Protocol for the determination of network topology

• US 20010033548A1
• Filed: 12/29/2000
• Published: 10/25/2001
• Est. Priority Date: 01/15/1999
• Status: Active Grant

• Current Assignee: Ali Najib Saleh, Haig Michael Zadikian, Vahid Parsi, Zareh Baghdasarian
• Original Assignee: Ali Najib Saleh, Haig Michael Zadikian, Vahid Parsi, Zareh Baghdasarian
• Inventors: Parsi, Vahid, Baghdasarian, Zareh, Zadikian, Haig Michael, Saleh, Ali Najib
• Granted Patent: US 7,729,337 B2
• Time in Patent Office: Days
• US Class Current: 370/218
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/32 Flooding denial of service attacks H04L63/1458
• CPC Class Codes: H04L 45/62 Wavelength based optical switching H04Q11/0062
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0098 Mesh

Abstract

A method of operating an optical network is described. The network includes a number of nodes connected by a number of links. A method according to the present invention provisions a virtual path between a first and a second one of the plurality of nodes by: identifying the first and the second nodes, discovering a physical path from the first node to the second node, and establishing the virtual path. The method discovers a physical path from the first node to the second node by automatically identifying nodes forming the physical path. The method establishes the virtual path by configuring a set of connections between the nodes forming the physical path.

Claims

1. A method of operating a network, the network comprising:

a plurality of nodes connected by a plurality of optical links, comprising provisioning a virtual path between a first node and a second node of said plurality of nodes, wherein provisioning comprises;

identifying said first node and said second node of said plurality of nodes,

discovering a physical path from said node to said second node by automatically identifying any intermediary nodes of said physical path, and

establishing said virtual path by configuring a set of connections between said nodes of said physical path.

2. The method of

claim 1

, further comprising:

testing said virtual path by testing each one of said plurality of nodes and said plurality of links in said physical path as a single circuit.

3. The method of

claim 1

, further comprising:

allocating intermediary links between said first, said second and said intermediary nodes.

4. The method of

claim 3

, further comprising:

terminating said virtual path by automatically deallocating said intermediary links.

5. The method of

claim 4

, wherein said intermediary links are available for re-use upon deallocation.

6. The method of

claim 3

, further comprising:

terminating said virtual path by sending a termination message from one of said first and said second nodes to the other of said first and said second nodes, wherein said termination message is sent along said physical path and each one of said intermediary links is deallocated by a respective one of said nodes as said termination message is sent to each of said nodes.

7. The method of

claim 6

, wherein said intermediary links are available for re-use upon deallocation.

8. The method of

claim 6

, wherein said intermediary links are deallocated substantially simultaneously upon reception of a broadcasted termination message.

9. The method of

claim 1

, further comprising:

restoring said virtual path in response to a failure along said physical path by;

discovering an alternate physical path from said first node to said second node by automatically identifying intermediary nodes of said alternate physical path, and

re-establishing said virtual path by configuring a set of connections between said nodes of said alternate physical path.

10. The method of

claim 9

, wherein at least one of said intermediary nodes of said physical path is also one of said intermediary nodes forming said alternate physical path.

11. The method of

claim 1

, further comprising:

sending messages to maintain knowledge of a topology of the network and to determine if neighboring nodes have failed.

12. The method of

claim 11

, wherein each one of said plurality of nodes obtains information on neighboring ones of said plurality of nodes such that each one of said plurality of nodes is able to maintain a database representing a topology of the network.

13. The method of

claim 12

, wherein use of said database in said discovering said physical path allows said discovering said physical path to proceed more quickly.

14. A method of restoring a virtual path in an optical network, said virtual path being provisioned on a physical path between a first and a second node of the optical network, the optical network comprising a plurality of nodes connected by a plurality of links, the method comprising:

discovering an alternate physical path from said first node to said second node by automatically identifying nodes of said alternate physical path, and

re-establishing said virtual path by configuring a set of connections between said nodes of said alternate physical path.

15. The method of

claim 14

, wherein said discovering and said re-establishing are performed in less than one second.

16. The method of

claim 14

, wherein said discovering and said re-establishing are performed in less than 200 ms.

17. The method of

claim 14

, wherein said discovering and said re-establishing are performed in less than 50 ms.

18. The method of

claim 14

, wherein said virtual path is restored in response to a failure along said physical path, the method further comprising:

detecting said failure, wherein said detecting, said discovering, and said re-establishing are performed in less than one second.

19. The method of

claim 14

, wherein said virtual path is restored in response to a failure along said physical path, the method further comprising:

detecting said failure, wherein said detecting, said discovering, and said re-establishing are performed in less than 200 ms.

20. The method of

claim 14

, wherein said virtual path is restored in response to a failure along said physical path, the method further comprising:

detecting said failure, wherein said detecting, said discovering, and said re-establishing are performed in less than 50 ms.

21. The method of

claim 14

, wherein each one of said plurality of nodes obtains information on neighboring ones of said plurality of nodes such that each one of said plurality of nodes is able to maintain a database representing a topology of the optical network and use of said database in said discovering said alternate physical path allows said discovering to otherwise proceed more quickly.

22. The method of

claim 14

, wherein at least one of said nodes of said physical path is also one of said nodes of said alternate physical path.

27. The computer program product of

claim 21

, further comprising a graphical user interface for displaying a topology of said optical network.

