Communication statistic information collection apparatus

• US 20050276230A1
• Filed: 02/03/2005
• Published: 12/15/2005
• Est. Priority Date: 06/15/2004
• Status: Active Grant

• Current Assignee: Alaxala Networks Corporation (Fortinet Inc.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Akahane, Shinichi, Sugai, Kazuo, Ishikawa, Yuichi, Nagasaka, Mitsuru
• Granted Patent: US 7,787,442 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0894 Packet rate
• CPC Class Codes: H04L 45/60 Router architectures

Abstract

A communication statistic information collection apparatus comprises a unit for searching a flow table for a flow entry corresponding to a searching key, a unit for collecting statistics information for each of flows, a unit for generating a packet for notifying a collector apparatus of stored statistics information, a unit for updating the flow table in accordance with statistics control information shown by a statistics control entry found as a result of searching the flow table, and a unit for generating a sample packet to be transferred to the collect or apparatus at a specified sampling rate in accordance with the statistics control information shown by a specified entry found from the flow table.

Claims

1. A communication statistic information collection apparatus comprising:

a flow table composed of a plurality of flow entries each defining a flow identification condition for identifying a packet flow;

a searching unit for searching, by using a combination of a plurality of header information items extracted from a header of each of packets received from a network as a flow searching key, said flow table for a flow entry having the flow identification condition corresponding to the flow searching key, and collecting statistics information individually for each of the packet flows by using a result of searching said flow table; and

a statistics function control table including at least one statistics control entry defining, in association with the flow identification condition, statistics control information for limiting the packets for which the statistics information is to be collected, wherein

said searching unit executes searching said flow table in accordance with the flow searching key generated from the header information of each of the received packets, searching said statistics function control table when there is no flow entry corresponding to the flow searching key, and collecting, when the statistics control entry corresponding to the flow searching key is found from the statistics function control table, the statistics information of a packet flow corresponding to the flow identification condition of the statistics control entry in accordance with the statistics control information shown by the statistics control entry.

2. The communication statistic information collection apparatus according to claim 1, wherein said searching unit comprises means for changing the contents of said flow table or the statistics function control table in accordance with said statistics control information shown by the statistics control entry when the statistics control entry is found as the entry corresponding to the flow searching key.

3. The communication statistic information collection apparatus according to claim 1, further comprising:

a statistics information table composed of a plurality of statistics information entries for storing statistics information each of which is prepared in association with each of the entries in said flow table and the statistics function control table, wherein

said searching unit comprises a statistics information processing unit for performing updating the statistics information in response to packet reception in the statistics information entry corresponding to the flow entry or the statistics control entry found as a result of searching with said flow searching key.

4. The communication statistic information collection apparatus according to claim 1, wherein

said statistics function control table includes first and second statistics control entries each of which specifies, as the flow identification condition, a header information value of at least one of the plurality of header information items serving as the flow searching key,

the statistics control information of said first statistics control entry indicates to collect the statistics information for each of the packet flows identified by the flow searching key, and the statistics control information of said second statistics control entry indicates to generate of a copy of each of the received packets in the packet flow corresponding to the flow identification condition at a specified sampling rate, and

said searching unit comprises first means for adding a new flow entry having said flow searching key as the flow identification condition to said flow table when said first statistics control entry is found as the entry corresponding to the flow searching key from said statistics function control table, and second means for starting a control operation for generating the copy of the received packet corresponding to the flow identification condition at the specified sampling rate and transferring the copy packet to a specified statistics information collection apparatus when said second statistics control entry is found as the entry corresponding to the flow searching key from said statistics function control table.

5. The communication statistic information collection apparatus according to claim 1, wherein

said statistics function control table includes a first statistics control entry which specifies, as the flow identification condition, a header information value of at least one of the plurality of header information items serving as the flow searching key and includes, as a part of the statistics control information, a registration flag indicating to register a new flow entry, and

said searching unit comprises an entry management unit for adding a new entry to said flow table when said first statistics control entry is found as the statistics control entry corresponding to the flow searching key from said statistics function control table, the new flow entry having the combination of a plurality of header information items extracted from the header of the received packet as the flow identification condition.

