Internet protocol relay network for directly routing datagram from ingress router to egress router

• US 5,996,021 A
• Filed: 05/20/1997
• Issued: 11/30/1999
• Est. Priority Date: 05/20/1997
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Civanlar, Seyhan, Saksena, Vikram R.
• Primary Examiner(s): Dinh, Dung C.
• Application Number:
  US08/859,315
• Time in Patent Office: 924 Days
• Field of Search: 370/389, 370/392, 370/351, 370/352, 370/357, 395/200.66, 395/200.68, 395/200.69, 395/200.7, 395/200.71, 395/200.72, 395/200.73, 395/200.74, 395/200.75, 709/238, 709/242, 709/243, 709/244
• US Class Current: 709/238
• CPC Class Codes: H04L 12/4608 LAN interconnection over ATM networks
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04L 2012/5668 Next hop resolution protocol [NHRP]
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

An internetwork relay system and method for transmitting IP traffic including an edge and a core. The edge includes an ingress and egress routers and the core includes a switch network. The ingress router communicates with and receives an IP packet from a source network. The ingress router attaches to each IP packet, a globally unique label which is used to forward the IP packet across the network. The relay switch network communicates with the ingress router, receives the IP packet from the ingress router and forwards the IP packet along its transmission path based on destination information included in its attached label. The egress router receives the IP packet from the switch network and forwards it to a destination network. Once received, the destination network forwards the IP packet to its intended destination.

Claims

1. An internetwork relay system for transmission of internet protocol traffic along a transmission path in a network from a source to a destination, said system comprising:

an ingress router communicating with said source and receiving said datagram from said source;

a globally unique label identifying said destination used to forward said datagram across said network, said label attached to said datagram at said ingress router;

a relay switch network communicating with said ingress router and receiving said datagram therefrom based on information included in said label, said switch network forwarding said datagram along said transmission path based on information included in said label; and

an egress router receiving said datagram from said relay switch network and forwarding said datagram to said destination based on information included in said label.

2. The internetwork relay system of claim 1 wherein said relay switch network includes a plurality of relay switches, said switch network forwarding said datagram from said ingress router to said egress router such that said egress router is one router hop away from said ingress router.

3. The internetwork relay system of claim 2 wherein said label attached to said datagram is processed as read-only by each of said switches.

4. The internetwork relay system of claim 2 wherein each of said switches includes a forwarding table stored in a memory device, said forwarding table including routing information corresponding to said destination of said datagram, each of said switches reading said label, matching said destination information included in said label with said routing information contained in said forwarding table and forwarding said datagram along said transmission path toward said egress router based on said routing information.

5. The internetwork relay system of claim 1 wherein said ingress router includes a routing table stored in a memory containing said destination information and identification information corresponding to said egress router.

6. The internetwork relay system of claim 2 wherein one of said switches within said relay switch relay network communicating with said egress router along said datagram transmission path is an egress switch, said ingress router including a routing table stored in a memory device containing identification information corresponding to said egress switch.

7. The internetwork relay system of claim 6 wherein said routing table further includes identification information corresponding to a port on said egress switch through which said egress router communicates.

8. The internetwork relay system of claim 2 wherein said ingress router includes a forwarding table stored in a memory device containing identification information corresponding to said egress router.

9. The internetwork relay system of claim 2 wherein said ingress router includes a forwarding table stored in a memory device containing identification information corresponding to a port on said egress switch that communicates with said egress router.

10. The internetwork relay system of claim 2 wherein said ingress router includes a forwarding table stored in a memory device containing identification information corresponding to said egress switch.

11. The internetwork relay system of claim 5 wherein said routing table is updated dynamically upon the addition of a relay switch to said internetwork relay system.

12. The internetwork relay system of claims 6 wherein said routing table is updated dynamically upon the addition of a relay switch to said internetwork relay system.

13. The internetwork relay system of claim 6 wherein said routing table is updated dynamically upon the addition of a relay switch to said internetwork relay system.

14. The internetwork relay system of claim 5 wherein said routing table is updated dynamically upon the addition of an egress router to said internetwork relay system.

15. The internetwork relay system of claim 6 wherein said routing table is updated dynamically upon the addition of an egress router to said internetwork relay system.

