JP2009147795A - Virtual private line apparatus, connection method thereof and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve communication quality in a virtual private line apparatus connected by a plurality of lines. <P>SOLUTION: The virtual private line apparatus 601 is provided with: a control part 615 for determining a combination of connections based on a measurement result obtained by measuring communication quality about combinations of a plurality of WAN-side packet output parts 616 to 618 and a plurality of WAN-side packet input parts of an opposite virtual private line apparatus and determining a rate of packets to be transmitted to respective WAN-side packet output parts, and the WAN-side packet input part of the opposite virtual private line apparatus to which packets are transmitted from respective WAN-side packet output parts; a selector 614 for distributively transmitting capsulated packets capsulated by the capsulation apparatus 613 to the plurality of WAN-side packet output parts 616 to 618 at the rate determined by the control part 615; and the plurality of WAN-side packet output parts 616 to 618 for transmitting the capsulated packets to the WAN-side packet input part of the opposite virtual private line apparatus 602 which is determined by the control part 615. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a virtual leased line device using a packet switching network, a connection method thereof, and a program.

Between virtual leased line devices connected by a plurality of lines, packets input to the transmission source device are distributed and sent to the partner device. FIG. 1 shows an example in which apparatus A and apparatus B are connected by three WAN lines (IP network). Here, when packet data is transferred from apparatus A to apparatus B, the following processing is performed.
(1) A plurality of lines are selected in round robin, and packet data input from the LAN side of apparatus A is transferred using the selected lines.
(2) In the device B, packet data transferred from a plurality of WAN lines are collected and sent to the LAN side.

The above processing may be performed while considering the bandwidth of the line. Processing in this case is performed as follows.
(1) The ratio of the line bandwidth is calculated, and the ratio of the number of transfers for each line is determined.
(2) When a packet is input from the LAN side of the device A, a line is selected according to the ratio of the number of transfers, and the packet data is transferred to the device B.
(3) In the device B, the packets sent separately from the plurality of WAN lines are combined and sent to the LAN side.

Conventionally, such a device is
(1) Improvement of robustness and reliability by redundancy using multiple lines,
(2) High speed using multiple lines,
(3) Security improvement by packet distribution,
Has been used for the purpose.

  The prior art documents using a plurality of lines are shown below.

Yasue Watanabe, Toshio Okabe, Motonori Nakamura, “Design and Implementation of TCP-Friendly Streaming System Utilizing Multiple Paths”, IEICE Tech. IA-2006-37, IEICE, January 2007, p. 37-42 Marubeni Solution Co., Ltd., “Dedicated machine for simultaneous connection to multiple access lines” [online], February 21, 2002, [November 12, 2007 search], Internet <URL: http: // www. marubeni-sys.com/news/msol/2002/0409.html> FatPipe Networks Inc, “FatPipe MPVPN provides the highest level of VPN security”, [online], [searched November 12, 2007], Internet <URL: http://www.fatpipeinc.com/mpvpn/index.html >

  The Internet is designed as a network for data communication, and until now, much attention has not been given to line quality such as delay and bandwidth, but in recent years, streaming and the like have been performed on the Internet. Further improvement in communication quality, such as speeding up and guarantee of delay time, has become an issue.

  In the conventional virtual leased line apparatus, when a plurality of lines are used, an administrator empirically determines a combination of line connections between apparatuses. However, in order to improve communication quality such as bandwidth, delay, packet loss rate, etc., it is important to appropriately set the combination of line connections between devices while measuring the communication quality of the line. This is described below.

  Due to ISP management policies, the communication quality between ISPs is not uniform, and when measured, the communication quality between ISPs often varies considerably. As an index of communication quality, usable actual bandwidth, delay and jitter, packet loss rate, and the like can be considered. However, only the actual bandwidth is considered for the explanation below.

  When a plurality of connections are made via IP networks using different ISPs, some combinations are conceivable as connection forms as shown in FIG. In FIG. 2, two examples of connection between devices are shown as solid and broken arrows, but there are actually six combinations of connections. If the number of WAN-side ports of the opposing devices is n, the number of combinations is the factorial of n. The bandwidth that can be used on the virtual leased line constructed using this device is the sum of the actual bandwidth of each line.