6. The communication statistic information collection apparatus according to claim 5, wherein

said first statistics control entry includes a condition for starting statistics information collection as a part of the statistics control information and

said entry management unit compares, when said first statistics control entry is found as a result of searching said statistics function control table, the condition for starting the statistics information collection with the statistics information shown by the statistics information entry corresponding to the first statistics control entry and adds said new flow entry to said flow table when the condition for starting the statistics information collection is satisfied.

7. The communication statistic information collection apparatus according to claim 3, wherein

said statistics function control table includes a second statistics control entry which includes, as a part of the statistics control information, a condition for starting sampling to transfer a copy of the received packet generated at a specified sampling rate to a preliminarily specified statistics information collection apparatus and a sampling flag indicative of whether the sampling should be executed, and

said searching unit comprises:

a sampling determination unit for comparing, when said second statistics control entry is found as the statistics control entry corresponding to the flow searching key from said statistics function control table and the sampling flag is in an OFF state, the condition for starting said sampling with the statistics information shown by the statistics information entry corresponding to the second statistics control entry and changing said sampling flag to an ON state when the condition for starting the sampling is satisfied; and

a sampling unit for generating a control signal to generate the copy of the received packet at the specified sampling rate when the sampling flag is in the ON state.

8. The communication statistic information collection apparatus according to claim 7, wherein

said second control entry includes, as a part of the statistics control information, a condition for ending the sampling, and

said sampling determination unit compares, when the second control entry is found as a result of searching said statistics function control table and the sampling flag is in the ON state, the condition for ending said sampling with the statistics information shown by the statistics information entry corresponding to the second control entry and returns said sampling flag to the OFF state when the condition for ending the sampling is satisfied.

9. The communication statistic information collection apparatus according to claim 7, wherein the condition for starting said sampling is specified by a bandwidth value of the packet flow and the statistics information entry corresponding to said second statistics control entry includes a bandwidth as one of the statistics information items.

10. A communication statistic information collection apparatus comprising:

a flow table composed of a plurality of flow entries each defining a flow identification condition for identifying a packet flows; and

a searching unit for searching, by using a combination of a plurality of header information items extracted from a header of each of packets received from a network as a flow searching key, said flow table for a flow entry having the flow identification condition corresponding to the flow searching key, and collecting statistics information individually for each of the packet flows by using a result of searching said flow table, wherein

said flow table includes at least one statistics control entry defining, in association with the flow identification condition, statistics control information for limiting the packets for which the statistics information is to be collected, and

said searching unit executes, when said statistics control entry is found as the entry corresponding to the flow searching key generated from the header information of each of the received packets as a result of searching said flow table, collecting the statistics information of a packet flow corresponding to the flow identification condition of the statistics control entry in accordance with the statistics control information shown by the statistics control entry.

11. The communication statistic information collection apparatus according to claim 10, wherein said searching unit comprises means for changing the contents of said flow table or the statistics function control table in accordance with said statistics control information shown by the statistics control entry, when the statistics control entry is found as the entry corresponding to the flow searching key.

12. The communication statistic information collection apparatus according to claim 10, further comprising:

a statistics information table composed of a plurality of statistics information entries for storing statistics information, each of which is prepared in association with each of the entries in said flow table, wherein

said searching unit comprises a statistics information processing unit for performing, in response to packet reception, updating the statistics information in the statistics information entry corresponding to the flow entry found as a result of searching said flow table.

13. The communication statistic information collection apparatus according to claim 10, wherein

said flow table includes a first statistics control entry which specifies, as the flow identification condition, a header information value of at least one of the plurality of header information items serving as the searching key and includes, as a part of the statistics control information, a registration flag indicating to register a new flow entry to said flow table, and

said searching unit adds a new entry to said flow table when said first statistics control entry is found as a result of searching said flow table, the new flow entry having the combination of a plurality of header information items extracted from the header of the received packets as the flow identification condition.

