Method and apparatus for load balancing over virtual network links

• US 20080031263A1
• Filed: 08/07/2006
• Published: 02/07/2008
• Est. Priority Date: 08/07/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Alexander, James, Ervin, Jimmy, Takefman, Mike, Faulkner, Steven, Bhagwatula, Praveen
• Granted Patent: US 7,580,417 B2
• Time in Patent Office: Days
• US Class Current: 370/397
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering

Abstract

Techniques for load balancing network traffic over virtual point-to-point data links at a data-link layer include determining a particular group of virtual point-to-point data links that reach a particular local area network of one or more network nodes. A particular data-link address for a particular node of the particular local area network is associated with each virtual point-to-point data link of the particular group. When a data packet is received that includes data that indicates the particular data-link address as a destination; one virtual point-to-point data link of the group is determined to balance traffic among the group. The data packet is sent only over the one virtual point-to-point data link. These techniques enable virtual point-to-point data links through two or more intermediate network nodes, such as a pair of provider edge nodes, to be bundled for load balancing purposes.

Claims

1. A method for load balancing network traffic over virtual point-to-point data links, comprising the steps of:

determining a particular plurality of virtual point-to-point data links at a data-link layer that reach a particular local area network of one or more network nodes;

associating a particular data-link address for a particular node of the particular local area network with each virtual point-to-point data link of the particular plurality of virtual point-to-point data links;

receiving a data packet that includes data that indicates the particular data-link address as a destination;

determining one virtual point-to-point data link of the particular plurality of virtual point-to-point data links to balance traffic among the particular plurality of virtual point-to-point data links; and

sending the data packet only over the one virtual point-to-point data link.

2. A method as recited in claim 1, wherein the particular plurality of virtual point-to-point data links are included in at least one of a virtual local area network (VLAN) and a virtual private network (VPN).

3. A method as recited in claim 1, said step of determining the particular plurality of virtual point-to-point data links that reach the particular local area network further comprising receiving configuration data that indicates the particular plurality of virtual point-to-point data links is a bundle for load-balancing.

4. A method as recited in claim 1, said step of determining the particular plurality of virtual point-to-point data links that reach the particular local area network further comprising receiving over a virtual point-to-point data link of the particular plurality of virtual point-to-point data links a control plane data packet that includes data that indicates a unique identifier for the particular plurality of virtual point-to-point data links.

5. A method as recited in claim 1, said step of associating a particular data-link address for the particular node with each virtual point-to-point data link further comprising the steps of:

receiving a data packet that includes data that indicates a first virtual point-to-point data link and a first data-link address as a source of the data packet;

determining whether the first virtual point-to-point data links is among the particular plurality of virtual point-to-point data links; and

if it is determined that the first virtual link-layer segment is among the particular plurality of virtual point-to-point data links, then performing the steps of

determining whether the first data-link address is associated with the first virtual point-to-point data link; and

if it is determined that the first data-link address is not associated with the first virtual point-to-point data link, then associating the first data-link address with the first virtual point-to-point data link without removing an association of the first data-link address with any other virtual point-to-point data links of the particular plurality of virtual point-to-point data links.

6. A method as recited in claim 5, said step of associating a particular data-link address for the particular node with each virtual point-to-point data link further comprising the steps of:

if it is determined that the first virtual point-to-point data link is not among the particular plurality of virtual point-to-point data links, then performing the steps of

determining whether the first data-link address is associated with the first virtual point-to-point data link; and

if it is determined that the first data-link address is not associated with the first virtual point-to-point data link, then performing the steps of;

associating the first data-link laddress with the first virtual point-to-point data link,

determining whether the first data-link address is associated with an other virtual point-to-point data link; and

if it is determined that the first data-link address is associated with the other virtual point-to-point data link, removing the first data-link address from association with the other virtual point-to-point data link.

7. A method as recited in claim 1, wherein a virtual point-to-point data link of the particular plurality of virtual point-to-point data links is encapsulated in a loop-free network protocol for transecting a plurality of data-link layer switches.

8. A method as recited in claim 7, wherein the loop-free network protocol is a resilient packet ring (RPR) protocol.

9. A method as recited in claim 7, wherein the loop-free network protocol is a multiple protocol label switching (MPLS) protocol.

10. A method as recited in claim 7, wherein the loop-free network protocol is a media access control (MAC)-in-MAC protocol.

11. A method as recited in claim 7, wherein the loop-free network protocol is a generic routing encapsulation (GRE) tunneling protocol.

