, the traffic of the physical port in the logical port is redistributed. .

  For example, when traffic is redistributed while a stream composed of a plurality of packets is being transmitted, the physical port through which the stream passes may be different before and after the traffic redistribution.

  For example, if traffic redistribution occurs when a different IP address is assigned to each physical port, the identity of the IP address of the stream transmission source cannot be ensured, and the stream transmission may not be performed well. is there.

  The present invention has been made to solve the above-described problems, and its object is to improve stream transmission while distributing communication load in a configuration in which packets are selectively output to a plurality of physical ports. A packet transfer apparatus, a packet transfer method, and a packet transfer program that can be performed.

  (1) In order to solve the above-described problem, a packet transfer apparatus according to an aspect of the present invention is a packet transfer apparatus in a communication system that transmits a stream composed of a plurality of packets, and the packet transfer apparatus transfers the packet to the packet transfer apparatus. A transmission processing unit that selectively outputs to a plurality of physical ports of the device; and a monitoring unit that monitors the flow rate of the packet in each physical port, wherein the transmission processing unit monitors the flow rate monitored by the monitoring unit The transmission port determines the use port that is the physical port to be the output destination of the packet, and the transmission processing unit uses the output destination of the other packet in the stream to which the packet to which the output destination is determined belongs. Secure to the port.

  (6) In order to solve the above-described problem, a packet transfer method according to an aspect of the present invention is a packet transfer method in a packet transfer apparatus in a communication system that transmits a stream composed of a plurality of packets. The transfer apparatus selectively outputs the packet to a plurality of physical ports of the packet, monitors the flow rate of the packet at each physical port, and the physical to be output to the packet based on the flow rate. Determining a used port which is a port, and fixing an output destination of another packet in the stream to which the packet to which the output destination is determined belong to the used port.

  (7) In order to solve the above problem, a packet transfer program according to an aspect of the present invention is a packet transfer program used in a packet transfer apparatus in a communication system for transmitting a stream composed of a plurality of packets, The packet transfer apparatus selectively outputs the packet to a plurality of its own physical ports, and monitors a flow rate of the packet at each physical port to a computer, and an output destination of the packet based on the flow rate A program for executing a step of determining a use port that is the physical port to be used and a step of fixing an output destination of another packet in the stream to which the packet to which the output destination is assigned belong to the use port It is.

  The present invention can be realized not only as a packet transfer apparatus including such a characteristic processing unit, but also as a semiconductor integrated circuit that realizes part or all of the packet transfer apparatus, or as a communication system including the packet transfer apparatus. Can be realized.

  According to the present invention, in a configuration in which packets are selectively output to a plurality of physical ports, stream transmission can be performed satisfactorily while communication load is distributed.

FIG. 1 is a diagram showing a configuration of a communication system according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a configuration of packets exchanged in the communication system according to the embodiment of the present invention. FIG. 3 is a diagram showing a configuration of the packet transfer apparatus in the communication system according to the embodiment of the present invention. FIG. 4 is a diagram showing an example of a flow entry table held in the storage unit in the packet transfer apparatus according to the embodiment of the present invention. FIG. 5 is a diagram showing a configuration of a WAN side packet transmission processing unit in the packet transfer apparatus according to the embodiment of the present invention. FIG. 6 is a flowchart defining an operation procedure when the packet transfer apparatus according to the embodiment of the present invention performs a packet transfer process.

  First, the contents of the embodiment of the present invention will be listed and described.

  (1) A packet transfer apparatus according to an embodiment of the present invention is a packet transfer apparatus in a communication system that transmits a stream composed of a plurality of packets, and the packet is transferred to a plurality of physical ports of the packet transfer apparatus. A transmission processing unit that selectively outputs a monitoring unit that monitors the flow rate of the packet at each physical port, and the transmission processing unit outputs the packet based on the flow rate monitored by the monitoring unit. The used port, which is the physical port to be the destination, is determined, and the transmission processing unit fixes the output destination of other packets in the stream to which the packet for which the output destination has been determined belong to the used port.

  As described above, the output destination of each packet belonging to the stream is fixed to the used port determined based on the packet flow rate, and the output destination of the stream is fixed to, for example, a physical port where the communication load is not concentrated. be able to. Thereby, for example, even when different IP addresses are assigned to each physical port, it is possible to ensure the identity of the IP address of the stream transmission source while distributing the communication load. Therefore, in a configuration in which packets are selectively output to a plurality of physical ports, stream transmission can be performed satisfactorily while the communication load is distributed.

  (2) Preferably, when the packet transfer apparatus receives a new packet that is a packet of the new stream, the transmission processing unit determines the port used for the new packet based on the flow rate.

  With such a configuration, the output destination of all the packets belonging to the stream can be fixed to the determined used port.

  (3) More preferably, the packet transfer apparatus further includes an information generation unit that generates and holds stream information indicating a correspondence relationship between the stream and the used port, and the transmission processing unit includes the packet transfer When the apparatus receives the packet, the stream information is referred to, and when the stream to which the received packet belongs is included in the stream information, the packet is output to the use port corresponding to the stream.

  With such a configuration, other packets in the stream received after determining the use port of a certain stream can be output to the use port by simple processing.

  (4) Preferably, the transmission processing unit preferentially uses the predetermined physical port as the use port, and determines that the use port is the other physical port when it is determined that the flow rate in the predetermined physical port is large. Change to port.

  With such a configuration, a specific physical port can be preferentially used, and communication of the physical port can be offloaded to another physical port when the flow rate is large.

  (5) Preferably, the transmission processing unit can set different physical ports as output destinations of the plurality of streams received in parallel from the same device.

  With such a configuration, in the packet transfer apparatus, the output destinations of a plurality of streams received in parallel from the same apparatus can be fixed to different physical ports, for example, depending on the type of stream. A communication path can be established.

  (6) A packet transfer method according to an embodiment of the present invention is a packet transfer method in a packet transfer apparatus in a communication system that transmits a stream composed of a plurality of packets, and the packet transfer apparatus Selectively outputting to a plurality of own physical ports, monitoring a flow rate of the packet at each physical port, and determining a use port which is the physical port to which the packet is to be output based on the flow rate And a step of fixing an output destination of another packet in the stream to which the packet to which the output destination is determined belongs to the use port.

  As described above, the output destination of each packet belonging to the stream is fixed to the used port determined based on the packet flow rate, and the output destination of the stream is fixed to, for example, a physical port where the communication load is not concentrated. be able to. Thereby, for example, even when different IP addresses are assigned to each physical port, it is possible to ensure the identity of the IP address of the stream transmission source while distributing the communication load. Therefore, in a configuration in which packets are selectively output to a plurality of physical ports, stream transmission can be performed satisfactorily while the communication load is distributed.

  (7) A packet transfer program according to an embodiment of the present invention is a packet transfer program used in a packet transfer apparatus in a communication system that transmits a stream composed of a plurality of packets, and the packet transfer apparatus includes: Selectively outputting packets to the plurality of physical ports of the self, monitoring a flow rate of the packets at each of the physical ports to a computer, and at the physical ports to be output destinations of the packets based on the flow rates A program for executing a step of determining a used port and a step of fixing an output destination of another packet in the stream to which the packet to which the output destination is determined belong to the used port.

  As described above, the output destination of each packet belonging to the stream is fixed to the used port determined based on the packet flow rate, and the output destination of the stream is fixed to, for example, a physical port where the communication load is not concentrated. be able to. Thereby, for example, even when different IP addresses are assigned to each physical port, it is possible to ensure the identity of the IP address of the stream transmission source while distributing the communication load. Therefore, in a configuration in which packets are selectively output to a plurality of physical ports, stream transmission can be performed satisfactorily while the communication load is distributed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. Moreover, you may combine arbitrarily at least one part of embodiment described below.

[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a communication system according to an embodiment of the present invention.

  Referring to FIG. 1, the communication system 301 includes computers 121A and 121B, a packet transfer apparatus 101, and a server 151.

  Hereinafter, each of the computers 121A and 121B is also referred to as a computer 121. In FIG. 1, two computers 121 are representatively shown, but a larger or smaller number of computers 121 may be provided. Although one server 151 is representatively shown, a plurality of servers 151 may be provided.