16. The internetwork relay system of claim 7 wherein said routing table is updated dynamically upon the addition of an egress router to said internetwork relay system.

17. The internetwork relay system of claim 6 wherein said label includes identification information corresponding to said egress router.

18. The internetwork relay system of claim 6 wherein said label includes identification information corresponding to said egress switch and identification information corresponding to a particular port on said egress switch communicating with said egress router.

19. The internetwork relay system of claim 18 wherein said label further includes flow identification information for differentiating between multiple datagrams routed to the same destination.

20. The internetwork relay system of claim 18 wherein said label further includes flow identification information for balancing datagram traffic across multiple transmission paths.

21. The internetwork relay system of claim 1 wherein said switching network includes an asynchronous transfer mode switch.

22. The internetwork relay system of claim 1 wherein said ingress router attaches said label to said datagram using network layer processing.

23. The internetwork relay system of claim 1 wherein said egress router removes said label from said datagram using network layer processing.

24. The internetwork relay system of claim 1 wherein said label is partitioned to include information related to the location of said destination.

25. A method for transmitting Internet Protocol (IP) packets across a relay network, said packets originating from a source and forwarded to a destination, said method comprising the steps of:

receiving said IP packet from said source;

forwarding said IP packet from said source to an ingress router based on address information included in said IP packet;

parsing out said IP packet at said ingress router in order to read the address of said destination;

appending a unique label to said IP packet at said ingress router, said label including identification information related to the address of said destination;

forwarding said IP packet from said ingress router to a switching network; and

forwarding said IP packet from said switching network to an egress router such that said ingress router is one router hop away from said egress router.

26. The method of claim 25 further comprising the step of removing said label from said IP packet at said egress router.

27. The method of claim 26 further comprising the step of reassembling said IP packet at said egress router.

28. The method of claim 25 further comprising the step of forwarding said IP packet from said egress router to said destination.

29. The method of claim 25 wherein said ingress router includes a routing table stored in a memory device, said routing table including address information corresponding to said egress router.

30. The method of claim 25 wherein said ingress router includes a routing table stored in a memory device, said routing table including address information for said switching network corresponding to said destination address.

31. The method of claim 30 wherein said routing table further includes identification information associated with a port of said switch network communicating with said egress router.

32. The method of claim 29 further comprising the step of including in said label, address information corresponding to said egress router, said address information contained in said routing table.

33. The method of claim 25 wherein said ingress router includes a forwarding table stored in a memory device, said forwarding table including address information related to said information corresponding to said destination address, said method further comprising the step of mapping said destination address to said address information corresponding to said egress router.

34. The method of claim 29 wherein said switch network includes a plurality of relay switches, each of said switches including a forwarding table, said table including information corresponding to said egress router.

35. The method of claim 34 wherein said forwarding table includes port identification information corresponding to a port in said switches communicating with said egress router.

36. The method of claim 29 further comprising the step of updating said routing table dynamically each time a router is added to said network.

37. The method of claim 30 further comprising the step of updating said routing table dynamically each time a router is added to said network.

38. The method of claim 33 further comprising the step of updating said forwarding table dynamically each time a router is added to the network.

39. The method of claim 34 further comprising the step of updating said forwarding table dynamically each time a switch is added to said network.

40. An internetwork relay system for transmission of internet protocol traffic along a transmission path, said system including a source network and a destination network, said system comprising:

an ingress router communicating with said source network and receiving an internet protocol packet from said source network;

a label attached to said packet at said ingress router, said label including information corresponding to said destination network;

a switch network communicating with said ingress router and receiving said packet therefrom, said switch network forwarding said packet based on destination information included in said label;

an egress router receiving said packet from said switch network such that said egress router is one router hop away from said ingress router, said egress router forwarding said packet to said destination network.

41. The system of claim 40 wherein said switch network includes a plurality of relay switches, each of said switches including a forwarding table, said table including information related to one or more of said plurality of switches located on said transmission path.

42. The system of claim 40 wherein each of said forwarding tables include information corresponding to said destination network.

43. The system of claim 42 wherein said label uniquely identifies said destination.

44. The system of claim 43 wherein said label is viewed by said switch network as read only.