Distributed label switching router

• US 6,947,428 B1
• Filed: 06/14/2000
• Issued: 09/20/2005
• Est. Priority Date: 06/14/2000
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Mattson, Geoffery A., Andersson, Loa
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): NGUYEN, SON XUAN
• Application Number:
  US09/869,679
• Time in Patent Office: 1,924 Days
• Field of Search: 370/230, 370/236, 370/248, 370/238, 370/395.5, 370/395.51, 370/401, 370/466, 370/467, 370/410, 709/227, 709/228, 709/229, 709/245
• US Class Current: 370/395.5
• 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 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A distributed LSR sends data from a first edge LSR, across a non-MPLS network, to a second edge LSR, thereby enabling a non-MPLS network to interface transparently with MPLS networks. This enables a VPN to use a public network to communicate from one portion of the network to another, remote portion. The distributed LSR includes an ingress gateway logically positioned between the first edge LSR and the non-MPLS network. This ingress gateway receives label requests from the first edge LSR. These label requests are multicast to several egress gateways. At least one egress gateway sends a message back indicating that it can transmit data to the destination. In response, the ingress gateway designates that egress gateway to be a designated gateway. The egress gateway then establishes a tunnel through the non-MPLS network to the ingress gateway.

Claims

1. A distributed label-switching-router for sending a data packet from a first edge label-switching-router, across a non-multi-protocol-label-switching network, to a second edge label-switching-router, said distributed label-switching-router comprising:

an ingress gateway logically positioned between said first edge label-switching-router and said non-multi-protocol-label-switching network, said ingress gateway receiving a label request from said first edge label-switching-router;

a multicast agent in communication with said ingress gateway and said non-multi-protocol-label-switching network for relaying said label request from said ingress gateway, across said non-multi-protocol-label-switching network, to a plurality of egress gateways, and for relaying at least one response from said plurality of egress gateways, across said non-multi-protocol-label-switching network, to said ingress gateway; and

a designated gateway from said plurality of egress gateways, said designated gateway being logically positioned between said second edge label-switching-router and said non-multi-protocol-label-switching network.

2. The distributed label-switching-router of claim 1 wherein said non-multi-protocol-label-switching network is an internet protocol network.

3. The distributed label-switching-router of claim 2 further comprising an ingress internet protocol router logically positioned between said ingress gateway and said multicast agent.

4. The distributed label-switching-router of claim 2 further comprising an egress internet protocol router logically positioned between said egress gateway and said internet protocol network.

5. The distributed label-switching-router of claim 1 wherein said ingress gateway further comprises a timer for detecting the lapse of a predetermined interval following transmission of said label request.

6. The distributed label-switching-router of claim 1 wherein said multicast agent further comprises a table providing information indicative of which egress gateways from said plurality of egress gateways are associated with a virtual private network.

7. The distributed label-switching-router of claim 1 further comprising confirmation means for sending a confirmation message designating said designated gateway from said plurality of egress gateways.

8. The distributed label-switching-router of claim 7 wherein said confirmation means comprises means for sending said confirmation message to all egress gateways responding to said label request message.

9. The distributed label-switching-router of claim 7 wherein said confirmation means comprises means for sending said confirmation message to those egress gateways, other than said designated gateway, responding to said label request message.

10. The distributed label-switching-router of claim 1 further comprising selection means for selecting a designated gateway on the basis of said at least one response from said plurality of egress gateways.

11. The distributed label-switching-router of claim 1 further comprising selection means for selecting a designated gateway from a plurality of responses from said plurality of egress gateways.

12. The distributed label-switching-router of claim 1 wherein said designated gateway further comprises means for establishing a tunnel across said non-multi-protocol-label-switching network.

13. A method for sending a data packet from a first edge label-switching-router, across a non-multi-protocol-label-switching network, to a second edge label-switching-router, said method comprising:

receiving a label request from said first edge label-switching-router;

multicasting said label request, across said non-multi-protocol-label-switching network, to a plurality of egress gateways;

receiving at least one response from at least one egress gateway from said plurality of egress gateways, said at least one response indicative of a communication path between said second edge label-switching-router and said at least one egress gateway; and

designating said at least one egress gateway to be a designated gateway for communication between said first edge label-switching-router and said second edge label-switching-router.

14. The method of claim 13 further comprising establishing a tunnel across said non-multi-protocol-label-switching network.

15. The method of claim 13 further comprising detecting a lapse of a predetermined interval following said multicasting of said label request.

16. The method of claim 13 further comprising determining which egress gateways from said plurality of egress gateways are associated with a virtual private network.

17. The method of claim 13 further comprising confirming said designated gateway by sending a confirmation message to said plurality of egress gateways, said confirmation message being indicative of said designated gateway from said plurality of egress gateways.

18. The method of claim 17 wherein confirming said designated gateway comprises sending said confirmation message to all egress gateways responding to said label request message.

19. The method of claim 17 wherein confirming said designated gateway comprises sending said confirmation message to those egress gateways, other than said designated gateway, responding to said label request message.

20. The method of claim 13 further comprising selecting a designated router on the basis of said at least one response from said plurality of egress gateways.

21. The method of claim 13 further comprising selecting a designated router from a plurality of responses from said plurality of egress gateways.