USING CONTEXT LABELS TO SCALE MAC TABLES ON COMPUTER NETWORK EDGE DEVICES

• US 20120198064A1
• Filed: 01/31/2011
• Published: 08/02/2012
• Est. Priority Date: 01/31/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Boutros, Sami, Tsier, Yuri, Sivabalan, Muthurajah, Mohapatra, Pradosh, Filsfils, Clarence, Bettink, John H. W., Martini, Luca
• Granted Patent: US 8,908,527 B2
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/502 Frame based

Abstract

In one embodiment, an access component of a local network edge device receives traffic, and generates a frame for the traffic that includes a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and a virtual circuit label corresponding to a particular virtual service of the traffic. The local network edge device forwards the frame towards the remote network edge device. In another embodiment, the frame may be received at a core component of the remote network edge device, an in response to the remote context label identifying an access component of the remote network edge device, forwarded to the access component, which determines the particular virtual service, and forwards the traffic from the frame out the access component towards an endpoint for the traffic.

Claims

1. A method, comprising:

receiving traffic at an access component of a local network edge device in a computer network; and

if the local network edge device is aware of a remote network edge device in the computer network used to reach a destination of the traffic,

generating a frame for the traffic, the frame comprising

a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

forwarding the frame from the local network edge device towards the remote network edge device.

2. The method as in claim 1, further comprising:

if the local network edge device is not aware of a remote network edge device in the computer network used to reach a destination of the traffic,

generating a multicast frame for the traffic, the multicast frame comprising

a multicast context label, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

multicasting the multicast frame from the local network edge device toward one or more remote network edge devices.

3. The method as in claim 1, wherein generating the frame further comprises:

inserting a local context label of the access component of the local network edge device which received the traffic in the frame.

4. The method as in claim 3, further comprising:

including the local context label within frames for the traffic until the particular network edge device becomes aware of the local context label.

5. The method as in claim 4, further comprising:

waiting a timeout period during which the local context label is not included within frames for the traffic; and

after the timeout period, again including the local context label within frames for the traffic to refresh the awareness of the remote network edge device of the local context label.

6. The method as in claim 1, further comprising:

receiving, by the local network edge device, the remote context label of the access component of the particular remote network edge device in a frame from the access component of the remote network edge device.

7. The method as in claim 1, further comprising:

receiving, by the local network edge device, the remote context label of the access component of the remote network edge device prior to receiving any frames from the access component of the remote network edge device.

8. The method as in claim 1, wherein the virtual service is one of either a virtual private local area network (LAN) service (VPLS) or a virtual private wire service (VPWS).

9. The method as in claim 1, wherein each access component is selected from a group consisting of:

a line card (LC), an interface, and a bundle.

10. The method as in claim 1, wherein the virtual circuit label and remote context label are a unified remote virtual circuit context label, wherein a first portion of the unified remote virtual circuit context label represents the remote context label, and a second portion represents the virtual circuit label.

11. A method, comprising:

receiving a frame of traffic at a core component of a remote network edge device in a computer network, the frame including a label stack with a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded and a virtual circuit label corresponding to a particular virtual service for traffic from the frame; and

in response to the remote context label of the label stack of the frame identifying the access component of the remote network edge device,

forwarding the frame to the access component of the remote network edge device,

determining the particular virtual service of the frame from the virtual circuit label, and

forwarding the traffic from the frame out the access component towards an endpoint for the traffic.

12. The method as in claim 11, further comprising:

in response to the remote context label of the label stack of the frame not identifying an access component of the remote network edge device,

determining that the remote context label corresponds to one of either a multicast label or an unknown address label,

forwarding the frame to all access components corresponding to the virtual service indicated by at least one of either the remote context label or the virtual circuit label,

in response to a non-responsible access component not being responsible for the endpoint for the traffic, dropping the frame at the non-responsible access component, and

in response to a responsible access component being responsible for the endpoint for the traffic, forwarding the traffic out the responsible access component toward the endpoint for the traffic.

