COMMUNICATION CONTROL SYSTEM AND COMMUNICATION CONTROL METHOD

• US 20130046882A1
• Filed: 01/04/2011
• Published: 02/21/2013
• Est. Priority Date: 01/06/2010
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hidaka, Youichi, Takashima, Masanori, Izawa, Tetsu
• Granted Patent: US 9,432,283 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 45/42 Centralised routing
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/54 Organization of routing tables

Abstract

In the case of a system where a communication device is remote-controlled from a control server, depending on timing when an entry is written into a forwarding table of the communication device from the control server, there is a possibility that a loop and discard of the traffic occur. Therefore, for registration, rewriting and deletion of the entry of the forwarding table which are performed on the communication device 102 by the control server 101; the communication device 102 verifies contents of control instructions from the control server 101; the communication device 102 holds the result of this verification; the control server 101 acquires the result of the verification; the control server 101 judges whether or not a series of controls can be executed based on the results of the verification from the plurality of communication devices 102; and then the control server 101 invokes the execution at the plurality of communication devices 102.

Claims

1. A communication control system comprising:

a plurality of communication devices, each of said plurality of communication devices configured to perform matching of a received traffic and an entry registered in a forwarding table, and, when information contained in said traffic and information contained in said entry match each other, forward said traffic to a route defined in said entry; and

a control server configured to register an entry in a forwarding table included in said each of said plurality of communication devices, and determine rout information for said each communication device,

wherein said each communication device verifies, for a sequence of control instructions from said control server, contents of said control instructions from said control server and holds a verification result,

wherein said control sever acquires said verification result from said each communication device, determines whether a sequence of control can be executed by said each communication device based on said verification result from said each communication device, and, if said sequence of control can be executed, invokes said each communication device to execute said sequence of control.

2. The communication control system according to claim 1, wherein, for said sequence of control instructions from said control server, said each communication device once executes said sequence of control,

wherein, when said control server judges that said contents of said control instructions from said control server is abnormal, invokes execution of a rollback of said execution result to said each communication device.

3. The communication control system according to claim 1, wherein, when said each communication device receives a control command for new entry addition instructions to said forwarding table from said control server,

with reference to said forwarding table, said each communication device checks whether or not there is any empty entry in said forwarding table,

if there is any empty entry, said each communication device checks whether or not there is any entry having inclusion relationship or partial inclusion relationship in said forwarding table, and

if there is any entry having said inclusion relationship or said partial inclusion relationship, said each communication device checks a priority of said entry and performs said control command from said control server.

4. The communication control system according to claim 3, wherein if there is no empty entry or if said each communication device checks whether or not there is any entry having inclusion relationship or partial inclusion relationship, said each communication device sets a sequence of control at standby state to wait for a instructions from said control server, and receives a new control command from said control server,

if said new control command is processing execution, said each communication device adds an entry to said forwarding table based on said control command from said control server, and

if said new control command is rollback instructions, said each communication device does not add an entry to said forwarding table and performs processing in accordance with a rollback function based on said control command from said control server.

5. A communication device in a communication control system, wherein said communication control system includes:

a plurality of communication devices; and

a control server configured to register an entry in a forwarding table included in each of said plurality of communication devices, and determine rout information for said each of said plurality of communication devices,

wherein said communication device is any of said plurality of communication devices,

said communication device comprising;

a data forwarding section configured to perform matching of a received traffic and an entry registered in a forwarding table, and, when information contained in said traffic and information contained in said entry match each other, forward said traffic to a route defined in said entry; and

a transaction management section configured to verify, for a sequence of control instructions from said control server, contents of said control instructions from said control server and hold a verification result,

wherein said control sever acquires said verification result from said each communication device, determines whether a sequence of control can be executed by said each communication device based on said verification result from said each communication device, and, if said sequence of control can be executed, invokes said each communication device to execute said sequence of control.

11. The communication device according to claim 5, further comprising:

a control server interface section configured to, for said sequence of control instructions from said control server, once execute said sequence of control,

wherein, when said control server judges that said contents of said control instructions from said control server is abnormal, invokes execution of a rollback of said execution result to said each communication device.

12. The communication device according to claim 5, further comprising:

a table search section configured to, when said communication device receives a control command for new entry addition instructions to said forwarding table from said control server, with reference to said forwarding table, check whether or not there is any empty entry in said forwarding table,

wherein if there is any empty entry, said table search section checks whether or not there is any entry having inclusion relationship or partial inclusion relationship in said forwarding table, and

if there is any entry having said inclusion relationship or said partial inclusion relationship, said table search section checks a priority of said entry and performs said control command from said control server.

13. The communication device according to claim 12, wherein if there is no empty entry or if said table search section checks whether or not there is any entry having inclusion relationship or partial inclusion relationship, said table search section sets a sequence of control at standby state to wait for a instructions from said control server,

said communication device further comprising:

a control server interface section configured to receive a new control command from said control server,

wherein if said new control command is processing execution, said control server interface section adds an entry to said forwarding table based on said control command from said control server, and

if said new control command is rollback instructions, said control server interface section does not add an entry to said forwarding table and performs processing in accordance with a rollback function based on said control command from said control server.

6. A communication control method comprising:

a control server registering an entry in a forwarding table included in each of a plurality of communication devices and determining rout information for each of said plurality of communication devices;

said each of said plurality of communication devices performing matching of a received traffic and an entry registered in a forwarding table, and when information contained in said traffic and information contained in said entry match each other, forwarding said traffic to a route defined in said entry;

said each communication device, for a sequence of control instructions from said control server, verifying contents of said control instructions from said control server and holding a verification result; and

said control sever acquiring said verification result from said each communication device, determining whether a sequence of control can be executed by said each communication device based on said verification result from the each communication device, and, if said sequence of control can be executed, invoking said each communication device to execute said sequence of control.

