JP5462197B2 - Migration control device, packet transfer system, migration control method and program - Google Patents

Description

  The present invention relates to a migration control apparatus, a packet transfer system, a migration control method, and a program for controlling migration of a service providing function that performs predetermined processing on a packet.

  In the IP (Internet Protocol) network, address translation such as NAT (Network Address Translation) and NAPT (Network Address Port Translation), PPPoE (Point to Point over Internet), PPPoE (Point to Point over Internet). Services such as VoIP (Voice over Internet Protocol), WWW (World Wide Web), and video distribution are provided by performing predetermined processing such as addition of a header for tunneling, etc. on a packet.

  In order to realize the provision of these services, a service providing function that accepts a packet output from a packet transfer device such as a router, converts the address of the accepted packet, and adds a header to the accepted packet. The provided service providing apparatus is used.

  Here, when the service providing function is updated or when the service providing apparatus is maintained, the service providing apparatus needs to be stopped for a certain period.

  In addition, in the case of a service providing device having a service providing function for providing a service with a low usage rate, the service providing function is transferred to another service providing device or the like during a time period in which the usage rate is expected to decrease further, such as at night. May be aggregated. As a result, the number of service providing apparatuses in operation can be reduced, and operation costs can be saved.

  The provision of services as described above usually requires high reliability. Therefore, when the service providing apparatus is stopped for a certain period, it is necessary to transfer the service providing function of the service providing apparatus to another service providing apparatus or the like while the service providing function is enabled.

  For example, Non-Patent Document 1 discloses a method of migrating a virtual machine to another apparatus for each OS (Operating System) in a technique for operating a virtual machine on one apparatus.

  With the method disclosed in Non-Patent Document 1, it is possible to migrate at high speed while maintaining the state of the virtual machine.

<http://www.vmware.com/jp/products/vmotion/index.html> (VM Homepage <Search December 7, 2010>)

  If the method disclosed in Non-Patent Document 1 described above is used, it seems that the service providing function can be transferred to another service providing apparatus or the like while the service providing function is enabled.

  Here, when migrating the service providing function, by changing the routing information of the packet transfer device, the output destination of the packet from the packet transfer device is changed from the source service providing device to the destination service providing device. I have to do it.

  In this case, if the routing information of the packet forwarding device is changed after the transition of the service providing function is completed, the service providing function is not enabled from the start of the transition of the service providing function until the routing information is changed. The packet is output to the original service providing apparatus. Therefore, there is a problem that packet loss occurs.

  On the other hand, if the transition of the service provision function is started after changing the routing information of the packet transfer device, the service provision function is not enabled until the transition of the service provision function is completed after the routing information is changed A packet is output to the service providing apparatus at the transfer destination. Therefore, there is still a problem that packet loss occurs.

  An object of the present invention is to provide a migration control device, a packet transfer system, a migration control method, and a program that enable a migration of a service providing function without causing packet loss.

In order to achieve the above object, the migration control device of the present invention receives a packet output from the packet transfer device and provides a service providing function for performing predetermined processing on the received packet from the first service providing device to the second. The packet transfer device, the first and second service providing devices, the buffer device that can store the packets, and the packets that have undergone the predetermined processing are transferred at predetermined time intervals. A transition control device that controls the output device that outputs in
Before the transition is started, the output destination of the packet from the packet transfer device is changed from the first service providing device to the second service providing device, and the packet transfer device outputs the packet. The packet output from the packet transfer device is accumulated in the buffer device until the transition is completed after the destination is changed, and when the transition is completed, the predetermined processing is performed on the accumulated packet. To instruct the second service providing apparatus.

In order to achieve the above object, a packet transfer system of the present invention includes a packet transfer device and a service providing function for receiving a packet output from the packet transfer device and performing a predetermined process on the received packet. A packet transfer system having a first service providing device and a second service providing device, and capable of transferring the service providing function from the first service providing device to the second service providing device,
A buffer device capable of storing packets;
The packet transfer apparatus changes the output destination of the packet from the first service providing apparatus to the second service providing apparatus before the transition is started,
The buffer device accumulates the packets output from the packet transfer device until the transition is completed after the packet output destination is changed in the packet transfer device,
When the transition is completed, the second service providing apparatus performs the predetermined processing on the accumulated packets.

In order to achieve the above object, the migration control method of the present invention has a service providing function for receiving a packet output from a packet transfer device and performing a predetermined process on the received packet from the first service providing device. When shifting to the second service providing device, the packet transfer device, the first and second service providing devices, a buffer device capable of storing packets, and a packet subjected to the predetermined processing are set to a predetermined value. A transition control method in a transition control device for controlling an output device that outputs at time intervals,
A process of changing the output destination of the packet from the packet transfer device from the first service providing device to the second service providing device before the transition is started;
A process of accumulating packets output from the packet transfer device in the buffer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
A process for instructing the second service providing apparatus to perform the predetermined process on the accumulated packets when the transfer is completed.