  The communication system 301 transmits a stream composed of a plurality of packets. The stream is composed of, for example, a plurality of packets in which collected data is divided and stored. Specifically, the stream is composed of a plurality of packets exchanged in a state where a connection is established, such as a TCP session. For example, in the case of Internet access, a stream is composed of a plurality of packets exchanged in units of one Internet access.

  The packet transfer apparatus 101 transfers a stream exchanged between, for example, a LAN (Local Area Network) 10 and the Internet 11.

  More specifically, the packet transfer apparatus 101 is, for example, a home gateway apparatus, and transfers a plurality of packets constituting a stream. The packet transfer apparatus 101 transfers a packet in accordance with, for example, the TCP / IP standard and the UDP / IP standard.

[Outline of LAN10]
The packet transfer apparatus 101 exchanges packets with the computer 121 using, for example, one communication medium, specifically, a communication medium conforming to the Ethernet (registered trademark) standard. Note that the packet transfer apparatus 101 may exchange packets with the computer 121 using two or more communication media.

  The packet transfer apparatus 101 has, for example, an IP address GLI and a MAC address GLM as an IP address and a MAC (Media Access Control) address on the LAN 10 side. Specific values of the IP address GLI and the MAC address GLM are, for example, 192.168.1.1 and AA-AA-00-00-00-01, respectively.

  The computer 121A has, for example, an IP address CLI1 and a MAC address CLM1 as an IP address and a MAC address. Specific values of the IP address CLI1 and the MAC address CLM1 are, for example, 192.168.1.2 and BB-BB-00-00-00-01, respectively.

  The computer 121B has, for example, an IP address CLI2 and a MAC address CLM2 as an IP address and a MAC address. Specific values of the IP address CLI2 and the MAC address CLM2 are, for example, 192.168.1.3 and EE-EE-00-00-00-01, respectively.

[Outline of Internet 11]
For example, the packet transfer apparatus 101 exchanges packets with the server 151 using a plurality of communication media on the Internet 11 side. More specifically, for example, the packet transfer apparatus 101 exchanges packets with the server 151 using two communication media according to the TCP / IP standard.

  Here, the two communication media are, for example, optical media and communication media complying with LTE (Long Term Evolution) standards. The communication speed of the optical line is 1 Gbps, for example. Further, the communication speed of communication media according to the LTE standard is, for example, 10 Mbps.

  Note that the packet transfer apparatus 101 may exchange packets with the server 151 using three or more communication media. Further, the communication medium is not limited to the communication medium according to the optical line and the LTE (Long Term Evolution) standard, and may be a communication medium according to another standard such as W-CDMA and CDMA2000.

  The packet transfer apparatus 101 has, for example, an IP address GWI1 and a MAC address GWM1 as an IP address for an optical line on the Internet 11 side (hereinafter also referred to as an optical line IP address) and a MAC address. Specific values of the IP address GWI1 and the MAC address GWM1 are, for example, 10.1.1.1 and DD-DD-00-00-00-01, respectively.

  Also, the packet transfer apparatus 101 has, for example, an IP address GWI2 and a MAC address GWM2 as communication media IP addresses (hereinafter also referred to as LTE_IP addresses) and MAC addresses according to the LTE standard on the Internet 11 side. Specific values of the IP address GWI2 and the MAC address GWM2 are, for example, 200.1.1.1 and FF-FF-00-00-00-01, respectively.

  The server 151 has, for example, an IP address SWI and a MAC address SWM as an IP address and a MAC address. Specific values of the IP address SWI and the MAC address SWM are, for example, 1.1.1.1 and CC-CC-00-00-00-01, respectively.

[Packet configuration]
FIG. 2 is a diagram showing an example of a configuration of packets exchanged in the communication system according to the embodiment of the present invention.

  FIG. 2 shows an example of a packet transmitted in accordance with the TCP / IP standard in the communication system 301. Referring to FIG. 2, packet 401 includes a MAC header, an IP header, a TCP header, and a payload. In the communication system 301, a packet transmitted according to the UDP / IP standard includes a UDP header instead of a TCP header.

  In the frame 401, a MAC header, an IP header, a TCP header, and a payload are located in order from the top. Hereinafter, the packet 401 is also referred to as a MAC frame 401. In the packet 401, a part composed of an IP header, a TCP header, and a payload is also referred to as an IP packet 402.

  The MAC header stores a source MAC address and a destination MAC address. Hereinafter, each of the transmission source MAC address and the transmission destination MAC address is also referred to as MAC_SA and MAC_DA.

  The IP header stores a source IP address and a destination IP address. Hereinafter, each of the transmission source IP address and the transmission destination IP address is also referred to as IP_SA and IP_DA.

  The TCP header stores a transmission source port number and a transmission destination port number. Hereinafter, each of the transmission source port number and the transmission destination port number is also referred to as L4_SP and L4_DP.

[Web information stream A and mail stream C]
Referring to FIG. 1 again, for example, in computer 121A, mail application C for sending and receiving electronic mail and browser application A for displaying a web browser are operating. For example, port numbers 2000 and 3000 are assigned to the mail application C and the browser application A, for example, by the OS (Operation System) of the computer 121A.

  For example, when the mail application C transmits data indicating the contents of an electronic mail, a stream (hereinafter also referred to as a mail stream C) composed of packets in which the data is divided and stored is transmitted from the computer 121A. The data is transmitted to the mail server program for transferring and delivering the electronic mail in the server 151 via the transfer device 101. For example, the mail server program is assigned a port number of 1000 by the OS of the server 151.

  At the timing when the packet transfer apparatus 101 receives the mail stream C, each packet 401 constituting the mail stream C stores the following addresses.

  That is, GLM and CLM1 are stored in the MAC header of the packet 401 as MAC_DA and MAC_SA, respectively. In the IP header of the packet 401, SWI and CLI1 are stored as IP_DA and IP_SA, respectively. The TCP header in the packet 401 stores numbers 1000 and 2000 as L4_DP and L4_SP, respectively.

  For example, when the browser application A uploads data used to display a web page, a stream (hereinafter also referred to as a web information stream A) composed of packets in which the data is divided and stored is stored in the computer. 121A is transmitted to the web server program for processing related to data used for displaying the web page in the server 151 via the packet transfer apparatus 101. For example, a 4000 port number is assigned to the web server program by the OS of the server 151.

  At the timing when the packet transfer apparatus 101 receives the web information stream A, each packet 401 constituting the web information stream A stores the following addresses.

  That is, GLM and CLM1 are stored in the MAC header of the packet 401 as MAC_DA and MAC_SA, respectively. In the IP header of the packet 401, SWI and CLI1 are stored as IP_DA and IP_SA, respectively. In the TCP header of the packet 401, numbers 4000 and 3000 are stored as L4_DP and L4_SP, respectively.

[Mail stream B]
For example, in the computer 121B, a mail application B for sending and receiving electronic mail is operating. For example, the port number 2000 is assigned to the mail application B by the OS of the computer 121A, for example.

  For example, when the mail application B requests transmission of an e-mail addressed to itself, a stream (hereinafter also referred to as mail stream B) composed of packets in which data indicating the request is divided and stored is stored in the computer. 121B is transmitted to the mail server program in the server 151 via the packet transfer apparatus 101.

  At the timing when the packet transfer apparatus 101 receives the mail stream B, each packet 401 constituting the mail stream B stores the following addresses.

  That is, GLM and CLM2 are stored in the MAC header of the packet 401 as MAC_DA and MAC_SA, respectively. In the IP header of the packet 401, SWI and CLI2 are stored as IP_DA and IP_SA, respectively. The TCP header in the packet 401 stores numbers 1000 and 2000 as L4_DP and L4_SP, respectively.

[Configuration of packet transfer device]
FIG. 3 is a diagram showing a configuration of the packet transfer apparatus in the communication system according to the embodiment of the present invention.

  With reference to FIG. 3, the packet transfer apparatus 101 includes a LAN side port 21, a LAN side packet receiving unit 22, a LAN side packet transmitting unit 23, a flow rate monitoring unit 24, a WAN side packet transmission processing unit 25, A WAN-side packet receiving unit 26, a storage unit 27, WAN-side ports 28A and 28B, a stream information creating unit 29, a counter 30, and a routing table creating unit 31 are provided.