  Now, it is assumed that usable real bandwidths between ISPs connected to the WAN side ports of the devices A and B of FIG. 2 are obtained as shown in FIG. The combination of these WAN side ports is as shown in FIG. The combination of the real bands is maximized in the combination 4 and a speed of 11 Mbps is obtained. Further, the total sum of the actual bands is the minimum of the combination 1 of 3 Mbps, and the difference from the maximum value is 8 Mbps.

  In the above, it has been explained that the usable bandwidth can be improved by appropriately selecting the combination of connections. Similarly, the combination of connections is also important for the delay. That is, as with the bandwidth, communication quality can be improved by selecting a combination that minimizes the maximum delay between ISPs. The same is true for jitter.

  Thus, it is important for improving the quality of the virtual circuit to actually measure the communication quality of the line and appropriately set the combination of line connections between the apparatuses based on the actual measurement.

However, until now, when setting the line connection combination,
(1) Without measuring communication quality
(2) The manager of the apparatus often decides arbitrarily based on experience, and it cannot always be said that an appropriate setting has been made. Also,
(3) Since the setting is performed manually, there is a problem that the human cost increases.

  An object of the present invention is to improve communication quality in a virtual leased line device connected by a plurality of lines.

  Of the inventions disclosed in this specification, the outline of typical ones will be briefly described as follows.

  A first invention is a virtual leased line device for connecting a plurality of WAN side packet output units to a plurality of WAN side packet input units of a counterpart virtual leased line device, wherein the plurality of WAN side packet output units and a counterpart virtual Proportion of packets to be determined based on measurement results obtained by measuring communication quality for a combination of a plurality of WAN side packet input units of a leased line device, and to be transmitted to each WAN side packet output unit based on the determined combination A control unit that determines a WAN side packet input unit of a destination virtual private line device to be transmitted from each WAN side packet output unit, and a flow identifier grant packet assigned a flow identifier by the flow identifier grant unit, A selector for distributing and transmitting to a plurality of WAN side packet output units at a determined ratio, and a flow identifier giving packet received from the selector Characterized in that it comprises a plurality of WAN side packet output unit to be transmitted to the WAN side packet input unit destined partner virtual private device the control unit has determined.

  A second invention includes a plurality of WAN side packet input units that transmit flow identifier assignment packets received from a plurality of WAN side packet output units of the counterpart virtual dedicated line device to the flow identifier removal unit in the first invention. It is characterized by that.

  According to a third aspect, in the second aspect, after the packet sent from the LAN side packet input unit is temporarily stored in the packet memory, the packet is transmitted to the flow identifier adding unit, and from the flow identifier removing unit The packet sent is temporarily stored in the packet memory and then transmitted to the LAN side packet output unit.

  According to a fourth invention, in the second or third invention, all the addresses of the plurality of WAN side packet input units and output units are set, and one of the plurality of WAN side packet input units and output units is set. One of the destination addresses is set in the destination address, a probe packet is sent to the destination address, and each WAN line is connected based on the address information sent from the destination dedicated line device to establish a virtual dedicated line connection. It is characterized by doing.

  The fifth invention is the first to fourth inventions, in which the measurement of the communication quality is continued even after the connection with the counterpart virtual leased line device is set based on the combination determined by the control unit, and the measurement result Based on the above, the combination to be connected is updated.

  According to a sixth invention, in the first to fifth inventions, the measurement result of communication quality and / or the determined combination is stored in the storage device as a history, and is stored in the storage device at the time of subsequent activation. It is characterized in that it can be used immediately after activation based on the measurement result of communication quality and / or the determined combination.

  According to a seventh invention, in the first to sixth inventions, when the required communication quality is the size of a band, a combination that maximizes the total bandwidth is adopted, and each WAN for the total bandwidth is used. The ratio of packets to be transmitted to each WAN side packet output unit is determined by the ratio of the bandwidth of the line.

  An eighth invention is characterized in that, in the first to sixth inventions, when the required communication quality is real-time, a combination is adopted such that the maximum delay value of each WAN line is minimized. To do.

  According to the present invention, since the communication quality of each line is measured and a combination of line connections corresponding to the quality required for the virtual private line can be selected, the communication quality can be improved.

  The best embodiment of the present invention will be described below with reference to the drawings.