In order to achieve the above object, the migration control method of the present invention includes a packet transfer device and a service providing function for receiving a packet output from the packet transfer device and performing a predetermined process on the received packet. A first service providing device; an output device that outputs the packets subjected to the predetermined processing at predetermined time intervals; a buffer device that can store the packets; and a second service providing device; A transfer control method in a packet transfer system capable of transferring the service providing function from one service providing apparatus to the second service providing apparatus,
A process of changing the packet output destination from the first service providing apparatus to the second service providing apparatus before the packet transfer apparatus starts the transition;
The buffer device stores the packet output from the packet transfer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
The second service providing apparatus includes a process of performing the predetermined process on the accumulated packets when the transition is completed.

In order to achieve the above object, the program of the present invention receives a packet output from the packet transfer device and performs a service providing function for performing a predetermined process on the received packet from the first service providing device to the second. The packet transfer device, the first and second service providing devices, the buffer device that can store the packets, and the packets that have undergone the predetermined processing are transferred at predetermined time intervals. In the transition control device that controls the output device that outputs in
A function of changing an output destination of a packet from the packet transfer apparatus from the first service providing apparatus to the second service providing apparatus before the transition is started;
A function of storing the packet output from the packet transfer device in the buffer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
When the transition is completed, a function of instructing the second service providing apparatus to perform the predetermined processing on the accumulated packets is realized.

  Since the present invention is configured as described above, the service providing function can be transferred without causing packet loss.

It is a block diagram which shows an example of a structure of 1st Embodiment of the packet transfer system of this invention. 2 is a flowchart for explaining an operation when a service providing function is shifted in the packet transfer system shown in FIG. 1. It is a block diagram which shows the other structural example of 1st Embodiment of the packet transfer system of this invention. It is a block diagram which shows the structure of 2nd Embodiment of the packet transfer system of this invention. 5 is a flowchart for explaining an operation in a case where a service providing function is shifted in the packet transfer system shown in FIG. 4. It is a figure for demonstrating an example of the change of the time interval which a packet is output in the operation | movement shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing an example of the configuration of the first embodiment of the packet transfer system of the present invention.

  As shown in FIG. 1, the packet transfer system according to the present embodiment includes packet transfer apparatuses 10 and 20, a packet transfer control apparatus 30, a service providing apparatus 40 that is a first service providing apparatus, and a second service providing apparatus. The service providing device 50 and the transition control device 60 are provided.

  The packet transfer device 10 is, for example, a router having a function of transferring a packet, and includes a packet transfer unit 11, a routing information DB (Data Base) 12, and ports 13 to 15 for inputting and outputting packets. The packet transfer device 20 is a router or the like having a function of transferring a packet, like the packet transfer device 10, and includes a packet transfer unit 21, a routing information DB 22, and ports 23 to 25 for inputting and outputting packets. . Here, the number of ports included in the packet transfer apparatuses 10 and 20 is three, but the number of ports included in the packet transfer apparatuses 10 and 20 is not limited to three.

  Details of the configuration of the packet transfer apparatus 10 will be described below, but the packet transfer apparatus 20 has the same configuration.

  The routing information DB 12 stores routing information in which a packet destination is associated with a port that outputs the packet among the ports 13 to 15.

  The packet transfer unit 11 receives input of packets via the ports 13 to 15. Then, the packet transfer unit 11 searches the routing information stored in the routing information DB 12 for a port corresponding to the destination of the received packet among the ports 13 to 15. The packet transfer unit 11 outputs the received packet from the searched port.

  The packet transfer control device 30 includes a route calculation unit 31, a routing information setting unit 32, and a topology information DB 33.

  The topology information DB 33 stores topology information indicating the configuration of the network including the packet transfer apparatuses 10 and 20 and the service providing apparatuses 40 and 50.

  The route calculation unit 31 performs route calculation between devices in the network including the packet transfer devices 10 and 20 and the service providing devices 40 and 50 based on the topology information stored in the topology information DB 33.

  The routing information setting unit 32 sets and changes the routing information stored in the routing information DBs 12 and 22 of the packet transfer apparatuses 10 and 20 based on the calculation result in the route calculation unit 31.

  The service providing device 40 has a service providing function that receives a packet output from the packet transfer device 10 and performs predetermined processing necessary for providing the service, such as address conversion and addition of a header, on the received packet. Specifically, the service providing device 40 includes a buffer unit 41 and a service providing unit 42. Similarly, the service providing device 50 includes a buffer unit 51 that is a buffer device, and a service providing unit 52.