  Hereinafter, each of the WAN side ports 28 </ b> A and 28 </ b> B is also referred to as a WAN side port 28. In FIG. 3, two WAN side ports 28 are representatively shown, but a larger number of WAN side ports 28 may be provided. In addition, although one LAN side port 21 is representatively shown, a plurality of LAN side ports 21 may be provided.

  The LAN-side port 21 is a physical port for connecting to the LAN 10 that is connected to a communication medium according to the Ethernet standard, for example. The logical port name of the LAN side port 21 is, for example, “LAN1”.

  The WAN side port 28A is a physical port for connecting to the Internet 11 connected to an optical line, for example. The logical port name of the WAN side port 28A is, for example, “WAN1”.

  The WAN-side port 28B is a physical port for connecting to the Internet 11 that is connected to a communication medium according to the LTE standard, for example. The logical port name of the WAN side port 28B is, for example, “WAN2”.

  The counter 30 counts clock pulses generated by, for example, an oscillation circuit using a crystal resonator, and holds the counted value.

  FIG. 4 is a diagram showing an example of a flow entry table held in the storage unit in the packet transfer apparatus according to the embodiment of the present invention.

  Referring to FIG. 4, storage unit 27 holds, for example, flow entry table FETbl received from stream information creation unit 29. For example, flow entries FE1 to FE3 are registered in the flow entry table FETbl. Details of the flow entry table FETbl will be described later.

  Referring to FIG. 3 again, the routing table creation unit 31 creates a routing table, for example, and stores the created routing table in the storage unit 27. The routing table creation unit 31 creates a routing table in accordance with, for example, a user input. Note that the routing table creation unit 31 may automatically create a routing table using a RIP (Routing Information Protocol) or the like.

  The routing table includes, for example, a correspondence relationship between a destination IP address, an interface IP address, and a gateway IP address.

  Here, the destination IP address is generated based on, for example, the IP_DA and subnet mask of the IP packet 402 to be transferred. The interface IP address is, for example, the IP address GWI1 for the optical line on the Internet 11 side, the IP address GWI2 for communication media according to the LTE standard on the Internet 11 side, or the IP address GLI on the LAN 10 side. The gateway IP address is, for example, the IP address of the device where the IP packet 402 ends. The gateway IP address may be the IP address of the gateway device to be transferred next.

  Specifically, the correspondence relationship between the destination IP address, the interface IP address, and the gateway IP address is specifically the relationship between SWI, GWI1, and SWI, the relationship between SWI, GWI2, and SWI, the relationship between CLI1, GLI, and CLI1, And the relationship between CLI2, GLI, and CLI2.

  The LAN side packet receiving unit 22 receives the MAC frame 401 from the computer 121 via, for example, the LAN side port 21.

  More specifically, for example, the LAN side packet receiving unit 22 is assigned a GLM as a MAC address, and receives a MAC frame 401 from the computer 121 via the LAN 10, whether or not the received MAC frame 401 is addressed to itself. To check. At this time, the LAN side packet receiving unit 22 confirms whether or not the received MAC frame 401 is addressed to itself based on, for example, whether or not MAC_DA stored in the MAC header is GLM.

  For example, when the LAN side packet receiving unit 22 confirms that the received MAC frame 401 is addressed to itself, the LAN side packet receiving unit 22 acquires the IP packet 402 included in the MAC frame 401 and uses the acquired IP packet 402 as the WAN side packet. The data is output to the transmission processing unit 25. For example, when the LAN side packet receiving unit 22 confirms that the received MAC frame 401 is not addressed to itself, the LAN side packet receiving unit 22 discards the MAC frame 401.

[Configuration of WAN side packet transmission processing unit]
FIG. 5 is a diagram showing a configuration of a WAN side packet transmission processing unit in the packet transfer apparatus according to the embodiment of the present invention.

  Referring to FIG. 5, WAN side packet transmission processing unit 25 includes a used port searching unit 41, a routing table searching unit 42, a used port determining unit 43, a transmitting unit 44, and an address converting unit 45.

  The WAN side packet transmission processing unit 25 selectively outputs the packet to a plurality of physical ports of the own packet transfer apparatus 101.

  The WAN-side packet transmission processing unit 25 determines a use port that is a physical port to be a packet output destination based on the packet flow rate monitored by the flow rate monitoring unit 24.

[Transfer processing of web information stream A]
Hereinafter, when the packet transfer apparatus 101 is not transmitting / receiving a stream and the flow entry FE1 to FE3 is not registered in the flow entry table FETbl held in the storage unit 27 unlike FIG. Assume that the apparatus 101 newly receives the web information stream A from the computer 121A.

[Processing of new packet of Web information stream A]
For example, the WAN side packet transmission processing unit 25 selectively outputs the IP packet 402 to the WAN side port 28A or 28B.

  More specifically, for example, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 from the LAN side packet receiving unit 22, the received IP packet 402 receives IP_DA, IP_SA, L4_DP, and L4_SP , SWI, CLI1, 4000 and 3000, respectively.

  When the used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27 and confirms that no flow entry is registered, the IP packet 402 received from the LAN side packet receiving unit 22 is The packet is recognized as a new stream packet (hereinafter also referred to as a new packet A).

  For example, the used port search unit 41 outputs the new packet A to the routing table search unit 42. In addition, the used port search unit 41 outputs, for example, new packet reception information indicating that a new packet has been received, to the used port determination unit 43 together with the new packet A.

  For example, when receiving the new packet A from the used port search unit 41, the routing table search unit 42 acquires IP_DA, that is, SWI from the received new packet A.

  The routing table search unit 42 acquires the relationship between SWI, GWI1, and SWI and the relationship between SWI, GWI2, and SWI related to SWI by referring to the routing table held in the storage unit 27, for example. The acquired two relationships are output to the address conversion unit 45.

  For example, when the own packet transfer apparatus 101 receives a new packet that is a packet of a new stream, the used port determination unit 43 determines a used port of the new packet based on the packet flow rate.

  Specifically, for example, when the used port determining unit 43 receives new packet reception information and a new packet A from the used port searching unit 41, the used port determining unit 43 recognizes that its own packet transfer apparatus 101 has received a new packet.

  Then, based on the packet flow rate monitored by the flow rate monitoring unit 24, the used port determining unit 43 determines the used port, which is the physical port that should be the output destination of the packet, as either the WAN side port 28A or 28B. To do.

  For example, the used port determination unit 43 includes a packet flow rate A indicating the number of packets transmitted / received in the WAN side port 28A per unit time and a packet flow rate indicating the number of packets transmitted / received in the WAN side port 28B per unit time. B is received from the flow rate monitoring unit 24 every predetermined time Tf.

  As described above, since it is assumed that the packet transfer apparatus 101 is not transmitting / receiving a stream, both the packet flow rate A and the packet flow rate B received by the used port determination unit 43 from the flow rate monitoring unit 24 are zero.

  For example, the used port determining unit 43 preferentially sets a predetermined physical port as a used port, and changes the used port to another physical port when determining that the packet flow rate in the predetermined physical port is large.

  Specifically, the used port determination unit 43 preferentially uses the WAN side port 28A as a used port, for example, when the flow rate in the WAN side port 28A, that is, the packet flow rate A is equal to or higher than a predetermined threshold Thp. The port is changed from the WAN side port 28A to the WAN side port 28B.

  For example, when the used port determining unit 43 recognizes that its own packet transfer apparatus 101 has received a new packet, it checks the latest packet flow rate A and packet flow rate B received from the flow rate monitoring unit 24.

  For example, since the latest packet flow rate A is zero, the use port determination unit 43 confirms that the use port determination unit 43 is smaller than the threshold Thp, and determines the WAN side port 28A as the use port. The used port determination unit 43 outputs, for example, “WAN1”, which is the logical port name of the determined WAN side port 28A, and the new packet A to the address conversion unit 45.

  The address conversion unit 45 performs, for example, a NAPT (Network Address Port Translation) process for sharing a global IP address on the Internet 11 side among a plurality of applications for an IP packet 402 in the upstream direction from the LAN 10 side to the Internet 11 side. .

