Packet forwarding apparatus, method and program

A packet processing method performed by a packet transfer device configured to transmit received packets to an external device, the packet transfer device including a packet classification unit configured to classify the received packets into classifications as classified packets such that at least a series of packets related to an identical communication flow are classified into an identical classification, queues configured to hold the classified packets, each queue holding packets in one of the classifications, priorities being set to the queues, and a dequeue processing unit configured to extract packets from the queues under a predetermined rule based on the priorities set to the queues, the method comprising:

• performing, by a queue priority control unit, a control, upon detecting that a reception amount of packets related to a communication flow temporarily or intermittently increases from a reception amount under a normal condition, such that a priority class of one of the queues holding the packets related to the communication flow is raised to a high priority class from a lower priority class under the normal condition, during a period while the reception amount of the packets related to the communication flow temporarily or intermittently increases;
• and
• performing, by the queue priority control unit, a control, upon detecting that the reception amount of the packets is returned to the reception amount under the normal condition, such that the high priority class of the one of the queues holding the packets is temporarily lowered and then set to the lower priority class under the normal condition;
• wherein the detecting, by the queue priority control unit, that the reception amount of the packets related to the communication flow temporarily or intermittently increases from the reception amount under the normal condition is based on information stored in a payload of each received packet and stored in a header on an application level.

A non-transitory computer readable medium comprising a packet processing program that causes a computer to operate as respective functional units of a packet transfer device comprising:

• performing, by a queue priority control unit, a control, upon detecting that a reception amount of packets related to a communication flow temporarily or intermittently increases from a reception amount under a normal condition, such that a priority class of a queue holding the packets related to the communication flow is raised to a high priority class from a lower priority class under the normal condition, during a period while the reception amount of the packets related to the communication flow temporarily or intermittently increases;
• and
• performing, by the queue priority control unit, a control, upon detecting that the reception amount of the packets is returned to the reception amount under the normal condition, such that the high priority class of the one of the queues holding the packets is temporarily lowered and then set to the lower priority class under the normal condition;
• wherein the detecting, by the queue priority control unit, that the reception amount of the packets related to the communication flow temporarily or intermittently increases from the reception amount under the normal condition is based on information stored in a payload of each received packet and stored in a header on an application level.