  Details of the configuration of the service providing apparatus 40 will be described below, but the service providing apparatus 50 has the same configuration.

  The buffer unit 41 receives a packet output from the packet transfer apparatus 10. And the buffer part 41 accumulate | stores the received packet according to the instruction | indication from the transfer control apparatus 60 mentioned later.

  The service providing unit 42 performs a predetermined process on the packet received by the buffer unit 41. The service providing unit 42 functions as an output device, and outputs a packet that has been subjected to predetermined processing to the packet transfer device 20.

  In the present embodiment, it is assumed that the service providing apparatus 40 receives a packet output from the packet transfer apparatus 10 and performs a predetermined process on the received packet. Then, when it is necessary to stop the service providing apparatus 40 for a certain period by updating the service providing function of the service providing apparatus 40 or maintaining the service providing apparatus 40, the service providing function from the service providing apparatus 40 to the service providing apparatus 50 is provided. Shall be migrated. With this transition, the service providing device 50 has the same service providing function as the service providing device 40.

  The transition control device 60 includes a parameter calculation unit 61, an operation instruction unit 62, and a parameter information DB 63.

  The parameter information DB 63 stores information necessary for transferring a service providing function between the service providing apparatus 40 and the service providing apparatus 50 as parameter information. The parameter information is, for example, the time required for the transition of the service providing function.

  Based on the parameter information stored in the parameter information DB 63, the parameter calculation unit 61 determines a control schedule for controlling the service providing devices 40 and 50, the packet transfer device 10, and the like when performing the service providing function. The control schedule is stored in the packet transfer device 10, for example, the timing at which the buffer unit 51 of the service providing device 50 starts accumulation of packets output from the packet transfer device 10, the timing at which the transition of the service providing function starts, or the like. The timing for changing the routing information is included. Parameter calculation unit 61 then outputs control schedule information indicating the determined control schedule to operation instruction unit 62.

  The operation instruction unit 62 has a timer (not shown) that measures time. The operation instruction unit 62 receives the control schedule information output from the parameter calculation unit 61. Then, the operation instruction unit 62 transmits various instructions to the service providing devices 40 and 50, the packet transfer device 10, and the like based on the control schedule indicated by the received control schedule information. Specifically, the operation instruction unit 62 transmits to the packet transfer control device 30 a route change instruction that instructs to change the output destination of the packet from the packet transfer device 10. In addition, the operation instruction unit 62 transmits an accumulation start instruction for instructing the start of packet accumulation to the service providing apparatus 50. In addition, the operation instruction unit 62 transmits a transition start instruction for instructing the start of transition of the service providing function to the service providing apparatuses 40 and 50. In addition, the operation instruction unit 62 transmits to the service providing apparatus 50 an accumulation stop instruction that instructs to stop accumulation of packets and to perform predetermined processing on the accumulated packets.

  The operation of the packet transfer system configured as described above will be described below. Here, when a predetermined process is performed by the service providing apparatus 40 on the packet of the destination A output from the packet transfer apparatus 10, the service providing function is transferred from the service providing apparatus 40 to the service providing apparatus 50. Will be described.

Note that the topology information DB 33 of the packet transfer control device 30 stores the following information indicating that the devices are connected or between the devices and the network as topology information.
Between the packet transfer apparatus 10 and the service providing apparatus 40 Between the packet transfer apparatus 10 and the service providing apparatus 50 Between the packet transfer apparatus 20 and the service providing apparatus 40 The packet transfer apparatus 20 and the service providing apparatus 50 Between the service providing device 40 and the service providing device 50, between the packet transfer device 20 and the network for reaching A. In the parameter information DB 63 of the transition control device 60, “service providing function Information that “the time required for migration is 120 ms” is stored as parameter information.

  The routing information DB 12 of the packet transfer apparatus 10 stores information “Destination A and port 14 correspond” as routing information.

  FIG. 2 is a flowchart for explaining the operation when the service providing function is shifted in the packet transfer system shown in FIG.

  First, the parameter calculation unit 61 of the transition control device 60 determines a control schedule based on the parameter information stored in the parameter information DB 63 (step S1).

  Parameter calculation unit 61 then outputs control schedule information indicating the determined control schedule to operation instruction unit 62.

  The operation instruction unit 62 that has received the control schedule information output from the parameter calculation unit 61 transmits an accumulation start instruction to the service providing apparatus 50 based on the control schedule indicated by the received control schedule information.

  In addition, the operation instruction unit 62 transmits to the packet transfer control device 30 a route change instruction for changing the output destination of the packet from the packet transfer device 10 from the service providing device 40 to the service providing device 50.

