Method and apparatus for routing data packets in a global IP network

• US 20080002588A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: McCaughan, Sherry L., Nguyen, Han Q., Saad, Samir, Uttaro, James
• Application Number:
  US11/478,892
• Publication Number:
  US 20080002588A1
• Time in Patent Office: Days
• US Class Current: 370/238
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/121 by minimising delays
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 47/10 Flow control; Congestion control

Abstract

A method and apparatus for optimally routing a data packet through multiple autonomous networks. A data packet received at an ingress node of a first autonomous network is routed to an egress node of a second autonomous network by selecting an optimal route based on the lowest latency using internal gateway protocol (IGP) routing information of the first and second autonomous networks, which is distributed to nodes of the first and second autonomous network. The data packet is then transmitted along the selected optimal route.

Claims

1. A method for routing a data packet through multiple autonomous networks, comprising:

receiving a data packet at an ingress node of a first autonomous network;

selecting an optimal route from said ingress node of the first autonomous network to an egress node of a second autonomous network using internal routing information of the first and second autonomous networks; and

transmitting said data packet along the selected route.

2. The method of claim 1, wherein the internal routing information comprises separate instances of internal gateway protocol (IGP) routing information in each autonomous network.

3. The method of claim 2, wherein said selecting step comprises:

analyzing header information of said data packet to determine a destination IP address;

determining a next hop of said destination IP address as a loopback interface address of said egress node of the second autonomous network based on external Border Gateway Protocol (eBGP) information exchanged between the first and second autonomous networks; and

selecting a route from said ingress node to said egress node based on said loopback interface address of said egress node using the IGP routing information of the first and second networks.

4. The method of claim 2, wherein said IGP routing information of each of the first and second autonomous networks comprises one of Open Shortest Path First (OSPF) routing information and Intermediate System to Intermediate System (IS-IS) routing information.

5. The method of claim 1, wherein said selecting step comprises:

calculating latency on a plurality of paths between said ingress node of the first autonomous network and said egress node of the second autonomous network using said internal routing information of the first and second autonomous networks; and

selecting a path between said ingress node of the first autonomous network and said egress node of the second autonomous network with the lowest latency.

6. The method of claim 1, wherein said selecting step comprises:

selecting a shortest path between said a shortest path between said ingress node of the first autonomous network and said egress node of the second autonomous network using the internal routing information of the first and second autonomous network.

7. The method of claim 1, wherein said transmitting step comprises:

assigning a label to the data packet based on the selected route using label binding information distributed in the first and second autonomous networks;

routing the data packet from said ingress node of the first autonomous network to said egress node of the second autonomous network along an optimal shortest latency-based path using Multiprotocol Label Switching (MPLS).

8. The method of claim 1, wherein said internal routing information of the second autonomous network is distributed to nodes of the first autonomous network.

9. The method of claim 1, wherein said selecting step comprises:

selecting a route from said ingress node of the first autonomous network to said egress node of the second autonomous network through a third autonomous network using internal routing information of the first, second, and third autonomous networks.

10. The method of claim 1, wherein said first and second autonomous networks correspond to geographical regions.

11. A network router of a first autonomous network for routing a data packet to an egress node of a second autonomous network, comprising:

an interface for receiving a data packet;

a memory storing internal routing information of the first and second autonomous networks;

means for selecting an optimal route through the first and second autonomous networks to the egress node of the second autonomous network using the internal routing information of the first and second autonomous networks; and

means for transmitting said data packet along the selected optimal route.

12. The network router of claim 11, wherein said internal routing information comprises internal gateway protocol (IGP) routing information.

13. The network router of claim 12, wherein said IGP information comprises one of Open Shortest Path First (OSPF) routing information and Intermediate System to Intermediate System (IS-IS) routing information.

14. The network router of claim 11, wherein said memory further stores label binding information of the first and second autonomous systems, further comprising:

means for assigning a label to said data packet based on the selected optimal route and said label binding information.

15. An autonomous IP network, comprising:

at least one border router configured to distribute internal routing information of the autonomous IP network to a neighboring autonomous network and to receive internal routing information of the neighboring autonomous network from the neighboring autonomous network; and

at least one edge router configured to route a data packet to a node of a neighboring autonomous network using the internal routing information of the autonomous IP network and the neighboring autonomous network.

16. The autonomous IP network of claim 15, wherein said internal routing information comprises internal gateway protocol (IGP) routing information.

17. The autonomous IP network of claim 16, wherein the IGP of each of the autonomous networks comprises one of Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS).

18. The autonomous IP network of claim 15, further comprising:

at least one route reflector configured to exchange external border gateway protocol (eBGP) information with a neighboring autonomous network.

19. The autonomous IP network of claim 15, wherein the internal routing information of the neighboring autonomous IP network distributed by said at least one border router comprises location information for at least one edge router in the neighboring autonomous network.

20. The autonomous IP network of claim 15, wherein said at least one edge router comprises a memory storing the received internal routing information of the neighboring autonomous network.