13. The method as in claim 11, wherein the label stack of the frame further comprises a context label of an access component of a local network edge device that generated the frame, the method further comprising:

associating, by the access component of the remote network edge device, the local context label of the access component of the local network edge device with a source address of the traffic.

14. The method as in claim 13, further comprising:

receiving traffic from one or more network devices;

generating a second frame for the traffic, the second frame comprising

a remote context label that identifies an access component of the local network edge device to which the traffic is to be forwarded upon arrival at the local network edge device, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

forwarding the second frame out the core component of the remote network edge device towards the local network edge device.

15. The method as in claim 11, further comprising:

transmitting, to the local network edge device by the remote network edge device, the remote context label of the access component of the remote network edge device in a previous frame from the access component of the remote network edge device

16. The method as in claim 11, further comprising:

transmitting, to the local network edge device by the remote network edge device, the context label of the access component of the remote network edge device prior to any frames from the access component of the remote network edge device.

17. The method as in claim 11, wherein the virtual service is one of either a virtual private local area network (LAN) service (VPLS) or a virtual private wire service (VPWS).

18. The method as in claim 11, wherein each access component and core component is each selected from a group consisting of:

a line card (LC), an interface, and a bundle.

19. The method as in claim 11, wherein the virtual circuit label and remote context label are a unified remote virtual circuit context label, wherein a first portion of the unified remote virtual circuit context label represents the remote context label, and a second portion represents the virtual circuit label.

20. An apparatus, comprising:

an access component configured to receive traffic from one or more network devices;

a processor coupled to the access component and configured to execute processes; and

a memory configured to store a process executable by the processor, the process, when executed, operable to,

if the apparatus is aware of a remote network edge device in the computer network used to reach a destination of the traffic received from the one or more network devices,

generate a frame for the traffic, the frame comprising

a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

forward the frame from the apparatus towards the remote network edge device.

21. The apparatus as in claim 20, wherein the process, when executed, is further operable to,

if the local network edge device is not aware of a remote network edge device in the computer network used to reach a destination of the traffic,

generate a multicast frame for the traffic, the multicast frame comprising

a multicast context label, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

multicasting the multicast frame from the local network edge device toward one or more remote network edge devices.

22. The apparatus as in claim 20, wherein the frame further comprises a local context label of the access component of the apparatus.

23. An apparatus, comprising:

a core component configured to receive a frame, the frame including a label stack with a remote context label and a virtual circuit label corresponding to a particular virtual service for traffic from the frame;

as an access component configured to communicate traffic from the frame to one or more endpoints;

a processor coupled to the access component and configured to execute processes; and

a memory configured to store a process executable by the processor, the process, when executed, operable to

in response to the remote context label of the label stack of the frame identifying the access component, forward the frame to the access component, determine the particular virtual service of the frame from the virtual circuit label, and forward traffic from the frame out the access component towards an endpoint for the traffic.

24. The apparatus as in claim 23, wherein the process, when executed, is further operable to

in response to the remote context label of the label stack of the frame not identifying the access component, determine that the remote context label corresponds to one of either a multicast label or an unknown address label, forward the frame to all access components corresponding to the virtual service indicated by at least one of either the remote context label or the virtual circuit label, in response to a non-responsible access component not being responsible for the endpoint for the traffic, drop the frame at the non-responsible access component, and in response to a responsible access component being responsible for the endpoint for the traffic, forward the traffic out the responsible access component toward the endpoint for the traffic.

25. The apparatus as in claim 23, wherein the label stack of the frame further comprises a local context label of an access component of a local network edge device that generated the frame, and wherein the process, when executed, is further operable to

associate the local context label of the access component of the local network edge device with a source address of the traffic.

26. The apparatus as in claim 25, wherein the access component of the apparatus is further configured to receive traffic from one or more network devices and the process, when executed, is further operable to

generate a second frame for the traffic, the second frame comprising

a remote context label that identifies an access component of the local network edge device to which the traffic is to be forwarded upon arrival at the local network edge device, and

a virtual circuit label corresponding to a particular virtual service of the traffic, and

forward the second frame out the core component of the apparatus towards the local network edge device.