1. A non-transitory computer-readable storage medium storing therein a packet processing program for causing a computer to execute a process comprising:
specifying, according to acquisition of an IP packet, on the basis of information for specifying a communication session included in a header of the acquired IP packet, a communication session in which the acquired IP packet is transmitted and received;
referring to management information corresponding to the specified communication session, the management information, corresponding to IP packet identifiers included in headers of IP packets and corresponding to a communication session, being stored in a storage; and
discarding the acquired IP packet when the management information corresponding to an IP packet identifier of the acquired IP packet is present in the storage and, when the management information corresponding to the IP packet identifier of the acquired IP packet is absent in the storage, storing the management information corresponding to the IP packet identifier of the acquired IP packet in the storage and outputting the acquired IP packet.
2. The non-transitory computer-readable storage medium according to claim 1, wherein
the storage includes a plurality of storage regions where the management information corresponding to each of the IP packet identifiers is stored respectively,
the specifying includes determining that the management information corresponding to the IP packet identifier of the acquired IP packet is present when first information is stored in the storage regions corresponding to the IP packet identifier of the acquired IP packet, and determining that the management information corresponding to the IP packet identifier of the acquired IP packet is absent when second information is stored in the storage regions corresponding to the IP packet identifier of the acquired IP packet.
3. The non-transitory computer-readable storage medium according to claim 2, wherein information of 1 bit is able to be stored in each of the storage regions.
4. The non-transitory computer-readable storage medium according to claim 2, wherein
the IP packet identifiers are allocated in order of transmission of the IP packets, and
the packet processing program further causes the computer to execute a process comprising:
first storing, when the IP packet identifier of the acquired IP packet cycles, the second information in the management information corresponding a communication session corresponding to the cycling IP packet identifier and corresponding to a predetermined number of IP packet identifiers from a head of management information in the storage; and
second storing, when the IP packet identifier of the acquired IP packet is an IP packet identifier corresponding to the management information in which the first information may be stored, the second information in the management information corresponding to the predetermined number of IP packet identifiers continuous to the IP packet identifiers corresponding to the management information in which the second information has been stored in the first storing.
5. The non-transitory computer-readable storage medium according to claim 2, wherein the packet processing program further causes the computer to execute a process comprising third storing the second information in the management information of which a storage period elapses after the first information is stored.
6. The non-transitory computer-readable storage medium according to claim 5, wherein, the third storing includes:
storing the IP packet identifiers of the IP packet for which the first information is stored in each of continuous totaling periods, and
storing the second information in the management information corresponding to the totaling period in which a period from storing the first information exceeds the storage period.
7. The non-transitory computer-readable storage medium according to claim 6, wherein, the third storing includes reducing the totaling period when an acquisition frequency of the IP packet is greater than a predetermined threshold, and extending the totaling period when the acquisition frequency of the IP packet is less than the predetermined threshold.
8. The non-transitory computer-readable storage medium according to claim 1, wherein the referring includes, when the discarding of an IP packet included first communication session does not occur for a first predetermined period, stopping the referring to the management information corresponding to the first communication session.
9. The non-transitory computer-readable storage medium according to claim 8, wherein the referring includes resuming the referring to the management information corresponding to the first communication session when a second predetermined period elapses after stopping the referring to the management information corresponding to the first communication session.
10. The non-transitory computer-readable storage medium according to claim 8, wherein the referring includes, when the discarding of the IP packet included the first communication session does not occur for the first predetermined period, erasing information to refer the management information corresponding to the first communication session.
11. A redundant packet detecting apparatus comprising:
a storage configured to store management information corresponding to IP packet identifiers included in headers of IP packets; and
a processor configured to specify, according to acquisition of an IP packet, on the basis of information for specifying a communication session included in a header of the acquired IP packet, a communication session in which the acquired IP packet is transmitted and received, refer to management information corresponding to the specified communication session, the management information, corresponding to IP packet identifiers included in headers of IP packets and corresponding to a communication session, being stored in a storage, and discard the acquired IP packet when the management information corresponding to an IP packet identifier of the acquired IP packet is present in the storage and, when the management information corresponding to the IP packet identifier of the acquired IP packet is absent in the storage, store the management information corresponding to the IP packet identifier of the acquired IP packet in the storing unit and output the acquired IP packet.
12. A packet processing method comprising:
specifying, by a processor, according to acquisition of an IP packet, on the basis of information for specifying a communication session included in a header of the acquired IP packet, a communication session in which the acquired IP packet is transmitted and received;
referring, by a processor, to management information corresponding to the specified communication session, the management information, corresponding to IP packet identifiers included in headers of IP packets and corresponding to a communication session, being stored in a storage; and
discarding, by a processor, the acquired IP packet when the management information corresponding to an IP packet identifier of the acquired IP packet is present in the storage and, when the management information corresponding to the IP packet identifier of the acquired IP packet is absent in the storage, storing, by a processor, the management information corresponding to the IP packet identifier of the acquired IP packet in the storage and outputting, by a processor, the acquired IP packet.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A magneto-optical recording medium processing apparatus for performing at the least one of reproduction, recording and erasing on a magneto-optical recording medium, comprising:
a carriage for moving an optical head, which irradiates an optical beam onto said magneto-optical recording medium, in the target position of said magneto-optical recording medium;
a drive current controller for supplying drive current to said carriage;
a bias magnetic field generator for applying a bias magnetic field to said magneto-optical recording medium; and
a bias current controller for supplying a bias current to said bias magnetic field generator,
wherein said bias current controller controls a bias current value in accordance with a drive current supply.
2. The magneto-optical recording medium processing apparatus according to claim 1, wherein said bias current controller controls to limit a bias current value in relation to a specified value while drive current is being supplied.
3. The magneto-optical recording medium processing apparatus according to claim 2, wherein said bias current controller sets said bias current value to a predetermined value, which is smaller than said specified value.
4. The magneto-optical recording medium processing apparatus according to claim 2, wherein said bias current controller sets said bias current value such that the sum total of a drive current value and a bias current value do not exceed an allowable current value.
5. The magneto-optical recording medium processing apparatus according to claim 2, wherein said bias current controller sets different bias current values for at the least two time periods of the time period during which drive current is being supplied for constant velocity movement of said carriage, the time period during which drive current is being supplied for deceleration movement of said carriage, and the time period during which drive current is being supplied for the acceleration movement of said carriage.
6. The magneto-optical recording medium processing apparatus according to claim 5, wherein said bias current controller sets said bias current value to a predetermined value, which is smaller than said specified value, for at the least one time period of said time periods.
7. The magneto-optical recording medium processing apparatus according to claim 5, wherein said bias current controller sets said bias current value, such that the total of a drive current value and a bias current value do not exceed an allowable current value, for at the least one time period of said time periods.
8. The magneto-optical recording medium processing apparatus according to claim 2, wherein said bias current controller supplies a bias current of said specified value, regardless of the supply of drive current, when either the movement time or movement distance of said carriage is shorter than a predetermined value.
9. The magneto-optical recording medium processing apparatus according to claim 2, wherein said specified value is a bias current value required subsequent to the movement of said carriage, which is moved by a drive current supply.