  More specifically, for example, the address conversion unit 45 converts the IP_SA and L4_SP included in the IP packet 402 received from the computer 121 into optical port IP addresses or LTE_IP addresses and port numbers corresponding to IP_SA and L4_SP (hereinafter, corresponding port numbers). Respectively).

  Specifically, the address conversion unit 45 receives, for example, the relationship between SWI, GWI1, and SWI and the relationship between SWI, GWI2, and SWI from the routing table search unit 42, and “WAN1” and When a new packet A is received, the following processing is performed.

  That is, for example, the address conversion unit 45 creates original header information indicating the contents of the IP header and the TCP header included in the new packet A, and outputs the created original header information to the stream information creation unit 29.

  Further, the address conversion unit 45 recognizes that the relationship between SWI, GWI1, and SWI should be used based on “WAN1”, for example.

  The address conversion unit 45 rewrites IP_SA and L4_SP included in the new packet A based on, for example, the relationship between SWI, GWI1, and SWI.

  Specifically, the address translation unit 45 rewrites IP_SA included in the new packet A from CLI1 to GWI1. The address conversion unit 45 rewrites L4_SP included in the new packet A to 3024. Here, 3024 is a corresponding port number corresponding to CLI1 and 3000.

  For example, the address translation unit 45 creates and creates post-rewrite header information indicating the contents of the IP header and the TCP header included in a new packet A (hereinafter also referred to as a new packet A after rewriting) in which IP_SA and L4_SP are rewritten. The rewritten header information is output to the stream information creation unit 29 together with the logical port name “WAN1”.

  The address conversion unit 45 outputs, for example, the logical port name “WAN1” and the new packet A after rewriting to the transmission unit 44.

[Create stream information]
Referring to FIGS. 3 and 4 again, the stream information creation unit 29 creates, for example, stream information indicating a correspondence relationship between a stream and a used port, and stores the created stream information in the storage unit 27.

  Specifically, the stream information creation unit 29 uses the original header information, the rewritten header information, and the logical port name “WAN1” received from the address conversion unit 45, for example, to generate the flow entry FE1 shown in FIG. Create and register in the flow entry table FETbl. The registered flow entry is the stream information indicating the correspondence between the stream and the used port.

  More specifically, the stream information creation unit 29 sets each item in the “upstream” direction, for example. The stream information creation unit 29 sets “WAN1” as the “transmission logical port name” based on “WAN1” that is the logical port name received from the address conversion unit 45, for example. Further, for example, since the physical port on the LAN 10 side is only the LAN side port 21, the stream information creation unit 29 sets “LAN1” as the “reception logical port name”.

  For example, the stream information creation unit 29 sets “SWI, CLI1” as “reception side IP_DA, IP_SA” based on the content of the IP header indicated by the original header information. Also, the stream information creation unit 29 sets “TCP” and “4000, 3000” as “reception side protocol” and “reception side L4_DP, L4_SP” based on the contents of the TCP header indicated by the original header information, for example. Set.

  For example, the stream information creation unit 29 sets “SWI, GWI1” as “transmission side IP_DA, IP_SA” based on the content of the IP header indicated by the rewritten header information. Also, the stream information creation unit 29 sets “TCP” and “4000,3024” as “transmission side protocol” and “transmission side L4_DP, L4_SP” based on the contents of the TCP header indicated by the rewritten header information, for example. Set each.

  For example, the stream information creation unit 29 sets a predetermined “720” as the “age time”.

  For example, the reception source and transmission destination of the IP packet 402 (hereinafter also referred to as the downlink IP packet 402) in response to the IP packet 402 (hereinafter also referred to as the uplink IP packet 402) transmitted in the uplink direction is the uplink IP packet. For example, the stream information creation unit 29 sets each item in the “downward” direction based on the set item in the “upward” direction.

  Specifically, the stream information creation unit 29, for example, from the “reception logical port name” and “transmission logical port name” in the “upstream” direction to the “transmission logical port name” and “reception logical port” in the “downward” direction. “LAN1” and “WAN1” are set as names.

  The stream information creation unit 29, for example, based on the “reception side IP_DA, IP_SA” and the “transmission side IP_DA, IP_SA” in the “upstream” direction, respectively, “CLI1, SWI” and “GWI1, SWI” are set as “IP_DA, IP_SA”.

  The stream information creation unit 29 sets, for example, “TCP” as “transmission side protocol” and “reception side protocol” in the “downward” direction from “reception side protocol” and “transmission side protocol” in the “upward” direction, respectively. To do.

  The stream information creation unit 29, for example, based on “reception side L4_DP, L4_SP” and “transmission side L4_DP, L4_SP” in the “upstream” direction, and “transmission side L4_DP, L4_SP” and “reception side” in the “downward” direction, respectively. As “L4_DP, L4_SP”, “3000, 4000” and “3024, 4000” are set.

  For example, the stream information creation unit 29 sets “720” as the “age time” in the same manner as the “upward” direction.

  For example, when the registration of the created flow entry FE1 in the flow entry table FETbl is completed, the stream information creation unit 29 manages the lifetime of the registered flow entry FE1.

  Specifically, for example, the stream information creation unit 29 acquires the count value from the counter 30 at the timing when the flow entry FE1 is registered, sets the acquired count value as the start timing, and monitors the count value in the counter 30. To do.

  Then, for example, the stream information creation unit 29 monitors the access to the flow entry FE1 by the WAN side packet transmission processing unit 25 and the WAN side packet reception unit 26, and sets “720” seconds as the “age time” from the start timing. If access to the flow entry FE1 occurs before the time elapses, the access timing is reset as a new start timing.

  For example, when access to the flow entry FE1 does not occur until “720” seconds elapse from the set or reset start timing, the stream information creation unit 29 deletes the flow entry FE1.

  For example, the transmission unit 44 counts the number of packets output to the WAN side port 28A or 28B, and holds transmission count values TCA and TCB which are the counted values. The transmitting unit 44 can also count the number of bytes of data output to the WAN side port 28A or 28B.

  Referring to FIG. 5 again, transmission unit 44 has an L2 switch function, for example, and receives logical port name “WAN1” and new packet A after rewriting from address conversion unit 45. Based on the logical port name “WAN1”, it recognizes that the received new rewritten packet A should be transmitted to the Internet 11 side via the WAN side port 28A.

  Then, the transmission unit 44 creates a MAC frame 401 including the new packet A after rewriting, for example. At this time, for example, the transmission unit 44 sets SWM and GWM1 as MAC_DA and MAC_SA in the MAC header based on the correspondence table between the MAC address and the IP address created using, for example, ARP (Address Resolution Protocol). include.

  For example, the transmission unit 44 transmits the created MAC frame 401 to the Internet 11 side via the WAN side port 28A, and increments the transmission count value TCA.

[Processing of subsequent packet of Web information stream A]
The WAN-side packet transmission processing unit 25 fixes the output destination of other packets in the stream to which the packet whose output destination has been determined belongs to the determined used port. For example, the WAN side packet transmission processing unit 25 fixes the output destination of other packets in the stream to which the packet whose output destination has been determined to the determined use port regardless of the packet flow rate after the use port is determined.

  More specifically, for example, when the packet transfer apparatus 101 of the WAN side receives the packet, the WAN side packet transmission processing unit 25 refers to the stream information, and if the stream to which the received packet belongs is included in the stream information, The received packet is output to the use port corresponding to the stream.

  Hereinafter, it is assumed that the packet transfer apparatus 101 newly receives an IP packet 402 subsequent to the new packet A.

  For example, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 following the new packet A from the LAN side packet receiving unit 22, the IP_DA, IP_SA, L4_DP, L4_SP from the received IP packet 402. As SWI, CLI1, 4000 and 3000, respectively.

  The used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27, and the acquired SWI, CLI1, and 4000 and 3000 are the "receiving side" in the "up" direction in the flow entry FE1. IP_DA, IP_SA ”and“ receiving side L4_DP, L4_SP ”are confirmed to be included, and the IP packet 402 received from the LAN side packet receiving unit 22 is recognized as the subsequent packet A.