  The route calculation unit 31 of the packet transfer control device 30 that has received the route change instruction transmitted from the migration control device 60 services the output destination of the packet from the packet transfer device 10 based on the topology information stored in the topology information DB 33. Route calculation for changing from the providing device 40 to the service providing device 50 is performed.

  And the routing information setting part 32 changes the routing information memorize | stored in routing information DB12 of the packet transfer apparatus 10 based on the calculation result in the route calculation part 31 (step S2). Specifically, the port corresponding to destination A is changed from port 14 to port 15.

  As a result, the packet transfer unit 11 of the packet transfer device 10 outputs the packet of the destination A from the port 15, that is, the port on the service providing device 50 side.

  Then, the buffer unit 51 of the service providing apparatus 50 starts accumulation of the packet of the destination A (step S3).

  Further, the operation instruction unit 62 transmits a shift instruction to the service providing apparatuses 40 and 50. At the same time, the operation instruction unit 62 starts a timer (step S4).

  The service providing units 42 and 52 of the service providing devices 40 and 50 that have received the migration instruction transmitted from the migration control device 60 start migrating the service providing function from the service providing unit 42 to the service providing unit 52 (step S5). ).

  Next, the operation instruction unit 62 confirms whether the elapsed time of the timer has exceeded 120 ms, that is, whether the time required for the transition of the service providing function has been exceeded (step S6).

  As a result of the confirmation in step S6, when the elapsed time of the timer does not exceed 120 ms, the operation transitions to the operation of step S6, and the operation instruction unit 62 repeats confirmation of the elapsed time of the timer.

  On the other hand, if the elapsed time of the timer exceeds 120 ms as a result of the confirmation in step S <b> 6, the operation instruction unit 62 transmits an accumulation stop instruction to the service providing apparatus 50.

  In the service providing device 50 that has received the accumulation stop instruction transmitted from the migration control device 60, the buffer unit 51 stops the accumulation of the received packet (step S7).

  Then, the service providing unit 52 of the service providing device 50 performs a predetermined process on the packets stored in the buffer unit 51 and outputs the packets to the packet transfer device 20 (step S8).

  Thereafter, the buffer unit 51 does not accumulate the packets output from the packet transfer device 10, and the service providing unit 52 sequentially performs a predetermined process on the packets received by the buffer unit 51 and proceeds to the packet transfer device 20. Output.

  As described above, in the present embodiment, the transition control device 60 changes the output destination of the packet from the packet transfer device 10 from the service providing device 40 to the service providing device 50 before the transition of the service providing function is started. The transition control device 60 further transfers the packet output from the packet transfer device 10 to the service providing device 50 after the packet output device 10 changes the output destination of the packet until the transition of the service providing function is completed. Accumulate. Then, when the transition of the service providing function is completed, the transition control device 60 instructs the service providing device 50 to perform a predetermined process on the accumulated packets.

  As a result, the service providing function can be shifted without causing packet loss.

  In the present embodiment, the configuration in which the service providing apparatus includes the buffer unit has been described. However, as illustrated in FIG. 3 described below, the buffer unit may be provided as a buffer device separately from the service providing apparatus.

  FIG. 3 is a block diagram showing another configuration example of the first embodiment of the packet transfer system of the present invention.

  In the example illustrated in FIG. 3, the service providing apparatus includes only the service providing unit, and a buffer device 101 that can store packets is provided separately from the service providing apparatus.

(Second Embodiment)
FIG. 4 is a block diagram showing the configuration of the second embodiment of the packet transfer system of the present invention.

  As shown in FIG. 4, the packet transfer system according to the present embodiment includes packet transfer apparatuses 10 and 20, a packet transfer control apparatus 30, a service providing apparatus 70 that is a first service providing apparatus, and a second service providing apparatus. The service providing device 80 and the transition control device 90 are provided.

  As shown in FIG. 4, the service providing apparatus 70 of this embodiment includes a buffer unit 71, a service providing unit 72, and an output interval adjusting unit 73. That is, the service providing apparatus 70 is different from the service providing apparatus 40 in the first embodiment described above in that it includes an output interval adjusting unit 73. The service providing apparatus 80 is different from the service providing apparatus 50 in the first embodiment described above in that an output interval adjusting unit 83 is provided.

  Details of the configuration of the service providing apparatus 70 will be described below, but the service providing apparatus 80 has the same configuration.

  The buffer unit 71 receives the packet output from the packet transfer device 10. And the buffer part 71 accumulate | stores the received packet, when there exists an instruction | indication from the transfer control apparatus 90 mentioned later.

  The service providing unit 72 performs a predetermined process on the packet received by the buffer unit 71.

