METHOD FOR ROUTING INFORMATION OVER A NETWORK EMPLOYING CENTRALIZED CONTROL

• US 20100208622A1
• Filed: 04/30/2010
• Published: 08/19/2010
• Est. Priority Date: 12/30/2000
• Status: Active Grant

• Current Assignee: Ali N. Saleh, Vahid Parsi, Zadikian H. Michael, Zareh Baghdasarian
• Original Assignee: Ali N. Saleh, Vahid Parsi, Zadikian H. Michael, Zareh Baghdasarian
• Inventors: Baghdasarian, Zareh, Parsi, Vahid, Zadikian, H. Michael, Saleh, Ali N.
• Granted Patent: US 8,081,582 B2
• Time in Patent Office: Days
• US Class Current: 370/255
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 41/0803 Configuration setting
• CPC Class Codes: H04L 41/0866 Checking the configuration
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 41/122 of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV]

Abstract

A method and apparatus for centralized control of a network is described. The network includes a number of nodes. The method includes creating a database and storing the database on a master node of the network. The database contains topology information regarding a topology of the network. Each of the nodes is coupled to at least one other of the nodes, with the master node being one of the nodes.

Claims

1. A method for determining a topology of a network, wherein said network comprises a plurality of nodes, comprising:

receiving a message at a node, wherein

said message is sent by a master node, and

each of said nodes is communicatively coupled to another of said nodes by at least one of a plurality of optical links;

forwarding said message to a neighbor node, wherein said neighbor node is a one of said nodes that is a neighbor of said node; and

sending a positive reply to said master node.

2. The method of claim 1, wherein said node and said master node are ones of said nodes.

3. The method of claim 1, wherein said message is an IAM_MASTER message.

4. The method of claim 1, further comprising:

determining if said message can be forwarded.

5. The method of claim 4, wherein said determining if said message can be forwarded comprises:

updating a hop count of said message;

comparing said hop count to a maximum hop count; and

forwarding said message if said comparison indicates that said message can be forwarded.

6. The method of claim 1, further comprising:

comparing a version number of an executable image stored at said node and a version number in said message corresponding to said executable image.

7. The method of claim 6, further comprising:

making a list of executable images stored at said node that require updating.

8. The method of claim 6, further comprising:

if said comparison indicates that said executable image stored at said node requires updating,

requesting said master node forward a replacement executable, wherein said replacement executable is a copy of an executable stored at said master node corresponding to said executable image stored at said node, and

replacing said executable image stored at said node with said replacement executable.

9. The method of claim 1, further comprising:

determining if a master node identified in said message is a master node identified in another message received by said node;

analyzing a hop count and a source node identified in said message, if said master node identified in said message is said master node identified in said another message, and

analyzing a node identifier of said master node identified in said message, otherwise.

10. The method of claim 9, wherein said analyzing said hop count and said source node identified in said message comprises:

performing a first comparison between said hop count identified in said message and a hop count identified in said another message;

performing a second comparison between said source node identified in said message and a source node identified in said another message; and

dropping said message, if either of said first and said second comparisons fail, and

determining if said message can be forwarded, otherwise.

11. The method of claim 10, wherein said determining if said message can be forwarded comprises:

updating a hop count of said message;

comparing said hop count to a maximum hop count; and

forwarding said message if said comparison indicates that said message can be forwarded.

12. A method for maintaining topology information regarding a topology of a network, wherein said network comprises a plurality of nodes, comprising:

sending a message from a master node to a backup node, wherein

each of said nodes is communicatively coupled to another of said nodes by at least one of a plurality of optical links;

receiving a reply from said backup node at said master node;

comparing information in said reply regarding a backup database maintained on said backup node with information regarding an authoritative database maintained on said master node; and

sending a copy of said authoritative database from said master node to said backup node, if said comparison indicates that said backup database should be updated.

13. The method of claim 12, wherein said backup node and said master node are ones of said nodes.

14. The method of claim 12, further comprising:

receiving said copy of said authoritative database at said backup node; and

replacing said backup database with said copy of said authoritative database.

15. The method of claim 13, further comprising:

forwarding said copy of said backup database from said backup node to a standby node.

16. The method of claim 12, further comprising:

sending a copy of a dynamic database from said master node to said backup node.

17. The method of claim 16, further comprising:

forwarding said copy of said dynamic database from said backup node to a standby node.

18. The method of claim 12, further comprising:

forwarding said copy of said backup database from said backup node to a standby node;

storing said copy of said backup database as a standby database.

19. The method of claim 18, further comprising:

maintaining synchronization between said authoritative database, said backup database and said standby database.