  The used port search unit 41 outputs, for example, subsequent packet reception information indicating that the subsequent packet A has been received and that the flow entry FE1 should be referenced to the address conversion unit 45 together with the subsequent packet A.

  For example, when receiving the subsequent packet reception information and the subsequent packet A from the used port search unit 41, the address conversion unit 45 recognizes that the subsequent packet A has been received based on the received subsequent packet reception information, and receives the subsequent packet. The following processing is performed with reference to the flow entry FE1 indicated by the information.

  That is, for example, the address translation unit 45 rewrites IP_SA and L4_SP included in the subsequent packet A in the same manner as the new packet A based on the content of the flow entry FE1.

  For example, the address translation unit 45 transmits a subsequent packet A in which IP_SA and L4_SP are rewritten (hereinafter also referred to as a subsequent packet A after rewriting) together with “WAN1” that is a “transmission logical port name” in the “upstream” direction. 44.

  When the transmission unit 44 receives, for example, the logical port name “WAN1” and the rewritten subsequent packet A from the address conversion unit 45, the transmission unit 44 receives the rewritten subsequent port based on the received logical port name “WAN1”. It is recognized that the packet A should be transmitted to the Internet 11 side via the WAN side port 28A.

  Then, for example, the transmitting unit 44 transmits the rewritten subsequent packet A to the Internet 11 side via the WAN side port 28A and increments the transmission count value TCA.

  The packet transfer apparatus 101 performs the same processing every time it receives the IP packet 402 that constitutes the web information stream A. In this way, the web information stream A is transmitted from the computer 121A to the server 151 via the LAN side port 21 and the WAN side port 28A in the packet transfer apparatus 101 in the communication system 301.

[Web Information Stream AR]
Referring to FIG. 1 again, for example, when the server 151 receives the web information stream A from the packet transfer apparatus 101, the server 151 creates a web information stream AR that is a response stream of the received web information stream A, and creates the created web The information stream AR is transmitted to the packet transfer apparatus 101.

  More specifically, for example, the server 151 sets and transmits IP_DA, IP_SA, L4_DP, and L4_SP of each IP packet 402 constituting the web information stream AR in GWI1, SWI, 3024, and 4000, respectively.

  Referring to FIG. 3 again, the WAN side packet receiving unit 26 in the packet transfer apparatus 101 counts, for example, the number of packets received from the WAN side ports 28A and 28B, respectively, and the received count value RCA which is each counted value. , Hold RCB. The WAN side packet receiving unit 26 can also count the number of bytes of data received from the WAN side port 28A or 28B.

  For example, when the WAN side packet receiving unit 26 receives the IP packet 402 constituting the web information stream AR from the server 151 via the WAN side port 28A, the WAN side packet receiving unit 26 increments the reception count value RCA and is held in the storage unit 27. The following processing is performed with reference to the flow entry table FETbl.

  That is, the WAN side packet receiving unit 26 acquires, for example, IP_DA, IP_SA and L4_DP, L4_SP from the received IP packet 402, and based on the acquired IP address and port number, the flow entry corresponding to the received IP packet 402 Is confirmed to be FE1.

  Then, the WAN side packet receiving unit 26 rewrites IP_DA and L4_DP of the received IP packet 402 to CLI1 and 3000, respectively, based on each item in the “downward” direction of the flow entry FE1, for example.

  For example, the WAN side packet receiving unit 26 outputs the IP packet 402 in which IP_DA and L4_DP are rewritten to the LAN side packet transmitting unit 23.

  For example, when receiving the IP packet 402 from the WAN side packet receiving unit 26, the LAN side packet transmitting unit 23 transmits the received IP packet 402 to the computer 121A indicated by the IP address CLI1 via the LAN side port 21.

  The packet transfer apparatus 101 performs the same processing every time it receives the IP packet 402 that constitutes the web information stream AR. In this way, the web information stream AR is transmitted from the server 151 to the computer 121A via the WAN side port 28A and the LAN side port 21 in the packet transfer apparatus 101 in the communication system 301.

[Details of packet flow rate]
The flow rate monitoring unit 24 monitors the flow rate of packets at each physical port. Specifically, the flow rate monitoring unit 24 monitors the packet flow rate A and the packet flow rate B, for example.

  More specifically, the flow rate monitoring unit 24 transmits the transmission count values TCA and TCB and the reception count values RCA and RCB to the transmission unit 44 and the WAN side packet reception unit in the WAN side packet transmission processing unit 25, for example, at every predetermined time Tf. 26 respectively.

  For example, the flow rate monitoring unit 24 calculates the increment of the transmission count value TCA and the reception count value RCA per predetermined time Tf, and calculates the packet flow rate A by dividing the sum of the calculated increments by the predetermined time Tf. .

  Similarly, the flow rate monitoring unit 24 calculates, for example, each increment of the transmission count value TCB and the reception count value RCB per predetermined time Tf, and divides the sum of the calculated increments by the predetermined time Tf to thereby calculate the packet flow rate B Is calculated.

  The flow rate monitoring unit 24 outputs, for example, the calculated packet flow rate A and packet flow rate B to the use port determining unit 43 in the WAN side packet transmission processing unit 25 every predetermined time Tf.

  Note that the flow rate of packets in each physical port is not limited to the configuration of the number of packets transmitted / received in the WAN side port 28 per unit time, but the amount of data transmitted / received in the WAN side port 28 per unit time, for example, the number of bytes It may be.

[Mail stream B transfer processing]
Hereinafter, when the packet transfer apparatus 101 transmits / receives the web information streams A and AR and the flow entry FE1 is registered in the flow entry table FETbl held in the storage unit 27, unlike FIG. Assume that the packet transfer apparatus 101 newly receives the mail stream B from the computer 121B.

  The transfer process of the mail stream B is the same as the transfer process of the web information stream A described above, and will be briefly described below.

[Process new packet of mail stream B]
Referring to FIGS. 3 and 5 again, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 from the LAN side packet receiving unit 22, for example, the received IP packet 402 receives the IP_DA, As IP_SA, L4_DP, and L4_SP, SWI, CLI2, 1000, and 2000 are acquired.

  The used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27, and receives the IP received from the LAN side packet receiving unit 22 based on the acquired SWI, CLI2, 1000, 2000 It is confirmed that the flow entry corresponding to the packet 402 is not registered. Then, the used port search unit 41 recognizes that the IP packet 402 is a new packet B, for example.

  For example, the used port search unit 41 outputs the new packet B to the routing table search unit 42. In addition, the used port search unit 41 outputs the new packet reception information to the used port determination unit 43 together with the new packet B, for example.

  For example, when the routing table search unit 42 receives a new packet B from the used port search unit 41, based on the contents of the IP header of the received new packet B, the relationship between SWI, GWI1, and SWI, and SWI, GWI2, and SWI. Is acquired from the storage unit 27, and the acquired two relationships are output to the address conversion unit 45.

  For example, when the used port determining unit 43 receives new packet reception information and new packet B from the used port searching unit 41, the used port determining unit 43 checks the latest packet flow rate A and packet flow rate B received from the flow rate monitoring unit 24.

  For example, the used port determining unit 43 confirms that the latest packet flow rate A is smaller than the threshold Thp, and determines the WAN side port 28A as the used port. The used port determination unit 43 outputs, for example, “WAN1”, which is the logical port name of the determined WAN side port 28A, and the new packet B to the address conversion unit 45.

  The address conversion unit 45 receives, for example, the relationship between SWI, GWI1, and SWI and the relationship between SWI, GWI2, and SWI from the routing table search unit 42, and receives “WAN1” and the new packet B from the used port determination unit 43. The following processing is performed.

  That is, for example, the address conversion unit 45 creates original header information indicating the contents of the IP header and the TCP header included in the new packet B, and outputs the created original header information to the stream information creation unit 29.

  For example, the address translation unit 45 recognizes that the relationship between SWI, GWI1, and SWI should be used based on “WAN1”, and changes the IP_SA included in the new packet B from CLI2 to GWI1 based on the relationship. rewrite.

  The address translation unit 45 rewrites L4_SP included in the new packet B to No. 2024. Here, 2024 is the corresponding port number corresponding to CLI2 and 2000.