  The output interval adjustment unit 73 functions as an output device, and outputs a packet, which has been subjected to predetermined processing by the service providing unit 72, to the packet transfer device 20 at a time interval instructed by the transition control device 90 described later. To do.

  As shown in FIG. 4, the migration control device 90 of this embodiment includes a parameter calculation unit 91, an operation instruction unit 92, and a parameter information DB 93.

  The parameter information DB 93 stores information necessary for transferring the service providing function between the service providing apparatus 40 and the service providing apparatus 50 as parameter information. The parameter information is, for example, a time required for the transition of the service providing function or a time interval at which the service providing apparatus outputs a packet at a normal time other than the transition of the service providing function.

  Based on the parameter information stored in the parameter information DB 93, the parameter calculation unit 91 determines a control schedule for controlling the service providing devices 70 and 80, the packet transfer device 10 and the like when performing the service providing function. In addition to what has been described in the first embodiment, the control schedule includes a time interval at which the service providing apparatus outputs a packet when the service providing function is shifted. Parameter calculation unit 91 then outputs control schedule information indicating the determined control schedule to operation instruction unit 92.

  The operation instruction unit 92 has a timer (not shown) that measures time. The operation instruction unit 92 receives the control schedule information output from the parameter calculation unit 91. Then, the operation instruction unit 92 transmits various instructions to the service providing devices 70 and 80, the packet transfer device 10, and the like based on the control schedule indicated by the received control schedule information. In addition to the instruction described in the first embodiment, the operation instruction unit 92 returns an output interval change instruction for instructing a change in a time interval for outputting a packet, and returns the changed time interval to a normal time interval. An output interval change stop instruction or the like is sent to the service providing apparatuses 70 and 80.

  The configurations and operations of the packet transfer apparatuses 10 and 20 and the packet transfer control apparatus 30 in the present embodiment are the same as those described in the first embodiment.

  The operation of the packet transfer system configured as described above will be described below. Here, in the same way as in the first embodiment described above, when a predetermined process is performed by the service providing apparatus 70 on the packet of the destination A output from the packet transfer apparatus 10, the service providing apparatus 70 provides a service. A case where the service providing function is transferred to the providing device 80 will be described.

Note that the topology information DB 33 of the packet transfer control device 30 stores the following information indicating that the devices are connected or between the devices and the network as topology information.
Between the packet transfer apparatus 10 and the service providing apparatus 70 Between the packet transfer apparatus 10 and the service providing apparatus 80 Between the packet transfer apparatus 20 and the service providing apparatus 70 The packet transfer apparatus 20 and the service providing apparatus 80 Between the service providing device 70 and the service providing device 80, between the packet transfer device 20 and the network for reaching A. Also, the parameter information DB 93 of the migration control device 90 includes the following two Information is stored as parameter information.
・ Time required for transition of service provision function: 120 ms
-Time interval of packets output from the service providing apparatus in normal time: 20 ms
The routing information DB 12 of the packet transfer apparatus 10 stores information “Destination A and port 14 correspond” as routing information.

  FIG. 5 is a flowchart for explaining the operation in the case of shifting the function of providing a service in the packet transfer system shown in FIG. FIG. 6 is a diagram for explaining an example of a change in a time interval at which a packet is output in the operation shown in FIG.

  First, the parameter calculation unit 91 of the transition control device 90 determines a control schedule as shown in the following (A) to (D) based on the parameter information stored in the parameter information DB 93 (step S21).

(A) Time interval specified by an output interval change instruction to be transmitted to the service providing apparatus 70: 40 ms
Until the transition of the service providing function is completed, the time interval for outputting the packets is made longer than the normal time interval (20 ms) so that the service providing device 70 can continuously output the packets. As a result, it is possible to suppress packet delay and delay fluctuation caused by the packet delay. Here, the packet is output at a constant time interval (40 ms), but by gradually increasing the time interval for outputting the packet from the normal time interval (20 ms), Delay and delay fluctuation can be further suppressed.

(B) Timing to transmit accumulation start instruction, route change instruction, and transition instruction: 120 ms after transmission of output interval change instruction to service providing apparatus 70. Similarly to (A) above, transition of service providing function is also performed. This is because the service providing apparatus 70 can continuously output packets until the process is completed. Here, it is calculated as 120 ms from the time when 3 packets are accumulated at a time interval of 40 ms.

(C) Time interval specified by an output interval change instruction to be transmitted to the service providing apparatus 80: 10 ms
In order to be able to output the packets stored in the buffer unit 81 as soon as possible, the time interval for outputting the packets is shorter than the normal time interval (20 ms). Thereby, packet delay and delay fluctuation can be suppressed. Here, the packets are output at a constant time interval (10 ms). However, according to the number of packets that are not output among the packets stored in the buffer unit 81, the time interval at which the packets are output is 10 ms. By gradually increasing from the normal time interval to 20 ms, packet delay and delay fluctuation can be further suppressed.