  FIG. 5 shows the flow of packet data in the embodiment of the present invention. In this embodiment, the flow identifier is assigned along with the encapsulation. In FIG. 5, 501 is a VPN apparatus A, 502 is a VPN apparatus B, and 503 is an IP network (WAN). Awan1, Awan2, and Awan3 are ports connected to the IP network (WAN) of the VPN apparatus A501. ALan1 is a port connected to the LAN of the VPN apparatus A501. Bwan1, Bwan2, and Bwan3 are ports connected to the IP network (WAN) of the VPN apparatus B502. BLan1 is a port connected to the LAN of the VPN apparatus A501.

  Packets 1, 2, and 3 are input to the port Alan1 of the VPN apparatus A501 from the LAN side. From the VPN apparatus A501, the encapsulated packet 1 ′ is transferred from the port Awan1 to the port Bwan1 of the VPN apparatus B502, the encapsulated packet 2 ′ is transferred from the port Awan2 to the port Bwan2 of the VPN apparatus B502, and the encapsulated packet 3 ′ is transferred from the port Awan3 to the VPN. The data is transmitted to the port Bwan3 of the device B502. The VPN apparatus B502 decapsulates the encapsulated packets 1 ', 2', and 3 ', and outputs packets 1, 2, and 3 reconfigured (reverted) from BLan1 to the LAN side.

  540 is a diagram showing details of an IP packet input from the LAN side to the port Alan1 of the VPN apparatus A501, 541 is an IP header, and 542 is a payload.

  550 is a diagram showing details of the encapsulated packet transmitted from the port Awan1 of the VPN apparatus A501, 551 is an encapsulated header, and 552 is a normal IP packet.

  553 is a diagram showing details of the encapsulation header 551. 554 is a diagram showing the encapsulation header 553 in more detail, 555 is an IP header, 556 is a sequence number, and 557 is a label. The IP header 555 is a header added for WAN line transmission. The sequence number 556 is a number indicating the order of encapsulated packets added to prevent reversal of the packet order. Label 557 is a label added for flow identification.

  560 is a diagram showing details of the reconstructed packet output from the port BLan1 of the VPN apparatus B502 to the LAN side, 561 is an IP header, and 562 is a payload.

The outline of the operation of the apparatus will be described below with reference to FIG.
(1) A packet input to the VPN apparatus A501 from the LAN side includes (a) a label 557 for identifying a flow, (b) a sequence number 556 for preventing reversal of the packet order, (C) An “encapsulation header” 554 composed of an IP header 555 for WAN transfer is added and encapsulated.
(2) The encapsulated packet is sent to the VPN apparatus B502 via a plurality of lines.
(3) The capsule device is decapsulated in the VPN apparatus B502 (decapsulation) and sent to the LAN side so that the packet order does not change for each flow.

  Note that a label 557 used for flow identification in the encapsulation header is uniquely determined by four of Source IP address, Destination IP address, Source port, and Destination port.

  An internal schematic diagram of the virtual leased line apparatus according to the embodiment of the present invention is shown in FIG.

  Reference numeral 601 denotes a virtual leased line device (multi-path VPN device) according to an embodiment of the present invention. 611 is a LAN side packet input unit, 612 is a packet memory, 613 is an encapsulation device, 614 is a selector, 615 is a control unit, 616 is a WAN side packet output unit (G1out), 617 is a WAN side packet output unit (G2out) , 618 is a WAN side packet output unit (G3out), 619 is a WAN side packet input unit (G1in), 620 is a WAN side packet input unit (G2in), 621 is a WAN side packet input unit (G3in), and 622 is a communication quality measurement. 623 is a decapsulation device, 624 is a packet memory, 625 is a LAN side packet output unit, and 626 is a storage device used for storing history data and the like.

  Reference numeral 602 denotes a counterpart virtual leased line device connected to the virtual leased line device 601 via the WAN 603. 631 is a WAN side packet input unit (B1in), 632 is a WAN side packet input unit (B2in), 633 is a WAN side packet input unit (B3in), 634 is a WAN side packet output unit (B1out), and 635 is a WAN side packet output. Sections (B2out) and 636 are WAN side packet output sections (B3out). The other configurations are the same as those of the virtual leased line device 601 and are therefore omitted.

