ROUTING PROTOCOLS WITH PREDICTED OUTAGE NOTIFICATION

• US 20100232445A1
• Filed: 05/26/2010
• Published: 09/16/2010
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Bellovin, Steven
• Granted Patent: US 7,907,517 B2
• Time in Patent Office: Days
• US Class Current: 370/410
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A method for the efficient routing of data packets across a plurality of routers when a link is unavailable which includes connecting a plurality of nodes in a network using a plurality of routers having a plurality of links between the routers, informing the routers in the network when one or more of the links in the network will be unavailable at a specified time in the future, recalculating the routing tables to determine the most efficient routing paths when the links in the network become unavailable and, when the time in the future arrives, switching the routers in the network to the new routing tables at the same time.

Claims

1-21. -21. (canceled)

22. A computer-readable medium comprising instructions that, when executed by a processing device, cause the processing device to manage the routing of data packets across a plurality of routers in a network when a link is unavailable by:

determining the connectivity of a plurality of nodes in the network, wherein the nodes are connected using a plurality of routers having a plurality of links between said routers, wherein data packets can be sent between nodes in the network via a plurality of paths, wherein each path passes through a different combination of routers and links and each router has a routing table which is recalculated at intervals using a routing protocol to provide the most efficient routing paths;

informing a selected router that one or more of the links in the network will be unavailable at a specified time in the future;

transmitting a message from the selected router containing information about the one or more links that will be unavailable at a specified time in the future;

polling of the selected router by routers in the network in order to obtain additional information about the unavailability of the link or links at a specified time in the future; and

recalculating the routing table in each router to determine the most efficient routing paths at the time in the future when one or more of the links in the network will be unavailable.

23. The computer-readable medium for the routing of data packets across a plurality of routers according to claim 22, further comprising synchronizing the time when a link will be unavailable using a standard time synchronization protocol.

24. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the selected router is informed of the unavailability of one or more links in the network by an alarm signal.

25. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the selected router is informed of the unavailability of one or more links in the network by a signal entered manually by an operator.

26. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the message transmitted by the selected router relates to a metric change in the routing protocol.

27. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the plurality of routers in the network switch to new routing tables at the same time.

28. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the message is transmitted from the selected router to the other routers in the network.

29. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, wherein the network comprises a network operations center and the message is transmitted from the selected router to the network operations center.

30. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 29, wherein the network operations center selects the time when the routers are switched to the recalculated routing tables.

31. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 22, further comprising repairing or performing maintenance work during the time in the future when one or more of the links will be unavailable.

32. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 31, further comprising:

informing the selected router that one or more of the links in the network will be available at a specified time in the future;

transmitting a message from the selected router to the other routers in the network containing information about the one or more links that will be available at a specified time in the future;

recalculating the routing table in each router to determine the most efficient routing paths at the time in the future when one or more of the links in the network will be available; and

switching the plurality of routers in the network to new routing tables at the same time.

33. A computer-readable medium comprising instructions that, when executed by a processing device, cause the processing device to manage the routing of data packets across a plurality of routers in a network when a link is unavailable by:

determining the connectivity of a plurality of nodes in the network, wherein the nodes are connected using a plurality of routers having a plurality of links between said routers, wherein data packets can be sent between nodes in the network via a plurality of paths, wherein each path passes through a different combination of routers and links and each router has a routing table which is recalculated at intervals using a routing protocol to provide the most efficient routing paths;

informing a selected router that one or more of the links in the network will be unavailable at a specified time in the future;

transmitting a message from the selected router containing information about the one or more links that will be unavailable at a specified time in the future;

synchronizing the time when a link will be unavailable using a standard time synchronization protocol;

polling of the selected router by other routers in the network in order to obtain additional information about the unavailability of the link or links;

recalculating the routing table in each router to determine the most efficient routing paths at the time in the future when one or more of the links in the network will be unavailable; and

repairing or performing maintenance work during the time in the future when one or more of the links will be unavailable.

34. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the selected router is informed of the unavailability of one or more links in the network by an alarm signal.

35. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the selected router is informed of the unavailability of one or more links in the network by a signal entered manually by an operator.

36. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the selected router is informed of the unavailability of one or more links in the network by a metric change in the routing protocol.

37. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the plurality of routers in the network switch to new routing tables at the same time.

38. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the message is transmitted from the selected router to the other routers in the network.

39. The computer-readable medium method for the routing of data packets across a plurality of routers according to claim 33, wherein the network comprises a network operations center and the message is transmitted from the selected router to the network operations center.

40. A system for managing the routing of data packets across a plurality of routers in a network when a link is unavailable, the system comprising

a plurality of nodes in the network;

a plurality of routers, wherein the routers are used for communications between the nodes, and wherein each router has a routing table which is recalculated at intervals using a routing protocol to provide the most efficient routing paths;

a plurality of links between said routers;

a processing device for managing the routing of data packets across the plurality of routers in the network via a plurality of paths, wherein each path passes through a different combination of routers and links and wherein the processing device;

determines the connectivity of the plurality of nodes in the network;

informs a selected router that one or more of the links in the network will be unavailable at a specified time in the future;

transmits a message from the selected router containing information about the one or more links that will be unavailable at a specified time in the future;

wherein the selected router is polled by routers in the network in order to obtain additional information about the unavailability of the link or links at a specified time in the future; and

the routing table in each router is recalculated to determine the most efficient routing paths at the time in the future when one or more of the links in the network will be unavailable.

41. The system for managing the routing of data packets across a plurality of routers in a network when a link is unavailable according to claim 40, the system further comprising a standard time synchronization protocol for synchronizing the time when a link will be unavailable.