(D) Timing of transmitting an output interval change stop instruction: 360 ms after the output interval change instruction is transmitted to the service providing apparatus 70. This is because all packets stored in the buffer unit 81 during the transition of the service providing function are transmitted. This is the time required for output.

  Then, the parameter calculation unit 91 outputs control schedule information indicating the control schedule determined as described in (A) to (D) above to the operation instruction unit 92.

  The operation instruction unit 92 that has received the control schedule information output from the parameter calculation unit 91 instructs to change the time interval for outputting packets to 40 ms based on the control schedule indicated by the received control schedule information. The instruction is transmitted to the service providing apparatus 70. At the same time, the operation instruction unit 92 starts a timer (step S22).

  The output interval adjustment unit 73 of the service providing device 70 that has received the output interval change instruction transmitted from the migration control device 90 processes the packet that has been subjected to the predetermined processing by the service providing unit 72 as shown in FIG. The data is output toward the packet transfer apparatus 20 at an interval of 40 ms (step S23).

  Next, the operation instruction unit 92 checks whether the elapsed time of the timer has exceeded 120 ms (step S24).

  As a result of the confirmation in step S24, when the elapsed time of the timer does not exceed 120 ms, the operation transitions to the operation of step S24, and the operation instruction unit 92 repeats confirmation of the elapsed time of the timer.

  On the other hand, when the elapsed time of the timer exceeds 120 ms as a result of the confirmation in step S24, the operation instruction unit 92 transmits an accumulation start instruction to the service providing apparatus 80.

  In addition, the operation instruction unit 92 transmits to the packet transfer control device 30 a route change instruction for changing the output destination of the packet from the packet transfer device 10 from the service providing device 70 to the service providing device 80.

  The route calculation unit 31 of the packet transfer control device 30 that has received the route change instruction transmitted from the migration control device 90 services the output destination of the packet from the packet transfer device 10 based on the topology information stored in the topology information DB 33. Route calculation for changing from the providing device 70 to the service providing device 80 is performed.

  And the routing information setting part 32 changes the routing information memorize | stored in routing information DB12 of the packet transfer apparatus 10 based on the calculation result in the route calculation part 31 (step S25). Specifically, the port corresponding to destination A is changed from port 14 to port 15.

  As a result, the packet transfer unit 11 of the packet transfer apparatus 10 outputs the packet of the destination A from the port 15, that is, the port on the service providing apparatus 80 side.

  Then, the buffer unit 81 of the service providing apparatus 80 starts accumulation of the packet of the destination A (Step S26).

  In addition, the operation instruction unit 92 transmits a migration instruction to the service providing apparatuses 70 and 80.

  The service providing units 72 and 82 of the service providing devices 70 and 80 that have received the migration instruction transmitted from the migration control device 90 start the transition of the service providing function from the service providing unit 72 to the service providing unit 82 (step S27). .

  Next, the operation instruction unit 62 confirms whether or not the elapsed time of the timer has exceeded 240 ms (step S28).

  As a result of the confirmation in step S28, when the elapsed time of the timer does not exceed 240 ms, the operation transitions to the operation of step S28, and the operation instruction unit 92 repeats confirmation of the elapsed time of the timer.

  On the other hand, if the elapsed time of the timer exceeds 240 ms as a result of the confirmation in step S28, the operation instruction unit 92 transmits an accumulation stop instruction to the service providing apparatus 80.

  In the service providing apparatus 80 that has received the accumulation stop instruction transmitted from the migration control apparatus 90, the buffer unit 81 stops accumulating the received packet (step S29).

  Then, the service providing unit 82 of the service providing apparatus 80 performs a predetermined process on the packets stored in the buffer unit 81 (step S30).

  Next, the operation instruction unit 92 transmits an output interval change instruction to change the time interval for outputting packets to 10 ms to the service providing apparatus 80.

  The output interval adjustment unit 83 of the service providing apparatus 80 that has received the output interval change instruction transmitted from the migration control apparatus 90 converts the packet that has undergone the predetermined processing in step S30 into a time interval of 10 ms as shown in FIG. Is output to the packet transfer apparatus 20 (step S31).

  Next, the operation instruction unit 92 confirms whether the elapsed time of the timer has exceeded 360 ms (step S32).

  As a result of the confirmation in step S32, when the elapsed time of the timer does not exceed 360 ms, the operation transitions to the operation of step S32, and the operation instruction unit 92 repeats confirmation of the elapsed time of the timer.

