Method for routing information over a network employing centralized control

• US 8,081,582 B2
• Filed: 04/30/2010
• Issued: 12/20/2011
• Est. Priority Date: 12/30/2000
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Saleh, Ali N., Zadikian, H. Michael, Baghdasarian, Zareh, Parsi, Vahid
• Primary Examiner(s): Jung, Min
• Application Number:
  US12/771,814
• Publication Number:
  US 20100208622A1
• Time in Patent Office: 599 Days
• Field of Search: None
• US Class Current: 370/254
• 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 comprising:

determining a topology of a network, wherein

said network comprises a plurality of nodes,

said nodes comprise a node, a master node, and a backup node,

said master node stores an authoritative topology database,

said backup node stores a backup topology database,

said authoritative topology database and said backup topology database are configured to represent said topology, and

said determining comprises

receiving a message at said node, wherein

said message is sent by said master node,

said message comprises information regarding said authoritative topology database, 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 positive reply comprises

a node identifier of said node,

a node type of said node, and

a system inventory for said node, and

said system inventory comprises a list of resources maintained by said node.

3. The method of claim 1, wherein

said message is an IAM_MASTER message,

a plurality of executable images are stored at said master node, and said IAM_MASTER message comprises at least one of

an identifier, wherein

said identifier identifies said master node as a one of said nodes storing said executable images,

a version number of each executable image of said executable images, or

a database identifier, wherein

said information regarding said authoritative topology database comprises said database identifier, and

said database identifier identifies said authoritative topology database.

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 image, wherein

said replacement executable image is a copy of an executable image stored at said master node, and

said replacement executable image corresponds 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 13, further comprising:

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

15. 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.

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.

20. A network device comprising:

a processor;

a computer-readable medium coupled to said processor; and

computer code, wherein

said computer code is encoded in said computer-readable medium, and

said computer code is configured to cause said processor to determine a topology of a network, wherein

said network device is a node of a plurality of nodes,

said network comprises said nodes,

said nodes further comprise a master node and a backup node,

said master node stores an authoritative topology database,

said backup node stores a backup topology database,

said authoritative topology database and said backup topology database are configured to represent said topology, and

said computer code is configured to cause said processor to determine comprises computer code configured to cause said processor to

receive a message at said node, wherein

 

said message is sent by said master node,

 

said message comprises information regarding said authoritative topology database, and

 

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

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

send a positive reply to said master node.