  The virtual leased line device 601 has a plurality of WAN (Wide Area Network) ports for connection to a packet switching network and a LAN (Local Area Network) port for connection to a local network of a base. The inside of the virtual leased line device 601 includes LAN side packet input / output units 611 and 625, packet memories 612 and 624, a selector 614, a control unit 615, and WAN side packet input / output units 616 to 621. The outline of the function of each part is as follows.

(A) LAN side packet input unit 611 and output unit 625
The packet sent from the LAN line is stored in the packet memory 612, and the packet data collected from the WAN line and reconstructed is sent to the LAN side.

(B) Packet memories 612 and 624
A memory for storing packet data. The packet transmitted from the LAN side packet input unit 611 is temporarily stored in the packet memory 612 and then transmitted to the encapsulation device 613. Further, the packet sent from the decapsulation device 623 is temporarily stored in the packet memory 624 and then transmitted to the LAN side packet output unit 625. The packet memories 612 and 624 are used to absorb jitter and avoid communication interruption due to combination switching. It is also used to prevent packet order reversal.

(C) Encapsulation device 613
An “encapsulation header” (see 554 in FIG. 5) is added to the packet from the LAN side. The encapsulation header includes a flow identifier (a label and a sequence number for identifying a flow) and a transfer IP header. Note that the destination address is still blank here.

(D) Decapsulation device 623
While looking at the sequence number of the encapsulation header, the encapsulation header is removed so that the packet order is not reversed in the flow while the packet entered from the WAN side is transmitted to the LAN side.

(E) Selector unit 614
The packets encapsulated by the encapsulating device 613 are distributed and transmitted to the plurality of WAN side packet output units 616, 617, and 618 at a rate specified by the control unit 615. Here, the destination IP address of the encapsulation header is set.

  As a packet distribution method, the simplest one is a “round robin method” in which divided data is sequentially assigned to a WAN port and sent. Although this method has the advantage of simple implementation, it assumes that the bandwidth of the line is uniform, so it is not suitable for use in a heterogeneous network environment. In this embodiment, the method of determining the packet data division ratio according to the bandwidth of each WAN line is the first selection.

(F) Control unit 615
The control unit 615 includes the following elements.
-Destination calculation means A combination table is created based on the measurement data from the communication quality measurement unit 622, and an optimum combination of routes is determined so as to satisfy the quality required for the flow.
Dispersion ratio determining means The division ratio of packet data to be sent to the WAN side port is instructed based on the packet distribution ratio table.
Destination address setting means A destination selection table is created by the best combination in the combination table, and a destination selector for each WAN side port is set based on the destination selection table.

(G) WAN side packet input units 619 to 621 and output units 616 to 618
The encapsulated packet transmitted from the WAN 603 is received and forwarded to the decapsulator 623. In addition, the encapsulated packet sent from the selector 614 is transmitted to the WAN 603. Also, counters related to communication quality are provided, and counters for observing communication quality such as usable bandwidth, delay, jitter, packet loss rate, etc. are mounted for each path.

(H) Communication quality measurement unit 622
In the initial stage before establishing the VPN connection, a dummy packet is sent to the counterpart device (virtual leased line device 602), and the initial communication quality is measured. Even after the VPN connection is established, the traffic between both devices is continuously monitored and the communication quality is measured. In addition, when there is no traffic or when there is little traffic, dummy packets are periodically sent to the partner device to generate pseudo traffic to monitor whether there is a change in communication quality.

  Next, the operation of the virtual leased line apparatus handled in the embodiment of the present invention will be described with reference to FIG. The operation of the virtual leased line device 601 in the embodiment of the present invention consists of three phases.

  The operation for each phase of the apparatus will be described below.

[Communication quality measurement phase]
(0) Establish an initial ground connection (connection with a destination point). At this time, Path MTU Discovery (IETF RFC 1191) is used so as not to cause packet fragmentation that causes transfer performance degradation. These input / output units are given unique addresses belonging to different networks for each port. These addresses have a 32-bit address system compliant with IP (Internet Protocol). Then, a connection is established between the own address and the destination address, and these are bundled to form one virtual dedicated line.
(1) Transmit a dummy packet for measurement for a certain period of time.
(2) The communication quality measuring unit 622 observes communication quality such as a used band, a usable actual band, delay, jitter, packet loss rate, and notifies the control unit 615 of the result.
(3) When the quality measurement ends with one combination, the control unit 615 controls the WAN interface, establishes a virtual private line connection with another path combination, and returns to (1). This is repeated for the number of combinations. When all combinations have been measured, a table as shown in FIG. 7 is obtained for each communication quality.