  On the other hand, as a result of the confirmation in step S32, when the elapsed time of the timer exceeds 360 ms, the operation instruction unit 92 transmits an output interval change stop instruction to the service providing apparatus 80.

  The output interval adjustment unit 83 of the service providing device 80 that has received the output interval change stop instruction transmitted from the transition control device 90 transfers the packet that has been subjected to the predetermined processing by the service providing unit 82 at a time interval of 20 ms. It outputs toward the apparatus 20 (step S33).

  As described above, in the present embodiment, the migration control device 90 changes the output destination of the packet from the packet transfer device 10 from the service providing device 70 to the service providing device 80 before the transition of the service providing function is started. The transition control device 90 further sends the packet output from the packet transfer device 10 to the service providing device 80 after the packet output destination is changed in the packet transfer device 10 until the transition of the service providing function is completed. Accumulate. Then, when the transition of the service providing function is completed, the transition control device 90 instructs the service providing device 80 to perform predetermined processing on the accumulated packets.

  As a result, the service providing function can be shifted without causing packet loss.

  Further, in this embodiment, the transition control device 90 sets the time interval for outputting the accumulated packets subjected to the predetermined processing in the service providing device 80 after the transition of the service providing function is completed to the normal time. Make it shorter than the interval. Further, the transition control device 90 makes the time interval at which the service providing device 70 outputs a packet longer than the normal time interval before a predetermined time (120 ms) when the transition of the service providing function is started.

  This makes it possible to suppress packet delay and delay fluctuation. Specifically, it is possible to suppress deterioration in communication quality when shifting to a service providing function that provides a service that requires a high real-time property, such as IP telephone and moving image distribution.

  In the present embodiment, the configuration in which the service providing apparatus includes the buffer unit and the output interval adjustment unit has been described. However, as in the configuration illustrated in FIG. 3, the buffer unit is provided as a buffer device separately from the service providing apparatus. It is good also as a structure. The output interval adjustment unit may be provided as an output device separately from the service providing device.

  In the two embodiments described above, the configuration in which the migration control device is provided separately from the service providing device, the packet transfer device, and the like has been described. Instead of such a configuration, it is also possible to autonomously decentralize the service provision function by providing the function provided by the transition control device in the service providing device or the packet transfer device without providing the transition control device. is there.

  In the present invention, the processing in the migration control device is recorded on a recording medium readable by the migration control device, in addition to the processing realized by the dedicated hardware described above. The program recorded on the recording medium may be read by the migration control device and executed. The recording medium readable by the migration control device refers to a HDD incorporated in the migration control device in addition to a transferable recording medium such as a flexible disk, a magneto-optical disk, a DVD, and a CD.

10, 20 Packet transfer device 11, 21 Packet transfer unit 12, 22 Routing information DB
13 to 15, 23 to 25 Port 30 Packet transfer control device 31 Route calculation unit 32 Routing information setting unit 33 Topology information DB
40, 50, 70, 80 Service providing device 41, 51, 71, 81 Buffer unit 42, 52, 72, 82 Service providing unit 60 Migration control device 61 Parameter calculation unit 62 Operation instruction unit 63 Parameter information DB
73, 83 Output interval adjustment unit 101 Buffer device

Claims (10)