  The address translation unit 45 creates, for example, header information after rewriting indicating the contents of the IP header and TCP header included in the new packet B (hereinafter also referred to as new packet B after rewriting) in which IP_SA and L4_SP are rewritten. The rewritten header information is output to the stream information creation unit 29 together with the logical port name “WAN1”.

  Further, the address conversion unit 45 outputs, for example, the logical port name “WAN1” and the rewritten new packet B to the transmission unit 44.

[Add Flow Entry]
The stream information creation unit 29 creates the flow entry FE2 shown in FIG. 4 by using the original header information, the header information after rewriting, and the logical port name “WAN1” received from the address translation unit 45, for example. It is additionally registered in the table FETbl.

  For example, when receiving the logical port name “WAN1” and the rewritten new packet B from the address converting unit 45, the transmitting unit 44 transmits the received new rewritten packet B to the Internet 11 side via the WAN side port 28A. At the same time, the transmission count value TCA is incremented.

[Processing of subsequent packets of mail stream B]
Hereinafter, it is assumed that the packet transfer apparatus 101 newly receives an IP packet 402 subsequent to the new packet B.

  For example, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 subsequent to the new packet B from the LAN side packet reception unit 22, the IP_DA, IP_SA, L4_DP, L4_SP from the received IP packet 402. As SWI, CLI2, 1000 and 2000 respectively.

  The used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27, and based on the acquired SWI, CLI2, 1000, 2000, and flow entry FE2, the LAN side packet receiving unit The IP packet 402 received from the network 22 is recognized as the subsequent packet B.

  The used port search unit 41 outputs, for example, subsequent packet reception information indicating that the subsequent packet B has been received and that the flow entry FE2 should be referenced to the address conversion unit 45 together with the subsequent packet B.

  For example, when receiving the subsequent packet reception information and the subsequent packet B from the use port search unit 41, the address conversion unit 45 refers to the flow entry FE2 indicated by the received subsequent packet reception information, and the IP_SA and L4_SP is rewritten in the same manner as the new packet B.

  For example, the address conversion unit 45 transmits a subsequent packet B (hereinafter also referred to as a subsequent packet B after rewriting) in which IP_SA and L4_SP are rewritten together with “WAN1” that is a “transmission logical port name” in the “uplink” direction. 44.

  For example, when receiving the logical port name “WAN1” and the rewritten subsequent packet B from the address converting unit 45, the transmitting unit 44 transmits the received rewritten subsequent packet B to the Internet 11 side via the WAN side port 28A. At the same time, the transmission count value TCA is incremented.

  The packet transfer apparatus 101 performs the same processing every time it receives the IP packet 402 that constitutes the mail stream B. In this way, the mail stream B is transmitted from the computer 121B to the server 151 via the LAN side port 21 and the WAN side port 28A in the packet transfer apparatus 101 in the communication system 301.

[Mail stream BR]
Referring to FIG. 1 again, for example, when receiving the mail stream B from the packet transfer apparatus 101, the server 151 creates a mail stream BR that is a response stream of the received mail stream B, and creates the created mail stream BR. Transmit to the packet transfer apparatus 101.

  More specifically, for example, the server 151 sets and transmits IP_DA, IP_SA, L4_DP, and L4_SP of each IP packet 402 constituting the mail stream BR to the GWI1, SWI, 2024, and 1000, respectively.

  Referring to FIG. 3 again, for example, when the WAN side packet receiving unit 26 in the packet transfer apparatus 101 receives the IP packet 402 constituting the mail stream BR from the server 151 via the WAN side port 28A, the WAN side packet receiving unit 26 sets the reception count value RCA. While incrementing, the following processing is performed while referring to the flow entry table FETbl held in the storage unit 27.

  That is, the WAN side packet receiving unit 26 acquires, for example, IP_DA, IP_SA and L4_DP, L4_SP from the received IP packet 402, and based on the acquired IP address and port number, the flow entry corresponding to the received IP packet 402 Is confirmed to be FE2.

  Then, the WAN side packet receiving unit 26 rewrites IP_DA and L4_DP of the received IP packet 402 to CLI2 and 2000, respectively, based on the items in the “downward” direction of the flow entry FE2, for example.

  For example, the WAN side packet receiving unit 26 outputs the IP packet 402 in which IP_DA and L4_DP are rewritten to the LAN side packet transmitting unit 23.

  For example, when receiving the IP packet 402 from the WAN side packet receiving unit 26, the LAN side packet transmitting unit 23 transmits the received IP packet 402 to the computer 121B indicated by the IP address CLI2 via the LAN side port 21.

  The packet transfer apparatus 101 performs the same processing every time it receives the IP packet 402 that constitutes the mail stream BR. In this way, the mail stream BR is transmitted from the server 151 to the computer 121B via the WAN side port 28A and the LAN side port 21 in the packet transfer apparatus 101 in the communication system 301.

[Transfer processing of mail stream C]
Hereinafter, the packet transfer apparatus 101 performs transmission / reception of the web information streams A and AR and the mail streams B and BR, and the flow entry table FETbl held in the storage unit 27 is different from the flow entry FE1, FE2 in FIG. Is registered, the packet transfer apparatus 101 newly receives a mail stream C from the computer 121A.

  Since the transfer process of the mail stream C is similar to the transfer process of the web information stream A described above, it will be briefly described below.

[Processing new packet of mail stream C]
Referring to FIGS. 3 and 5 again, the WAN-side packet transmission processing unit 25 can set the output destinations of a plurality of streams received in parallel from the same computer 121 to different physical ports, for example.

  Specifically, for example, the WAN side packet transmission processing unit 25 can set the output destinations of the web information stream A and the mail stream C received in parallel from the computer 121A to different physical ports.

  More specifically, for example, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 from the LAN side packet receiving unit 22, the received IP packet 402 receives IP_DA, IP_SA, L4_DP, and L4_SP. , SWI, CLI1, 1000, 2000, respectively.

  The used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27 and based on the acquired SWI, CLI1, 1000, and 2000, the IP received from the LAN side packet receiving unit 22 It is confirmed that the flow entry corresponding to the packet 402 is not registered. Then, the used port search unit 41 recognizes that the IP packet 402 is a new packet C, for example.

  For example, the used port search unit 41 outputs the new packet C to the routing table search unit 42. In addition, the used port search unit 41 outputs the new packet reception information to the used port determination unit 43 together with the new packet C, for example.

  For example, when the routing table search unit 42 receives a new packet C from the used port search unit 41, based on the content of the IP header of the received new packet C, the relationship between SWI, GWI1, and SWI, and SWI, GWI2, and SWI. Is acquired from the storage unit 27, and the acquired two relationships are output to the address conversion unit 45.

  For example, upon receiving new packet reception information and new packet C from the used port searching unit 41, the used port determining unit 43 confirms the latest packet flow rate A and packet flow rate B received from the flow rate monitoring unit 24.

  For example, the used port determining unit 43 confirms that the latest packet flow rate A is equal to or greater than the threshold Thp, and determines the WAN side port 28B as the used port. The used port determining unit 43 outputs, for example, “WAN2”, which is the logical port name of the determined WAN side port 28B, and the new packet C to the address converting unit 45.

  The address conversion unit 45 receives, for example, the relationship between SWI, GWI1, and SWI and the relationship between SWI, GWI2, and SWI from the routing table search unit 42, and receives “WAN2” and the new packet C from the used port determination unit 43. The following processing is performed.

  That is, the address conversion unit 45 creates, for example, original header information indicating the contents of the IP header and TCP header included in the new packet C, and outputs the created original header information to the stream information creation unit 29.

  For example, the address translation unit 45 recognizes that the relationship between SWI, GWI2, and SWI should be used based on “WAN2”, and changes the IP_SA included in the new packet C from CLI1 to GWI2 based on the relationship. rewrite.

  Further, the address conversion unit 45 rewrites L4_SP included in the new packet C to 2024th. Here, 2024 is the corresponding port number corresponding to CLI1 and 2000.

  For example, the address translation unit 45 creates and creates post-rewrite header information indicating the contents of the IP header and TCP header included in the new packet C (hereinafter also referred to as new packet C after rewriting) in which IP_SA and L4_SP are rewritten. The rewritten header information is output to the stream information creation unit 29 together with the logical port name “WAN2”.