  FIG. 7 is a table showing the actual bandwidth between the ports measured in this example. FIG. 7 shows that the actual bandwidth from the output port G1out616 of the virtual leased line device 601 to the input port B1in631 of the counterpart virtual leased line device 602 is 1 Mbps, the actual bandwidth from G1out616 to B2in632 is 5 Mbps, and from G1out616 to B3in633. , The actual bandwidth from the output port G2out617 of the virtual leased line device 601 to the input port B1in631 of the counterpart virtual leased line device 602 is 2 Mbps, and so on.

  Depending on the usage scene of the apparatus, it is required that the apparatus can be used immediately after the apparatus is activated. The communication quality measurement phase requires a certain amount of measurement time, and it is necessary to omit this communication quality measurement so that it can be used immediately after startup. However, if measurement of communication quality is omitted, an appropriate combination cannot be obtained. Therefore, the communication quality measurement result and the optimum combination when the device was previously operated are stored in the storage device 626 as a history so that the time until connection establishment can be shortened.

[Combination determination phase]
(1) Based on the communication quality data (FIG. 7) obtained by the measurement, the optimum combination for the quality required for the flow is determined as shown in the combination table 801 in FIG. For example, when the required communication quality is the size of the bandwidth, a combination that maximizes the total bandwidth among the combinations of the transmission source and the destination is adopted. Similarly, when real-time performance is most required, a combination that minimizes the maximum delay value of each WAN line may be employed.

  FIG. 8 is a diagram showing a table created by the control unit 615. 801 is a combination table created by the destination calculation means of the control unit 615, 802 is a packet distribution ratio table created by the distribution ratio determining means of the control unit 615, and 803 is a destination selection table created by the destination address setting means of the control unit 615. is there.

  In the combination table 801, combination 1 is a case where the output port G1out616 of the virtual dedicated line device 601 is connected to the input port B1in631 of the counterpart virtual dedicated line device 602, G2out617 to B2in632, and G3out618 to B3in633. “/ 1” indicates that the actual bandwidth of the connection is 1 Mbps. This actual band is based on FIG. 7 obtained by measurement. In the case of the combination 1, the total bandwidth is 1 Mbps + 1 Mbps + 1 Mbps = 3 Mbps. The case of connection by this combination 1 is shown in FIG.

  In the combination table 801, the combination 4 is a case where the output port G1out616 of the virtual leased line device 601 is connected to the input port B2in632 of the counterpart virtual leased line device 602, G2out617 to B3in632, and G3out618 to B1in631. The actual bandwidth from G1out616 to B2in632 is 5 Mbps, the actual bandwidth from G2out617 to B3in632 is 5 Mbps, and the actual bandwidth from G3out618 to B1in631 is 1 Mbps. Therefore, the total bandwidth of the combination 4 is 11 Mbps, and the highest total bandwidth is obtained by this combination. Therefore, the virtual leased line device 601 of this embodiment determines the combination 4 as a combination to be connected.

  (2) Based on the combination table 801 in (1), a packet distribution ratio table 802 is created as shown in FIG. 8 and set in the selector 614. Further, a destination selection table 803 for each WAN side port is created based on the combination table 801, and the destination selectors of the WAN side packet output units 616 to 618 are set based on this.

  That is, based on the packet distribution ratio table 802, the distribution ratio determination means of the control unit 615 sets the packet distribution ratio in the selector 614. As a result, the selector 614 distributes packets at a rate of 45% for G1out 616, 45% for G2out 617, and 9% for G3out 618. The distribution ratio in the packet distribution ratio table 802 is the ratio of the actual bandwidth of each WAN line to the total bandwidth. The total of the distribution ratios in the packet distribution ratio table 802 is not 100% because it is described with the decimal part omitted, and the total is actually 100%.

  Based on the destination selection table 803, the destination address setting means of the control unit 615 uses the destination selector of G1out616 as B2in632 as the destination, the destination selector of G2out617 as the destination of B3in633, and the destination selector of G3out618 as the destination. B1in631 is set as the transmission destination.