When the service providing function of receiving a packet output from the packet transfer device and performing a predetermined process on the received packet is shifted from the first service providing device to the second service providing device, A transition control device for controlling the first and second service providing devices, a buffer device capable of storing packets, and an output device for outputting the packets subjected to the predetermined processing at predetermined time intervals; ,
Before the transition is started, the output destination of the packet from the packet transfer device is changed from the first service providing device to the second service providing device, and the packet transfer device outputs the packet. The packet output from the packet transfer device is accumulated in the buffer device until the transition is completed after the destination is changed, and when the transition is completed, the predetermined processing is performed on the accumulated packet. and instructing said second service providing device so,
After the transition is completed, the output device causes the time interval for outputting the accumulated packets subjected to the predetermined processing to be shorter than the predetermined time interval, and thereafter the predetermined processing is performed. Transition that gradually increases the time interval for outputting the accumulated packet that has undergone the predetermined processing to the predetermined time interval according to the number of packets that have not been output among the accumulated packets that have been applied Control device. The transfer control device according to claim 1 ,
The transition in which the time interval for the output device to output the packet subjected to the predetermined processing is gradually increased from the predetermined time interval until the transition is completed from the predetermined time before the transition starts. Control device. A packet transfer apparatus, a first service providing apparatus having a service providing function for receiving a packet output from the packet transfer apparatus and performing a predetermined process on the received packet; and a second service providing apparatus. A packet transfer system capable of transferring the service providing function from the first service providing apparatus to the second service providing apparatus,
A buffer device capable of storing packets;
The packet transfer apparatus changes the output destination of the packet from the first service providing apparatus to the second service providing apparatus before the transition is started,
The buffer device accumulates the packets output from the packet transfer device until the transition is completed after the packet output destination is changed in the packet transfer device,
The second service providing apparatus, when the transition is complete, and facilities the predetermined processing to the stored packets,
An output device that outputs the packets subjected to the predetermined processing at predetermined time intervals;
After the transition is completed, the output device makes the time interval for outputting the accumulated packets subjected to the predetermined processing shorter than the predetermined time interval, and thereafter performs the predetermined processing. Packet transfer for gradually increasing the time interval for outputting the accumulated packets subjected to the predetermined processing to the predetermined time interval according to the number of packets that have not been output among the accumulated packets system. The packet transfer system according to claim 3 , wherein
The output device is a packet that gradually increases a time interval for outputting a packet subjected to the predetermined process from a predetermined time before the transition is started until the transition is completed. Transfer system. When the service providing function of receiving a packet output from the packet transfer device and performing a predetermined process on the received packet is shifted from the first service providing device to the second service providing device, Transition control in a transition control device that controls the first and second service providing devices, a buffer device capable of storing packets, and an output device that outputs the packets subjected to the predetermined processing at predetermined time intervals A method,
A process of changing the output destination of the packet from the packet transfer device from the first service providing device to the second service providing device before the transition is started;
A process of accumulating packets output from the packet transfer device in the buffer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
When the transition is completed, a process for instructing the second service providing apparatus to perform the predetermined process on the accumulated packets;
After the transition is completed, the output device causes the time interval for outputting the accumulated packets subjected to the predetermined processing to be shorter than the predetermined time interval, and thereafter the predetermined processing is performed. Processing for gradually increasing the time interval for outputting the accumulated packets subjected to the predetermined processing to the predetermined time interval according to the number of packets that have not been output among the accumulated packets that have been applied. And a transition control method. In the transition control method according to claim 5 ,
A process of gradually increasing the time interval at which the output device outputs the packet on which the predetermined processing has been performed from the predetermined time before the transition is started until the transition is completed from the predetermined time interval A transition control method further comprising: A packet transfer device, a first service providing device having a service providing function for receiving a packet output from the packet transfer device and performing a predetermined process on the received packet; and a packet subjected to the predetermined process Output at a predetermined time interval, a buffer device capable of storing packets, and a second service providing device, and providing the service from the first service providing device to the second service providing device A transfer control method in a packet transfer system capable of transferring functions,
A process of changing the packet output destination from the first service providing apparatus to the second service providing apparatus before the packet transfer apparatus starts the transition;
The buffer device stores the packet output from the packet transfer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
When the second service providing apparatus completes the transition, a process of performing the predetermined process on the accumulated packets;
After the transition is completed, the output device makes the time interval for outputting the accumulated packets subjected to the predetermined processing shorter than the predetermined time interval, and thereafter, the predetermined processing is performed. A process of gradually increasing a time interval for outputting the accumulated packets subjected to the predetermined processing to the predetermined time interval according to the number of packets that are not output among the accumulated packets , transition control method having. In the transition control method according to claim 7 ,
A process in which the output device gradually increases the time interval for outputting the packet on which the predetermined processing has been performed from the predetermined time before the transition is started until the transition is completed from the predetermined time interval. A transition control method further comprising: When the service providing function of receiving a packet output from the packet transfer device and performing a predetermined process on the received packet is shifted from the first service providing device to the second service providing device, A transition control device that controls the first and second service providing devices, a buffer device capable of storing packets, and an output device that outputs the packets subjected to the predetermined processing at predetermined time intervals;
A function of changing an output destination of a packet from the packet transfer apparatus from the first service providing apparatus to the second service providing apparatus before the transition is started;
A function of storing the packet output from the packet transfer device in the buffer device until the transition is completed after the output destination of the packet is changed in the packet transfer device;
A function for instructing the second service providing apparatus to perform the predetermined processing on the accumulated packets upon completion of the transition;
After the transition is completed, the output device causes the time interval for outputting the accumulated packets subjected to the predetermined processing to be shorter than the predetermined time interval, and thereafter the predetermined processing is performed. A function of gradually increasing the time interval for outputting the accumulated packets subjected to the predetermined processing to the predetermined time interval according to the number of packets that have not been output among the accumulated packets that have been applied. And a program to realize. The program according to claim 9 ,
In the transition control device,
A function of gradually increasing a time interval at which the output device outputs a packet on which the predetermined processing has been performed from a predetermined time before the transition is started until the transition is completed from the predetermined time interval. A program for further realizing this.

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