14. The communication statistic information collection apparatus according to claim 12, wherein

said flow table includes a second statistics control entry including, as a part of the statistics control information, a condition for starting sampling in which a copy of the received packets generated at a specified sampling rate is transferred to a preliminarily specified statistics information collection apparatus and a sampling flag indicative of whether the sampling should be executed, and

said searching unit comprises:

a sampling determination unit for determining, when said second statistics control entry is found as a result of searching said flow table and the sampling flag is in an OFF state, whether the sampling should be started based on the condition for starting said sampling and the statistics information shown by the statistics information entry corresponding to the second statistics control entry and changes said sampling flag to an ON state at a time at which the condition for starting the sampling is satisfied; and

a sampling unit for generating a control signal to generate the copy of the received packet at the specified sampling rate when the sampling flag is in the ON state.

15. The communication statistic information collection apparatus according to claim 14, wherein

said second control entry includes, as a part of the statistics control information, a condition for ending the sampling, and

said sampling determination unit determines, when the second control entry is found as a result of searching said flow table and the sampling flag is in the ON state, whether the sampling should be ended based on the condition for ending said sampling and the statistics information shown by the statistics information entry corresponding to the statistics control entry and returns said sampling flag to the OFF state when the condition for ending the sampling is satisfied.

16. The communication statistic information collection apparatus according to claim 13, wherein the condition for starting said sampling is specified by a bandwidth value of the packet flow and the statistics information entry corresponding to said second statistics control entry includes a bandwidth as one of the statistics information items.

17. A communication statistic information collection apparatus connected to a network, said communication statistic information collection apparatus comprising:

a flow table composed of a plurality of flow entries each defining statistics control information in association with flow identification condition for identifying a packet flow;

a statistics information table composed of a plurality of statistics information entries for storing statistics information, each of which is prepared in association with each of the entries in said flow table;

a flow table searching unit for searching, by using a combination of a plurality of header information items extracted from a header of each of packets received from said network as a flow searching key, said flow table for a flow entry having the flow identification condition corresponding to the flow searching key;

a statistics information processing unit for collecting statistics information individually for each of the packet flows in one of the statistics information entries which is corresponding to the flow entry found by said flow table searching unit as a result of searching;

a statistics information notification packet generation unit for generating a packet for notifying a preliminarily specified statistic information collection apparatus of the statistics information stored in said statistics information table; and

a copy generation unit for generating a copy of the received packet to be transferred to the preliminarily specified statistic information collection apparatus at a specified sampling rate in accordance with the statistics control information shown by the specified flow entry found by said flow table searching unit as a result of searching.

18. The communication statistic information collection apparatus according to claim 17, wherein

said flow table includes at least one statistics control entry defining the statistic control information for limiting the packets for which the statistics information is to be collected, in association with the flow identification condition specifying a header information value of at least one of the plurality of header information items serving as the flow searching key,

the communication statistic information collection apparatus further comprising:

an entry management unit for adding, when said statistics control entry is found as the entry corresponding to the flow searching key as a result of searching performed by said flow table searching unit, a new flow entry having the contents of said flow searching key as the flow identification condition to said flow table in accordance with the statistics control information shown by the statistics control entry.

19. The communication statistic information collection apparatus according to claim 18, wherein said entry management unit monitors a state change in said statistics information table, detects one of the statistics information entries in which the statistics information has remained unchanged for a period longer than a specified time, reads out the statistics information shown by the statistics information entry and the flow identification condition corresponding to the statistics information entry from said statistics information table and said flow table, respectively, and supplies the statistics information and the read flow identification condition to said statistics information notification packet generation unit.

20. The communication statistic information collection apparatus according to claim 18, wherein said entry management unit selects a flow entry to be deleted from said flow table as required when adding the new flow entry to said flow table, reads out the flow identification condition shown by the selected flow entry and the statistics information shown by the statistics information entry corresponding to the selected flow entry from said flow table and said statistics information table, respectively, and supplies the flow identification condition and the statistics information to said statistics information notification packet generation unit.