(3) Connect each line and establish a virtual private line connection.
(4) The combination history is stored in the storage device 626.
FIG. 9 shows a state of connection with the counterpart virtual leased line device in the case of combination 4 in the combination table 801 in FIG.

[Data transfer phase]
In the virtual leased line device (multi-path VPN device) of FIG. 6, the following operations are performed during data transfer.

In the transmission side apparatus, the following processing is performed.
(1) A packet input from the LAN side packet input unit is first transferred to the packet memory 612.
(2) The packet data stored in the packet memory 612 is sent to the encapsulating device 613 and encapsulated.
(3) The encapsulated packet data is sent to each WAN side packet output unit 616 to 618 by the selector as shown in FIG. 9, and is distributed to a plurality of WAN lines and sent out.

On the other hand, the following processing is performed in the receiving side device.
(1) The encapsulated packet sent from the counterpart device is decapsulated in the order of the sequence number of the encapsulation header.
(2) Send to the LAN side packet input / output unit.

The initial connection can be automated as follows.
(1) All self addresses of a plurality of WAN side input / output units of two opposing virtual leased line devices are set. One of the destination addresses is set in one of the WAN side input / output units of the virtual dedicated line device on one side.
(2) The virtual leased line device on one side becomes the master and skips the probe packet to the destination address. The partner device that becomes the slave side returns a packet including its own address information.
(3) Based on the address information sent from the slave side device, the WAN side is connected from the master side to establish a virtual private line connection.

In the end, the present embodiment performs processing related to destination selection so as to satisfy the communication quality required by the flow as follows.
(1) A destination IP address is set to the interfaces of the WAN side packet output units 616 to 618 and a connection with the counterpart virtual private line device 602 is established. The initial destination is determined appropriately.
(2) The dummy packet is transferred to the destination virtual private line device 602 for a certain time required for quality measurement. A communication quality measuring unit 622 that monitors the WAN side packet measures the available bandwidth, delay, and packet loss rate at that time, and their maximum value, minimum value, average, variance, and so on.
(3) The destination determined in (1) is changed to another destination to establish a connection, and the measurement of (2) is performed again. This is repeated to measure all combinations of the source and destination.
(4) Based on the measurement result, processing is performed by a program so that the flow to be transferred matches the required communication quality as much as possible, and an optimum combination of WAN ports is determined to establish a connection. The required quality of a flow is basically determined by the type of the flow (whether streaming or data), but the user can change the required quality in advance.
(5) Even after the optimal combination is set in (4), the communication quality is continuously observed, and the optimal combination is recalculated based on preset conditions such as elapsed time and change in communication quality. The connection with the destination device is updated. At this time, the packet memory is used to avoid communication interruption.
As described above, the quality of the virtual dedicated communication line is improved.

  As described above, the virtual leased line device 601 has been described in detail based on the embodiment. However, the virtual leased line device 601 basically includes a plurality of WAN side packet output units 616 to 618 and the counterpart virtual leased line device 602. Based on the measurement result of measuring the communication quality for the combination of the plurality of WAN side packet input units 631 to 633, the combination to be connected is determined, and the ratio of the packets to be transmitted to each WAN side packet output unit based on the determined combination; A flow identifier is assigned by a control unit 615 that determines a WAN side packet input unit of a destination virtual private line device to be transmitted from each WAN side packet output unit and a flow identifier assigning unit (corresponding to the encapsulation device 613 in the embodiment). The flow identifier giving packets (corresponding to the encapsulated packets in the embodiment) are sent to a plurality of WAN side packets at the rate determined by the control unit 615. A selector 614 that distributes and transmits to the packet output units 616 to 618, and a flow identifier assignment packet received from the selector 614 is transmitted to the WAN side packet input unit of the destination virtual dedicated line device 602 determined by the control unit 615. And a plurality of WAN side packet output units 616 to 618.

  Also, flow identifier assignment packets received from the plurality of WAN side packet output units 634 to 636 of the counterpart virtual private line device 602 are transmitted to a flow identifier removal unit (corresponding to the decapsulation device 623 in the embodiment) that removes the flow identifier. A plurality of WAN side packet input units 619 to 621 may be provided.