  Further, the address conversion unit 45 outputs, for example, the logical port name “WAN2” and the rewritten new packet C to the transmission unit 44.

[Add Flow Entry]
The stream information creation unit 29 creates the flow entry FE3 shown in FIG. 4 by using the original header information, the header information after rewriting, and the logical port name “WAN2” received from the address translation unit 45, for example. It is additionally registered in the table FETbl.

  When the transmission unit 44 receives, for example, the logical port name “WAN2” and the rewritten new packet C from the address conversion unit 45, the transmission unit 44 receives the new logical port name “WAN2” that has been received. It is recognized that the packet C should be transmitted to the Internet 11 side via the WAN side port 28B.

  Then, for example, the transmitting unit 44 transmits the rewritten new packet C to the Internet 11 side via the WAN side port 28B, and increments the transmission count value TCB.

[Processing of subsequent packets of mail stream C]
Hereinafter, it is assumed that the packet transfer apparatus 101 newly receives an IP packet 402 subsequent to the new packet C.

  For example, when the used port search unit 41 in the WAN side packet transmission processing unit 25 receives the IP packet 402 following the new packet C from the LAN side packet reception unit 22, the IP_DA, IP_SA, L4_DP, L4_SP from the received IP packet 402. As SWI, CLI1, 1000 and 2000 respectively.

  The used port search unit 41 refers to, for example, the flow entry table FETbl held in the storage unit 27, and based on the acquired SWI, CLI2, 1000, 2000, and the flow entry FE3, the LAN side packet receiving unit The IP packet 402 received from the network 22 is recognized as the subsequent packet C.

  The used port search unit 41 outputs, for example, subsequent packet reception information indicating that the subsequent packet C has been received and that the flow entry FE3 should be referenced to the address conversion unit 45 together with the subsequent packet C.

  For example, when receiving the subsequent packet reception information and the subsequent packet C from the used port search unit 41, the address conversion unit 45 refers to the flow entry FE3 indicated by the received subsequent packet reception information, and includes the IP_SA and L4_SP is rewritten in the same manner as the new packet C.

  The address translation unit 45, for example, transmits a subsequent packet C in which IP_SA and L4_SP are rewritten (hereinafter also referred to as post-rewrite subsequent packet C) together with “WAN2” that is the “transmission logical port name” in the “upstream” direction. 44.

  For example, when receiving the logical port name “WAN2” and the rewritten subsequent packet C from the address converting unit 45, the transmitting unit 44 transmits the received rewritten subsequent packet C to the Internet 11 side via the WAN side port 28B. At the same time, the transmission count value TCB is incremented.

  The packet transfer apparatus 101 performs the same process every time it receives the IP packet 402 that constitutes the mail stream C. In this way, the mail stream C is transmitted from the computer 121A to the server 151 via the LAN side port 21 and the WAN side port 28B in the packet transfer apparatus 101 in the communication system 301.

[Mail stream BR]
Referring to FIG. 1 again, for example, when receiving the mail stream C from the packet transfer apparatus 101, the server 151 creates a mail stream CR that is a response stream of the received mail stream C, and creates the created mail stream CR. Transmit to the packet transfer apparatus 101.

  More specifically, for example, the server 151 sets and transmits IP_DA, IP_SA, L4_DP, and L4_SP of each IP packet 402 constituting the mail stream CR to the GWI2, SWI, 2024, and 1000, respectively.

  Referring to FIG. 3 again, for example, when the WAN side packet receiving unit 26 in the packet transfer apparatus 101 receives the IP packet 402 constituting the mail stream CR from the server 151 via the WAN side port 28B, the WAN side packet receiving unit 26 sets the reception count value RCB. While incrementing, the following processing is performed while referring to the flow entry table FETbl held in the storage unit 27.

  That is, the WAN side packet receiving unit 26 acquires, for example, IP_DA, IP_SA and L4_DP, L4_SP from the received IP packet 402, and based on the acquired IP address and port number, the flow entry corresponding to the received IP packet 402 Is FE3.

  Then, the WAN side packet receiving unit 26 rewrites IP_DA and L4_DP of the received IP packet 402 to CLI1 and 2000, respectively, based on each item in the “downward” direction of the flow entry FE3, for example.

  For example, the WAN side packet receiving unit 26 outputs the IP packet 402 in which IP_DA and L4_DP are rewritten to the LAN side packet transmitting unit 23.

  For example, when receiving the IP packet 402 from the WAN side packet receiving unit 26, the LAN side packet transmitting unit 23 transmits the received IP packet to the computer 121A indicated by the IP address CLI1 via the LAN side port 21.

  The packet transfer apparatus 101 performs the same process every time it receives the IP packet 402 that constitutes the mail stream CR. In this way, the mail stream CR is transmitted from the server 151 to the computer 121A via the WAN side port 28B and the LAN side port 21 in the packet transfer apparatus 101 in the communication system 301.

  Further, since the output destinations of the web information stream A and the mail stream C received in parallel from the computer 121A are the WAN ports 28A and 28B, respectively, the WAN side packet transmission processing unit 25 receives from the same computer 121 in parallel. The output destinations of multiple streams are set to different physical ports.

  As described above, when the number of packets transmitted / received in the WAN side port 28A per unit time is equal to or greater than the threshold Thp, the communication load of the optical line is configured by transmitting / receiving the stream using the WAN side port 28B. Can be offloaded to communication media conforming to the LTE standard, and communication load can be distributed while improving the communication speed between the packet transfer apparatus 101 and the server 151.

  In addition, with the configuration in which the output destination of the stream is fixed to either the WAN side port 28A or 28B, the IP address of each IP packet in the stream received by the server 151 can be unified for each stream. The stream transmission between 151 can be performed satisfactorily.

[Operation]
The packet transfer apparatus 101 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads and executes a program including a part or all of each step of the following flowchart from a memory (not shown). The program of this apparatus can be installed from the outside. The program of this device is distributed in a state stored in a recording medium.

  FIG. 6 is a flowchart defining an operation procedure when the packet transfer apparatus according to the embodiment of the present invention performs a packet transfer process.

  Referring to FIG. 6, first, packet transfer apparatus 101 waits until predetermined time Tf elapses or until IP packet 402 is received from computer 121 (NO in step S102 and NO in step S106).

  Next, when the predetermined time Tf has elapsed (YES in step S102), the packet transfer apparatus 101 calculates the packet flow rates A and B based on the transmission count values TCA and TCB and the reception count values RCA and RCB (step S104). ).

  Next, the packet transfer apparatus 101 waits until the predetermined time Tf elapses or until the IP packet 402 is received from the computer 121 (NO in step S102 and NO in step S106).

  When the packet transfer apparatus 101 receives the IP packet 402 from the computer 121 (YES in step S106), the packet transfer apparatus 101 performs the following processing.

  That is, the packet transfer apparatus 101 acquires IP_DA, IP_SA, L4_DP, and L4_SP as header information from the received IP packet 402, and determines whether or not a flow entry corresponding to the acquired header information is registered in the flow entry table FETbl. Confirm (step S108).

  Next, the packet transfer apparatus 101 determines that the flow entry corresponding to the header information is not registered in the flow entry table FETbl and the packet flow rate A is greater than or equal to the threshold Thp (NO in step S108 and in step S112). YES), the used port is determined to be the WAN side port 28B (step S116).

  Next, the packet transfer apparatus 101 creates a flow entry including “WAN2” which is the logical name of the determined used port, and registers the created flow entry in the flow entry table FETbl (step S118).

  On the other hand, when the flow entry corresponding to the header information is not registered in the flow entry table FETbl and the packet flow rate A is smaller than the threshold Thp, the packet transfer apparatus 101 (NO in step S108 and NO in step S112). The used port is determined to be the WAN side port 28A (step S114).

  Next, the packet transfer apparatus 101 creates a flow entry including “WAN1”, which is the logical name of the determined used port, and registers the created flow entry in the flow entry table FETbl (step S118).

  Next, the packet transfer apparatus 101 transmits the IP packet 402 from the determined WAN side port 28A or 28B (step S120).