31. The computer program product of

claim 21

, wherein the computer readable media includes any of magnetic storage media, including disk and tape storage media;

optical storage media, including compact disk memory and digital video disk storage media;

nonvolatile memory storage memory;

volatile storage media; and

data transmission media including computer network, point-to-point telecommunication, and carrier wave transmission media.

23. A method of operating an optical network, the optical network comprising a plurality of nodes connected by a plurality of links, wherein each one of said plurality of nodes obtains information on neighboring ones of said plurality of nodes such that each one of said plurality of nodes is able to maintain a database representing a topology of the optical network.

24. A method of operating an optical network, the optical network comprising a plurality of nodes connected by a plurality of links, comprising:

for each one of said plurality of nodes;

obtaining information from neighboring nodes, said information regarding a state of at least one of said plurality of links, and

using said information to maintain a database representing a topology of the optical network.

25. A method of testing a virtual path in an optical network, said virtual path provisioned on a physical path between a first and a second node of said optical network, said network comprising a plurality of nodes connected by a plurality of links, comprising:

testing said virtual path by testing each one of a plurality of nodes and a plurality of links in said physical path as a single circuit.

26. A computer program product encoded in computer readable media, the computer program product comprising:

first instructions, executable by a first processor, for identifying a first node and a second node of a plurality of nodes, said plurality of nodes being coupled by a plurality of links to form an optical network;

second instructions, executable by said first processor, for discovering a physical path from said first node to said second node by automatically identifying intermediary nodes of said physical path; and

third instructions, executable by said first processor, for establishing said virtual path by causing a second processor to configure a set of connections between said nodes of said physical path.

28. The computer program product of

claim 26

, further comprising:

fourth instructions, executable by said first processor, for testing said virtual path by testing each one of said plurality of nodes and said plurality of links of said physical path as a single circuit.

29. The computer program product of

claim 26

, further comprising:

fourth instructions, executable by said first processor, for terminating said virtual path by sending a termination message from one of said first and second nodes to the other of said first and second nodes, wherein said termination message is sent along said physical path and each one of said intermediary nodes is deallocated by a respective one of said nodes forming said physical path as said termination message is sent to a next one of said nodes.

30. The computer program product of

claim 26

, further comprising:

fourth instructions, executable by said first processor, for restoring said virtual path in response to a failure along said physical path by discovering an alternate physical path from said first node to said second node by automatically identifying nodes forming said alternate physical path, and re-establishing said virtual path by configuring a set of connections between said nodes of said alternate physical path.

32. A computer system comprising:

a display device;

a processor coupled to the display device;

computer readable medium coupled to the processor; and

computer code, encoded in the computer readable medium, for generating a graphical user interface, wherein the graphical user interface includes a first plurality of screen objects representing nodes of an optical network, a second plurality of screen objects representing optical links between said nodes, wherein;

a first one and a second one of said first plurality of screen objects are highlighted to indicate a source node and a destination node, respectively, and

certain ones of said first plurality of screen objects and certain ones of said second plurality of screen objects are highlighted by said computer code to indicate a virtual path selected by said computer code.

33. An optical network comprising:

a plurality of optical links;

a plurality of nodes, each one of said plurality of nodes coupled to at least one other of said plurality of nodes by at least one of said plurality of optical links, wherein said nodes are configured to provision a virtual path between a first node and a second node of said plurality of nodes by virtue of being configured to;

identify said first node and said second node of said plurality of nodes,

discover a physical path from said node to said second node by virtue of being configured to automatically identify any intermediary nodes of said physical path, and

establish said virtual path by virtue of being configured to configure a set of connections between said nodes of said physical path.

34. An optical network comprising:

a plurality of optical links;

a plurality of nodes, each one of said plurality of nodes coupled to at least one other of said plurality of nodes by at least one of said plurality of optical links, wherein said nodes are configured to restore a virtual path in said optical network, said virtual path being provisioned on a physical path between a first and a second node of said plurality of nodes by virtue of being configured to;

discover an alternate physical path from said first node to said second node by virtue of being configured to automatically identify nodes of said alternate physical path, and

re-establish said virtual path by virtue of being configured to configure a set of connections between said nodes of said alternate physical path.

35. A network comprising:

a plurality of nodes connected by a plurality of optical links, wherein said plurality of nodes are configured to provision a virtual path between a first node and a second node of said plurality of nodes, wherein each of said plurality of nodes comprises;

identifying means for identifying said first node and said second node of said plurality of nodes,

discovering means for discovering a physical path from said node to said second node by automatically identifying any intermediary nodes of said physical path, and

establishing means for establishing said virtual path by configuring a set of connections between said nodes of said physical path.

36. The network of

claim 35

, wherein seaid each one of said plurality of nodes further comprises:

restoring means for restoring said virtual path in response to a failure along said physical path comprising;

alternate discovering means for discovering an alternate physical path from said first node to said second node by automatically identifying intermediary nodes of said alternate physical path, and

re-establishing means for re-establishing said virtual path by configuring a set of connections between said nodes of said alternate physical path.

37. An optical network comprising:

a plurality of nodes connected by a plurality of optical links, wherein said plurality of nodes are configured to restore a virtual path in an optical network, said virtual path being provisioned on a physical path between a first and a second node of said plurality of nodes, wherein each one of said plurality of nodes comprises;

discovering means for discovering an alternate physical path from said first node to said second node by automatically identifying nodes of said alternate physical path, and

re-establishing means for re-establishing said virtual path by configuring a set of connections between said nodes of said alternate physical path.