  The packet sent from the LAN side packet input unit 611 is temporarily stored in the packet memory 612 and then transmitted to the flow identifier adding unit (corresponding to the encapsulation device 613 in the embodiment), and the flow identifier removing unit The packet sent from (corresponding to the decapsulation device 623 of the embodiment) may be temporarily stored in the packet memory 624 and then transmitted to the LAN side packet output unit 625.

  FIG. 10 shows a basic flowchart of the connection method of the virtual leased line device 601. In step 1001, the control unit 615 determines the communication quality of the combination of the plurality of WAN side packet output units 616 to 618 and the plurality of WAN side packet input units 631 to 633 of the counterpart virtual dedicated line device 602 based on the measurement result. The combination to be connected is determined, the ratio of packets to be transmitted to each WAN side packet output unit based on the determined combination, and the WAN side packet input unit of the destination virtual dedicated line device 602 to be transmitted from each WAN side packet output unit To decide. In step 1002, the selector 614 selects the flow identifier grant packet (corresponding to the encapsulated packet in the embodiment) to which the flow identifier is assigned by the flow identifier assigning unit (corresponding to the encapsulation device 613 in the embodiment), and the controller 615 The data is distributed and transmitted to the plurality of WAN side packet output units 616 to 618 at the determined ratio. In step 1003, the plurality of WAN side packet output units 616 to 618 send the flow identifier assignment packets received from the selector 614 to the WAN side packet input unit 631 to 633 of the counterpart virtual private line device 602 determined by the control unit 615. Send to.

  In the embodiment shown in FIG. 6, the virtual leased line device 601 includes three WAN side packet output units, but any number of WAN side packet output units may be used. Further, in the embodiment shown in FIG. 6, the virtual leased line apparatus 601 has three WAN side packet input units, but any number of WAN side packet input units may be used. It may be a number. Further, if there are a plurality of WAN side packet output units, the number of WAN packet input units may be one and packets from one WAN side packet input unit may be transmitted to the decapsulation device 623.

  The virtual leased line device of the embodiment described above can be realized by a computer and a program, and the program can be recorded on a recording medium or provided through a network.

  As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

It is a figure which shows the example in which the apparatus A and the apparatus B are connected by three WAN lines. FIG. 6 is a diagram showing some combinations of connections of devices A and B. It is a figure which shows the example of the actual zone | band between each measured port. It is a figure which shows the combination of a WAN side port. It is the figure showing the flow of the packet data in the Example of this invention. It is an internal schematic diagram of the virtual leased line device of the embodiment of the present invention. It is a table | surface which shows the real band between each port measured in the Example of this invention. It is a figure which shows the table | surface which the control part 615 produces. It is a figure which shows the mode of a connection with the other party virtual private line apparatus in the case of the combination 4 of the combination table 801 of FIG. It is a figure which shows the basic flowchart of the connection method of the virtual leased line apparatus of the Example of this invention.

Explanation of symbols

501 ... VPN device A, 502 ... VPN device B, 503 ... IP network (WAN), 540 ... Details of IP packet, 541 ... IP header, 542 ... Payload, 550 ... Details of encapsulated packet, 551 ... Encapsulated header, 552 ... Normal IP packet, 553 ... Details of encapsulation header 551, 554 ... Further details of encapsulation header 553, 555 ... IP header, 556 ... Sequence number, 557 ... label, 560 ... Details of reconstructed packet, 561 ... IP header, 562 ... payload, 601 ... virtual leased line device, 611 ... LAN side packet input unit, 612 ... packet memory, 613 ... encapsulation device, 614 ... selector, 615 ... control unit, 616 ... WAN side packet Output unit (G1out), 617 ... WAN side packet output unit G2out), 618 ... WAN side packet output unit (G3out), 619 ... WAN side packet input unit (G1in), 620 ... WAN side packet input unit (G2in), 621 ... WAN side packet input unit (G3in), 622 ... Communication Quality measurement unit, 623 ... decapsulation device, 624 ... packet memory, 625 ... LAN side packet output unit, 626 ... storage device used for storing history data, etc., 602 ... partner virtual leased line device, 631 ... WAN side Packet input unit (B1in), 632 ... WAN side packet input unit (B2in), 633 ... WAN side packet input unit (B3in), 634 ... WAN side packet output unit (B1out), 635 ... WAN side packet output unit (B2out) 636 ... WAN side packet output section (B3out), 801 ... Combination table 802 ... Packet distribution ratio table 803 ... destination selection table