  Next, the packet transfer apparatus 101 waits until the predetermined time Tf elapses or until a new IP packet 402 is received from the computer 121 (NO in step S102 and NO in step S106).

  Further, when the flow entry corresponding to the header information is registered in the flow entry table FETbl (YES in step S108), the packet transfer apparatus 101 sets the use port to the WAN side port 28A or 28B according to the registered flow entry. (Step S110).

  Next, the packet transfer apparatus 101 transmits the IP packet 402 from the determined WAN side port 28A or 28B (step S120).

  In the packet transfer apparatus according to the embodiment of the present invention, the packet is selectively output to a plurality of physical ports on the Internet 11 side, but the present invention is not limited to this. The packet transfer apparatus is not limited to the Internet 11 side, and may be configured to selectively output packets to a plurality of physical ports on the LAN 10 side, as in the Internet 11 side, or a combination of these two types of configurations. Also good.

  By the way, for example, in a packet transfer apparatus having a plurality of physical ports, there is a case where it is desired to distribute the communication load when the communication load is concentrated on one physical port.

  For example, in the packet transfer apparatus described in Patent Literature 1, when the traffic volume of the traffic to be monitored exceeds a predetermined threshold for the bandwidth of the physical port, the traffic of the physical port in the logical port is redistributed. .

  For example, when traffic is redistributed while a stream composed of a plurality of packets is being transmitted, the physical port through which the stream passes may be different before and after the traffic redistribution.

  For example, if traffic redistribution occurs when a different IP address is assigned to each physical port, the identity of the IP address of the stream transmission source cannot be ensured, and the stream transmission may not be performed well. is there.

  On the other hand, in the packet transfer apparatus according to the embodiment of the present invention, the WAN side packet transmission processing unit 25 selectively outputs a packet to a plurality of physical ports of the packet transfer apparatus 101. The flow rate monitoring unit 24 monitors the packet flow rate at each physical port. The WAN-side packet transmission processing unit 25 determines a use port that is a physical port to be a packet output destination based on the packet flow rate monitored by the flow rate monitoring unit 24. Then, the WAN-side packet transmission processing unit 25 fixes the output destination of other packets in the stream to which the packet whose output destination is determined belongs to the port used.

  In this way, by fixing the output destination of each packet belonging to the stream to the use port determined based on the packet flow rate, the output destination of the stream is fixed to, for example, a physical port where the communication load is not concentrated. Can do. Thereby, for example, even when different IP addresses are assigned to each physical port, it is possible to ensure the identity of the IP address of the stream transmission source while distributing the communication load. Therefore, in a configuration in which packets are selectively output to a plurality of physical ports, stream transmission can be performed satisfactorily while the communication load is distributed.

  Further, in the packet transfer apparatus according to the embodiment of the present invention, the WAN-side packet transmission processing unit 25 performs a new process based on the packet flow rate when the packet transfer apparatus 101 receives a new packet that is a packet of a new stream. Determine the port of use for the packet.

  With such a configuration, the output destination of all the packets belonging to the stream can be fixed to the determined used port.

  In the packet transfer apparatus according to the embodiment of the present invention, the stream information creation unit 29 creates stream information indicating the correspondence between the stream and the used port, specifically, a flow entry and saves it in the storage unit 27. To do. When the packet transfer apparatus 101 receives a packet, the WAN-side packet transmission processing unit 25 refers to the flow entry. If the stream to which the received packet belongs is included in the flow entry, the WAN-side packet transmission processing unit 25 sends the packet to the use port corresponding to the stream. Output.

  With such a configuration, other packets in the stream received after determining the use port of a certain stream can be output to the use port by simple processing.

  In the packet transfer apparatus according to the embodiment of the present invention, the WAN-side packet transmission processing unit 25 preferentially uses a predetermined physical port as a use port, and determines that the packet flow rate at the predetermined physical port is large. Then, change the used port to another physical port.

  With such a configuration, a specific physical port can be preferentially used, and communication of the physical port can be offloaded to another physical port when the packet flow rate is large.

  In the packet transfer apparatus according to the embodiment of the present invention, the WAN-side packet transmission processing unit 25 can set output destinations of a plurality of streams received in parallel from the same computer 121 to different physical ports. .

  With such a configuration, in the packet transfer apparatus 101, output destinations of a plurality of streams received in parallel from the same computer 121 can be fixed to different physical ports, for example, depending on the stream type. Different communication paths can be established.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The above description includes the following features.

[Appendix 1]
A packet transfer apparatus in a communication system for transmitting a stream composed of a plurality of packets,
A transmission processing unit that selectively outputs the packet to a plurality of physical ports of the packet transfer device;
A monitoring unit that monitors the flow rate of the packet in each physical port;
The transmission processing unit determines a use port which is the physical port to be an output destination of the packet based on the flow rate monitored by the monitoring unit,
The transmission processing unit fixes the output destination of another packet in the stream to which the packet to which the output destination is determined belongs to the use port regardless of the flow rate after the use port is determined,
The packet comprises an IP packet;
The physical port is a physical port for connecting to the Internet,
Different IP addresses are assigned to the plurality of physical ports,
The transmission processing unit selectively outputs the packet to the physical port connected to an optical line and the physical port connected to a communication medium in accordance with the LTE standard,
The packet transfer apparatus, wherein the flow rate of the packet is a quantity of the packet or a data amount of the packet.

21 LAN side port 22 LAN side packet receiving unit 23 LAN side packet transmitting unit 24 Flow rate monitoring unit 25 WAN side packet transmission processing unit 26 WAN side packet receiving unit 27 Storage unit 28A, 28B WAN side port 29 Stream information creating unit 30 Counter 31 Routing table creation unit 41 Used port search unit 42 Routing table search unit 43 Used port determination unit 44 Transmission unit 45 Address conversion unit 101 Packet transfer device 121A, 121B Computer 151 Server 301 Communication system

Claims (7)

A packet transfer apparatus in a communication system for transmitting a stream composed of a plurality of packets,
A transmission processing unit that selectively outputs the packet to a plurality of physical ports of the packet transfer device;
A monitoring unit that monitors the flow rate of the packet in each physical port;
The transmission processing unit determines a use port which is the physical port to be an output destination of the packet based on the flow rate monitored by the monitoring unit,
The packet transmission apparatus, wherein the transmission processing unit fixes an output destination of another packet in the stream to which the packet for which the output destination is determined belongs to the used port.   2. The packet according to claim 1, wherein the transmission processing unit determines the use port of the new packet based on the flow rate when the packet transfer apparatus receives a new packet that is a packet of the new stream. Transfer device. The packet transfer device further includes:
An information creation unit that creates and holds stream information indicating a correspondence relationship between the stream and the used port;
The transmission processing unit refers to the stream information when the packet transfer apparatus receives the packet, and corresponds to the stream when the stream to which the received packet belongs is included in the stream information. The packet transfer apparatus according to claim 2, wherein the packet transfer apparatus outputs to the used port.   The transmission processing unit preferentially designates a predetermined physical port as the used port, and changes the used port to another physical port when it is determined that the flow rate in the predetermined physical port is large. The packet transfer apparatus according to any one of claims 1 to 3.   The packet according to any one of claims 1 to 4, wherein the transmission processing unit can set different physical ports as output destinations of the plurality of streams received in parallel from the same device. Transfer device. A packet transfer method in a packet transfer apparatus in a communication system for transmitting a stream composed of a plurality of packets,
The packet transfer device selectively outputs the packet to a plurality of own physical ports,
Monitoring the packet flow rate at each of the physical ports;
Determining a used port which is the physical port to be the output destination of the packet based on the flow rate;
Fixing the output destination of another packet in the stream to which the packet to which the output destination has been determined belong to the port to be used. A packet transfer program used in a packet transfer apparatus in a communication system for transmitting a stream composed of a plurality of packets,
The packet transfer device selectively outputs the packet to a plurality of own physical ports,
On the computer,
Monitoring the packet flow rate at each of the physical ports;
Determining a used port which is the physical port to be the output destination of the packet based on the flow rate;
And a step of fixing an output destination of another packet in the stream to which the packet to which the output destination is determined belong to the use port.

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