12. An apparatus for load balancing network traffic over virtual point-to-point data links, comprising:

means for determining a particular plurality of virtual point-to-point data links at a data-link layer that reach a particular local area network of one or more network nodes;

means for associating a particular data-link address for a particular node of the particular local area network with each virtual point-to-point data link of the particular plurality of virtual point-to-point data links;

means for receiving a data packet that includes data that indicates the particular data-link address as a destination;

means for determining one virtual point-to-point data link of the particular plurality of virtual point-to-point data links to balance traffic among the particular plurality of virtual point-to-point data links; and

means for sending the data packet only over the one virtual point-to-point data link.

13. An apparatus for load balancing network traffic over virtual point-to-point data links, comprising:

a network interface coupled to a network for communicating therewith a data packet;

a computer-readable medium for storing information;

one or more processors; and

one or more sequences of instructions stored on the computer-readable medium, which, when executed by the one or more processors, causes the one or more processors to carry out the steps of;

determining a particular plurality of virtual point-to-point data links at a data-link layer that reach a particular local area network of one or more network nodes through the network interface;

associating a particular data-link address for a particular node of the particular local area network with each virtual point-to-point data link of the particular plurality of virtual point-to-point data links;

receiving a data packet that includes data that indicates the particular data-link address as a destination;

determining one virtual point-to-point data link of the particular plurality of virtual point-to-point data links to balance traffic among the particular plurality of virtual point-to-point data links; and

sending the data packet only over the one virtual point-to-point data link.

14. An apparatus as recited in claim 13, wherein the particular plurality of virtual point-to-point data links are included in at least one of a virtual local area network (VLAN) and a virtual private network (VPN).

15. An apparatus as recited in claim 13, said step of determining the particular plurality of virtual point-to-point data links that reach the particular local area network further comprising receiving configuration data that indicates the particular plurality of virtual point-to-point data links is a bundle for load-balancing.

16. An apparatus as recited in claim 13, said step of determining the particular plurality of virtual point-to-point data links that reach the particular local area network further comprising receiving over a virtual point-to-point data link of the particular plurality of virtual point-to-point data links a control plane data packet that includes data that indicates a unique identifier for the particular plurality of virtual point-to-point data links.

17. An apparatus as recited in claim 13, said step of associating a particular data-link address for the particular node with each virtual point-to-point data link further comprising the steps of:

receiving a data packet that includes data that indicates a first virtual point-to-point data link and a first data-link address as a source of the data packet;

determining whether the first virtual point-to-point data links is among the particular plurality of virtual point-to-point data links; and

if it is determined that the first virtual link-layer segment is among the particular plurality of virtual point-to-point data links, then performing the steps of

determining whether the first data-link address is associated with the first virtual point-to-point data link; and

if it is determined that the first data-link address is not associated with the first virtual point-to-point data link, then associating the first data-link address with the first virtual point-to-point data link without removing an association of the first data-link address with any other virtual point-to-point data links of the particular plurality of virtual point-to-point data links.

18. An apparatus as recited in claim 17, said step of associating a particular data-link address for the particular node with each virtual point-to-point data link further comprising the steps of:

if it is determined that the first virtual point-to-point data link is not among the particular plurality of virtual point-to-point data links, then performing the steps of

determining whether the first data-link address is associated with the first virtual point-to-point data link; and

if it is determined that the first data-link address is not associated with the first virtual point-to-point data link, then performing the steps of;

associating the first data-link laddress with the first virtual point-to-point data link,

determining whether the first data-link address is associated with an other virtual point-to-point data link; and

if it is determined that the first data-link address is associated with the other virtual point-to-point data link, removing the first data-link address from association with the other virtual point-to-point data link.

19. An apparatus as recited in claim 13, wherein a virtual point-to-point data link of the particular plurality of virtual point-to-point data links is encapsulated in a loop-free network protocol for transecting a plurality of data-link layer switches.

20. An apparatus as recited in claim 19, wherein the loop-free network protocol is a resilient packet ring (RPR) protocol.

21. An apparatus as recited in claim 19, wherein the loop-free network protocol is a multiple protocol label switching (MPLS) protocol.

22. An apparatus as recited in claim 19, wherein the loop-free network protocol is a media access control (MAC)-in-MAC protocol.

23. An apparatus as recited in claim 19, wherein the loop-free network protocol is a generic routing encapsulation (GRE) tunneling protocol.