Service Selection Mechanism In Service Insertion Architecture Data Plane

• US 20100165985A1
• Filed: 12/29/2008
• Published: 07/01/2010
• Est. Priority Date: 12/29/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sharma, Govind, Durazzo, Kenneth, Quinn, Paul
• Granted Patent: US 8,442,043 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2425 for supporting services specification, e.g. SLA

Abstract

As described herein, explicit service ordering information may be associated with each of a plurality of logical services in a service path. A unique sequence number, for example, may be assigned, and associated with each service in the path. The sequence number may be assigned by a service broker in the control plane of a service insertion architecture that provides a platform-independent framework to insert services into a network. The sequence number may represent the relative ordering of the service with respect to the other services in the path. The sequence number, along with a traffic classification identifier, constitutes the shared context that is tagged to the packet injected into the chain which is used in the SIA data plane to virtualize and uniquely select series of services defined in the policy.

Claims

1. A method for providing service selection in a service insertion architecture data plane, the method comprising:

generating, at a first service node, a first packet that includes unique service ordering information associated with a first logical service performed at the first service node;

providing the first packet to a forwarding plane in the service insertion architecture;

providing the first packet to a second service node that is identified by the forwarding plane as a next hop location based on the unique service ordering information included in the first packet.

2. The method of claim 1, wherein the first logical service is one of a plurality of logical services in a service path.

3. The method of claim 1, wherein a second logical service in the service path is performed at the second service node.

4. The method of claim 1, wherein the service forwarding information includes a classification identifier associated with the service path, and a sequence number associated with an ordering of the first service in the service path.

5. The method of claim 4, wherein the classification identifier is allocated dynamically by a control plane element.

6. The method of claim 4, wherein the sequence number is allocated dynamically by a control plane element.

7. The method of claim 4, further comprising:

generating, at the second service node, a second packet that includes a classification identifier associated with the service path, and a sequence number associated with an ordering of the second service in the service path.

8. The method of claim 1, wherein the forwarding plane maintains a switching table from which the next hop location is determined based on the unique service ordering information included in the first packet.

9. The method of claim 8, wherein the switching table is implemented in an access control list (“

ACL”

) ternary content addressable memory (“

TCAM”

).

10. A method for providing service selection in a service insertion architecture data plane, the method comprising:

receiving a first packet that includes a service identifier associated with a traffic class, from which a service context and path are derived, the service path comprising a uniquely ordered plurality of logical services, the first packet further including a first sequence number;

performing a logical service after receiving the first packet;

generating a second packet that includes the original traffic class identifier and a second sequence number, wherein the second sequence number is different from the first sequence number; and

providing the second packet to a forwarding plane in the service insertion architecture.

11. The method of claim 10, wherein the forwarding plane stores in a switching table a corresponding context and next hop information for each of a plurality of path segments that form the service path.

12. The method of claim 11, wherein each context is defined by a unique service identifier and sequence number.

13. The method of claim 12, wherein the forwarding plane uses the traffic class identifier and sequence number provided in the received first packet to look up the switching table and determine a next hop location.

14. The method of claim 13, wherein the forwarding plane provides the second packet to the next hop location.

15. The method of claim 14, wherein the next hop location is an in-box service module slot or port.

16. The method of claim 14, wherein the next hop location is a tunnel to an out-of-box service.

17. A method for providing service selection in a service insertion architecture data plane, the method comprising:

receiving a first packet associated with performing a first logical service in a service path, the first packet containing first context information associated with the first logical service, the first context information including a unique combination of traffic class identifier and service sequence number;

determining a next hop location based on the first context information;

updating the context information in the packet to include a different service sequence number; and

sending the updated packet to a forwarding plane for service chaining to the next hop location.

18. The method of claim 17, wherein each logical hop in the service path updates the service header in the packet with its own service sequence number before sending it to the forwarding plane for service chaining to the next hop.

19. The method of claim 18, wherein the forwarding plane uses the context information to determine the next hop location.

20. The method of claim 19, wherein the next hop location is an in-box service module slot/port, or a tunnel to out-of-box service.