Claims (10)

A virtual leased line device for connecting a plurality of WAN side packet output units to a plurality of WAN side packet input units of a destination virtual leased line device,
A combination to be connected is determined based on a measurement result obtained by measuring communication quality with respect to a combination of a plurality of WAN side packet output units and a plurality of WAN side packet input units of a partner virtual leased line device, and each combination is determined based on the determined combination. A control unit that determines a ratio of packets to be transmitted to the WAN side packet output unit and a WAN side packet input unit of the destination virtual dedicated line device to be transmitted from each WAN side packet output unit;
A selector that distributes and transmits the flow identifier grant packet assigned the flow identifier in the flow identifier grant unit to the plurality of WAN side packet output units at a rate determined by the control unit;
A plurality of WAN-side packet output units that transmit the flow identifier giving packets received from the selector to the WAN-side packet input unit of the counterpart virtual dedicated line device determined by the control unit;
A virtual leased line device comprising: The virtual leased line device according to claim 1,
A virtual leased line device comprising: a plurality of WAN side packet input units for transmitting flow identifier-added packets received from a plurality of WAN side packet output units of a counterpart virtual leased line device to a flow identifier removing unit. The virtual leased line device according to claim 2,
The packet sent from the LAN side packet input unit is temporarily stored in the packet memory, and then sent to the flow identifier adding unit.
The virtual leased line apparatus characterized in that the packet sent from the flow identifier removing unit is temporarily stored in a packet memory and then transmitted to the LAN side packet output unit. The virtual leased line device according to claim 2 or 3,
All the own addresses of the plurality of WAN side packet input units and output units are set, one of the destination addresses is set in one of the plurality of WAN side packet input units and output units, and the destination address is set A virtual leased line apparatus characterized by skipping a probe packet to a destination and establishing a virtual leased line connection by connecting each WAN line based on address information sent from a partner leased line apparatus. The virtual leased line device according to any one of claims 1 to 4,
Even after the connection with the partner virtual leased line device is set based on the combination determined by the control unit, the communication quality is continuously measured, and the combination to be connected is updated based on the measurement result. Virtual leased line device. The virtual leased line device according to any one of claims 1 to 5,
The communication quality measurement result and / or the determined combination is stored in the storage device as a history, and based on the communication quality measurement result and / or the determined combination stored in the storage device at the subsequent startup. A virtual leased line device that can be used immediately after startup. The virtual leased line device according to any one of claims 1 to 6,
When the required communication quality is the size of the bandwidth, a combination that maximizes the total bandwidth is adopted, and the ratio of the bandwidth of each WAN line to the total bandwidth is transmitted to each WAN-side packet output unit. A virtual leased line apparatus characterized by determining a ratio of packets to be transmitted. The virtual leased line device according to any one of claims 1 to 6,
A virtual leased line apparatus characterized by adopting a combination that minimizes the maximum delay value of each WAN line when the required communication quality is real-time. A connection method of a virtual leased line device for connecting a plurality of WAN side packet output units to a plurality of WAN side packet input units of a counterpart virtual leased line device,
The virtual leased line device includes a control unit, a flow identifier assigning unit, a selector, and a plurality of WAN side packet output units,
The control unit determines a combination to be connected based on a measurement result obtained by measuring communication quality with respect to a combination of a plurality of WAN side packet output units and a plurality of WAN side packet input units of a destination virtual dedicated line device. Determine the ratio of packets to be transmitted to each WAN side packet output unit based on the combination and the WAN side packet input unit of the destination virtual private line device to be transmitted from each WAN side packet output unit,
The selector transmits the flow identifier grant packet assigned the flow identifier by the flow identifier grant unit to the plurality of WAN side packet output units at a rate determined by the control unit,
The plurality of WAN side packet output units transmit the flow identifier giving packet received from the selector to the WAN side packet input unit of the counterpart virtual leased line device determined by the control unit,
A method for connecting a virtual leased line device, characterized in that:   The program for functioning a computer as a virtual leased line apparatus of any one of Claim 1 thru | or 8.

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