7. The communication control method according to claim 6, further comprising:

said each communication device, for said sequence of control instructions from said control server, once executing said sequence of control; and

said control server invoking execution of a rollback of said execution result to said each communication device, when said control server judges that said contents of said control instructions from said control server is abnormal.

8. The communication control method according to claim 6, further comprising:

said each communication device, when said each communication device receives a control command for new entry addition instructions to said forwarding table from said control server, checking whether or not there is any empty entry in said forwarding table, with reference to said forwarding table;

said each communication device, if there is any empty entry, checking whether or not there is any entry having inclusion relationship or partial inclusion relationship in said forwarding table;

said each communication device, if there is any entry having said inclusion relationship or said partial inclusion relationship, checking a priority of said entry; and

said each communication device performing said control command from said control server.

9. The communication control method according to claim 8, further comprising:

said each communication device, if there is no empty entry or if said each communication device checks whether or not there is any entry having inclusion relationship or partial inclusion relationship, setting a sequence of control at standby state to wait for a instructions from said control server;

said each communication device receiving a new control command from said control server;

said each communication device, if said new control command is processing execution, adding an entry to said forwarding table based on said control command from said control server; and

said each communication device, if said new control command is rollback instructions, not adding an entry to said forwarding table and performing processing in accordance with a rollback function based on said control command from said control server.

10. A recording medium which records a computer program for executing a part of a communication control method by a communication control system composed of a plurality of communication devices and a control server registering an entry in a forwarding table included in each of said plurality of communication devices and determining rout information for each of said plurality of communication devices,

said computer program composing code operable to control a computer as each of said plurality of communication devices, the code comprising:

performing matching of a received traffic and an entry registered in a forwarding table, and when information contained in said traffic and information contained in said entry match each other, forwarding said traffic to a route defined in said entry; and

for a sequence of control instructions from said control server, verifying contents of said control instructions from said control server and holding a verification result,

wherein said control sever acquires said verification result from said each communication device, determines whether a sequence of control can be executed by said each communication device based on said verification result from the each communication device, and, if said sequence of control can be executed, invokes said each communication device to execute said sequence of control.

16. The recording medium according to claim 10, further comprising:

for said sequence of control instructions from said control server, once executing said sequence of control,

wherein said control server invokes execution of a rollback of said execution result to said each communication device, when said control server judges that said contents of said control instructions from said control server is abnormal.

17. The recording medium according to claim 10, further comprising:

when receiving a control command for new entry addition instructions to said forwarding table from said control server, checking whether or not there is any empty entry in said forwarding table, with reference to said forwarding table;

if there is any empty entry, checking whether or not there is any entry having inclusion relationship or partial inclusion relationship in said forwarding table;

if there is any entry having said inclusion relationship or said partial inclusion relationship, checking a priority of said entry; and

performing said control command from said control server.

18. The recording medium according to claim 17, further comprising:

if there is no empty entry or if said each communication device checks whether or not there is any entry having inclusion relationship or partial inclusion relationship, setting a sequence of control at standby state to wait for a instructions from said control server;

receiving a new control command from said control server;

if said new control command is processing execution, adding an entry to said forwarding table based on said control command from said control server; and

if said new control command is rollback instructions, not adding an entry to said forwarding table and performing processing in accordance with a rollback function based on said control command from said control server.

14. A control server in a communication control system, wherein said communication control system includes:

a plurality of communication devices, each of said plurality of communication devices configured to perform matching of a received traffic and an entry registered in a forwarding table, and, when information contained in said traffic and information contained in said entry match each other, forward said traffic to a route defined in said entry; and

said control server configured to register an entry in a forwarding table included in said each of said plurality of communication devices, and determine rout information for said each communication device,

said control server comprising;

a means for outputting a sequence of control instructions to said each communication device;

a means for acquiring a verification result from said each communication device, said each communication device verifying, for said sequence of control instructions from said control server, contents of said control instructions from said control server and holding said verification result;

a means for determining whether a sequence of control can be executed by said each communication device based on said verification result from said each communication device; and

a means for, if said sequence of control can be executed, invoking said each communication device to execute said sequence of control.

15. The control server according to claim 14, wherein, for said sequence of control instructions from said control server, said each communication device once executes said sequence of control,

said control server further comprising:

a means for judging whether or not said contents of said control instructions from said control server is abnormal, and

a means for, when said contents of said control instructions from said control server is abnormal, invoking execution of a rollback of said execution result to said each communication device.

19. A recording medium which records a computer program for executing a part of a communication control method by a communication control system composed of a plurality of communication devices, each of said plurality of communication devi es performing matching of a received traffic and an entry registered in a forwarding table, and when information contained in said traffic and information contained in said entry match each other, a forwarding table included in said each of said plurality of communication devices and a forwarding table included in said each of said plurality of communication devices and determining rout information for each of said plurality of communication devices,

said computer program comprising code operable to control a computer as said control server, the code composing:

outputting a sequence of control instructions to said each communication device;

acquiring a verification result from said each communication device, said each communication device verifying, for said sequence of control instructions from said control server, contents of said control instructions from said control server and holding said verification result;

determining whether a sequence of control can be executed by said each communication device based on said verification result from the each communication device; and

if said sequence of control can be executed, invoking said each communication device to execute said sequence of control.

20. The recording medium according to claim 19, wherein, for said sequence of control instructions from said control server, said each communication device once executing said sequence of control,

said recording medium further comprising:

judging whether or not said contents of said control instructions from said control server is abnormal, and

when said contents of said control instructions from said control server is abnormal, invoking execution of a rollback of said execution result to said each communication device.