Method and apparatus for routing data using router identification information

• US 6,275,492 B1
• Filed: 12/02/1997
• Issued: 08/14/2001
• Est. Priority Date: 12/03/1996
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Zhang, Zhaohui
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US08/982,873
• Time in Patent Office: 1,351 Days
• Field of Search: 370/389, 370/392, 370/397, 370/399, 370/409, 370/401, 370/238, 370/236, 370/351, 370/352, 370/400, 370/406, 370/407, 370/408, 709/239, 709/240, 709/241, 709/238
• US Class Current: 370/392
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/03 by updating link state protocols
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/566 Routing instructions carried by the data packet, e.g. active networks

Abstract

A system for routing data through a network determines whether router identification information is associated with the data. The system then identifies a next hop router from a router table if router identification information is associated with the data. Otherwise, the system identifies a next hop router from a routing table if router identification information is not associated with the data. When identifying a next hop router from the router table, the system determines whether a match exists between entries in the router table and the router identification information. The system may set a switch tag in the data packet, in which the switch tag corresponds to a destination router identification. The router table used by the system contains information regarding how to reach all known routers.

Claims

1. A method of routing data through a network, the method comprising:

determining whether router identification information is associated with the data;

identifying a next hop router from a router table if router identification information is associated with the data, the router table including all known routers; and

identifying a next hop router from a routing table containing a destination and a route to the destination if router identification information is not associated with the data the routing table being generated by a router.

2. The method of claim 1 further comprising identifying a next hop router from the routing table if a next hop router cannot be identified from the router table using the router identification information.

3. The method of claim 1 further comprising setting a switch tag associated with the data, wherein the switch tag corresponds to a destination router identification.

4. The method of claim 1 wherein the router table contains information regarding how to reach all known routers.

5. The method of claim 1 wherein the routing table comprises information regarding a destination router capable of sending the data to a destination.

6. The method of claim 1 wherein the routing table comprises information regarding a destination router capable of sending the data to another network area.

7. The method of claim 1 wherein identifying the next hop router from the router table comprises determining whether a match exists between entries in the router table and the router identification information.

8. The method of claim 1 wherein the data is contained in a data packet and the router identification information is contained in the data packet.

9. The method of claim 1 wherein the method is performed by a network routing device.

10. The method of claim 1 wherein the method is performed by a switching system product.

11. The method of claim 1 wherein the method is performed by a transmission system product.

12. A router in a network comprising:

a routing table containing a destination and a route to the destination, the routing table being generated by the router;

a router table including all known routers; and

a routing engine coupled to the routing table and the router table, the routing engine being configured to forward data toward the destination in response to router identification information associated with the data and to identify a next hop router from the router table if the router table and the data contain the router identification information.

14. A router of claim 12 wherein the router operates in a switching system product.

15. The router of claim 12 wherein the router operates in a transmission system product.

13. A router in a network comprising:

a routing table containing a destination and a route to the destination, the routing table being generated by the router;

a router table including all known routers; and

a routing engine coupled to the routing table and the router table, the routing engine being configured to forward data toward the destination in response to router identification information associated with the data and to identify a next hop router from the routing table if the data and the router table do not contain the router identification information.

16. A routing apparatus comprising:

means for determining whether router identification information is associated with data;

means for identifying a next hop router from a router table if router identification information is associated with the data, wherein the router table includes all known routers; and

means for identifying a next hop router from a routing table containing a destination and a route to the destination if router identification information is not associated with the data, the routing table being generated by the routing apparatus.

17. The routing apparatus of claim 16 further comprising means for identifying a next hop router from the routing table if the next hop router cannot be identified from the router table using the router identification information.

18. The routing apparatus of claim 16 further comprising means for setting a switch tag associated with the data, wherein the switch tag corresponds to a destination router identification.

19. The routing apparatus of claim 16 wherein the router table contains information regarding how to reach all known routers.

20. The routing apparatus of claim 16 wherein the routing table comprises information regarding a destination router capable of sending the data to another network area.

21. The routing apparatus of claim 16 wherein the apparatus is a switching system product.

22. The routing apparatus of claim 16 wherein the apparatus is a transmission system product.

23. A computer software product comprising a medium readable by a processor, the medium having stored thereon a sequence of instructions which, when executed by the processor, causes the processor to:

determine whether router identification information is associated with received data;

identify a next hop router from a router table if router identification information is associated with the received data; and

identify a next hop router from a routing table containing a destination and a route to the destination if router identification information is not associated with the received data, the routing table being generated by a router.

24. The computer software product of claim 23 further comprising a sequence of instructions which, when executed by the processor, causes the processor to identify a next hop router from the routing table if a next hop router cannot be identified from the router table using the router identification information.

25. The computer software product of claim 23 further comprising a sequence of instructions which, when executed by the processor, causes the processor to set a switch tag associated with the data, wherein the switch tag corresponds to a destination router identification.

26. The computer software product of claim 23, wherein the router table contains information regarding how to reach all known routers.

27. The computer software product of claim 23 wherein the instructions are executed by a network routing device.

28. The computer software product of claim,23 wherein the instructions are executed by a switching system product.

29. The computer software product of claim 23 wherein the instructions are executed by a transmission system product.