Reliable message transfer over an unreliable network

• US 20070047453A1
• Filed: 08/24/2005
• Published: 03/01/2007
• Est. Priority Date: 08/24/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Rash, Karen, Rash, Nicholas, Bender, Carl, Ramanan, Aruna
• Granted Patent: US 8,018,844 B2
• Time in Patent Office: Days
• US Class Current: 370/244
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/54 Organization of routing tables

Abstract

In a communications network having a plurality of nodes adapted to communicate with each other, and more than one path available between most source-destination node-pairs, a network interface is associated with each node. Each network interface has a plurality of route tables for defining a plurality of routes for transferring each packet from a source node to a destination node. Each network interface further includes a path status table of path status indicators, e.g., bits, for indicating whether each route in the route tables is usable or is unusable as being associated with a fault. The network manager monitors the network to identify faults and provides the path status indicators to the respective network interfaces. Failed routes in the network are avoided based on the path status indicators. When a failed route is restored, such that the route is usable again, the path status table indicates that the usable state is restored. A balance of route usage in the network is maintained, without modifying routes or establishing different routes, enabling reliable and high-performance message transfer.

Claims

1. A communications network, comprising:

a plurality of nodes adapted to communicate by transmitting packets between source nodes and destination nodes;

a network interface associated with each node, each network interface defining a plurality of routes for transferring each packet from a source node to a destination node, each network interface further comprising path status indicators for indicating whether each route is usable or is unusable as being associated with a fault; and

a network manager for monitoring the network to identify faults therein and for providing the path status indicators to the respective network interfaces.

2. The communications network of claim 1, further comprising a plurality of route tables for defining the plurality of routes.

3. The communications network of claim 2, wherein each route table comprises a plurality of entries indexed by a destination identifier, each entry being associated with a respective route between a source node and a destination node.

4. The communications network of claim 2, comprising at least three route tables corresponding to each source node and destination node pair.

5. The communications network of claim 2, wherein the network manager determines the route tables and provides the route tables to the respective network interfaces.

6. The communications network of claim 1, further comprising a path status table comprising the path status indicators.

7. The communications network of claim 1, wherein the path status indicators comprise preferred bit indicators that toggle between preferred and non-preferred status.

8. The communications network of claim 1, wherein the network manager further determines repair actions for routes associated with identified faults.

9. A method for communicating among a plurality of nodes in a network, comprising:

defining a plurality of routes for transferring a packet from a source node to a destination node in the network;

monitoring the network to identify faults therein;

providing path status indicators for indicating whether each route is usable or is unusable as being associated with a fault; and

selecting a usable route for transferring the packet from the respective source node to the respective destination node.

10. The method of claim 9, further comprising providing route tables for the plurality of routes, each route table comprising a plurality of entries such that each entry is associated with a respective route between a source node and a destination node.

11. The method of claim 10, further comprising providing a destination identifier for indexing the entries in each route table.

12. The method of claim 10, comprising providing at least three route tables corresponding to each source node and destination node pair.

13. The method of claim 9, further comprising providing a table for the path status indicators.

14. The method of claim 9, wherein the path status indicators comprise preferred bit indicators that toggle between preferred and non-preferred status.

15. The method of claim 9, further comprising determining repair actions for routes associated with identified faults.

16. An article of manufacture, comprising:

at least one computer usable medium having computer readable program code means embodied therein for effecting communication among a plurality of nodes in a network, the computer readable program code means in the article of manufacture comprising;

computer readable code means for defining a plurality of routes for transferring a packet from a source node to a destination node in the network;

computer readable code means for monitoring the network to identify faults therein; and

computer readable code means for providing path status indicators for indicating whether each route is usable or is unusable as being associated with a fault; and

computer readable code means for selecting a usable route for transferring the packet from the respective source node to the respective destination node.

17. The article of manufacture of claim 16, further comprises computer readable code means for providing route tables for the plurality of routes, each route table comprising a plurality of entries such that each entry is associated with a respective route between a source node and a destination node.

18. The article of manufacture of claim 17, further comprising computer readable code means for providing a destination identifier for indexing the entries in each route table.

19. The article of manufacture of claim 17, further comprising computer readable code means for providing at least three route tables corresponding to each source node and destination node pair.

20. The article of manufacture of claim 16, further comprising computer readable code means for providing a table for the path status indicators.

21. The article of manufacture of claim 16, further comprising computer readable code means for determining repair actions for routes associated with identified faults.

22. At least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method for communicating among a plurality of nodes in a network, the method comprising:

defining a plurality of routes for transferring the packet from a source node to a destination node in the network;

monitoring the network to identify faults therein;

providing path status indicators for indicating whether each route is usable or is unusable as being associated with a fault; and

selecting a usable route for transferring the packet from the respective source node to the respective destination node.

23. The at least one program storage device of claim 22, further comprising providing route tables for the plurality of routes, each route table comprising a plurality of entries such that each entry is associated with a respective route between a source node and a destination node.

24. The at least one program storage device of claim 23, further comprising providing a destination identifier for indexing the entries in each route table.

25. The at least one program storage device of claim 23, comprising providing at least three route tables corresponding to each source node and destination node pair.

26. The at least one program storage device of claim 22, further comprising providing a table for the path status indicators.

27. The at least one program storage device of claim 22, further comprising determining repair actions for routes associated with identified faults.