System and method to facilitate the assignment of service functions for service chains in a network environment

1. A method comprising:

receiving a first Internet protocol (IP) flow for an IP session for a subscriber;

acquiring a service policy for the subscriber from a Policy and Charging Rules Function (PCRF), wherein the service policy identifies one or more service function chain types that can be associated with one or more IP flows for the subscriber;

selecting a first service function group from a plurality of service function groups to perform one or more services for the IP session for the subscriber, wherein each of the plurality of service function groups comprises a plurality of service function chain types and wherein each service function chain type comprises an ordered combination of one or more service functions;

assigning the IP session for the subscriber to the first service function group; and

forwarding the first IP flow for the IP session of the subscriber across a first service function chain type for the first service function group based, at least in part, on the service policy for the subscriber.

2. The method of claim 1 , the selecting further comprising:

retrieving loading information for each of the plurality of service function groups; and

determining the first service function group is available to support the IP session for the subscriber based, at least in part, on the loading information.

3. The method of claim 1 , wherein the acquiring is performed once per IP session for the subscriber.

4. The method of claim 3 , further comprising:

determining a first service function chain type to assign the first IP flow for the subscriber based on the service policy and flow information associated with the first IP flow;

mapping the first IP flow for the subscriber to a first service path identifier, wherein the first service path identifier identifies the first service function group and the first service function chain type; and

appending the first service path identifier to each IP packet of the first IP flow for the subscriber.

5. The method of claim 4 , wherein the appending includes encapsulating the first service path identifier in a Network Services Header (NSH) of each IP packet of the first IP flow.

6. The method of claim 5 , wherein the forwarding includes forwarding each IP packet of the first IP flow of the subscriber to each of one or more service functions associated with the first service function chain type.

7. The method of claim 6 , further comprising:

receiving a second IP flow for the IP session of the subscriber;

determining a second service function chain type for the first service function group based on the service policy for the subscriber and flow information associated with the second IP flow;

mapping the second IP flow for the subscriber to a second service path identifier, wherein the second service path identifier identifies the first service function group and the second service function chain type;

appending the second service path identifier to each IP packet of the second IP flow of the subscriber; and

forwarding the second IP flow of the subscriber across the second service function chain type according to the second service path identifier.

8. One or more non-transitory tangible media encoding logic that includes instructions for execution that when executed by a processor, is operable to perform operations comprising:

receiving a first Internet protocol (IP) flow for an IP session for a subscriber;

acquiring a service policy for the subscriber from a Policy and Charging Rules Function (PCRF), wherein the service policy identifies one or more service function chain types that can be associated with one or more IP flows for the subscriber;

selecting a first service function group from a plurality of service function groups to perform one or more services for the IP session for the subscriber, wherein each of the plurality of service function groups comprises a plurality of service function chain types and wherein each service function chain type comprises an ordered combination of one or more service functions;

assigning the IP session for the subscriber to the first service function group; and

forwarding the first IP flow for the IP session of the subscriber across a first service function chain type for the first service function group based, at least in part, on the service policy for the subscriber.

9. The media of claim 8 , the selecting further comprising:

retrieving loading information for each of the plurality of service function groups; and

determining the first service function group is available to support the IP session for the subscriber based, at least in part, on the loading information.

10. The media of claim 8 , wherein the acquiring is performed once per IP session for the subscriber.

11. The media of claim 10 , the operations further comprising:

determining a first service function chain type to assign the first IP flow for the subscriber based on the service policy and flow information associated with the first IP flow;

mapping the first IP flow for the subscriber to a first service path identifier, wherein the first service path identifier identifies the first service function group and the first service function chain type; and

appending the first service path identifier to each IP packet of the first IP flow for the subscriber.

12. The media of claim 11 , wherein the appending includes encapsulating the first service path identifier in a Network Services Header (NSH) of each IP packet of the first IP flow.

13. The media of claim 12 , wherein the forwarding includes forwarding each IP packet of the first IP flow of the subscriber to each of one or more service functions associated with the first service function chain type.

14. The media of claim 13 , the operations further comprising:

receiving a second IP flow for the IP session of the subscriber;

determining a second service function chain type for the first service function group based on the service policy for the subscriber and flow information associated with the second IP flow;

mapping the second IP flow for the subscriber to a second service path identifier, wherein the second service path identifier identifies the first service function group and the second service function chain type;

appending the second service path identifier to each IP packet of the second IP flow of the subscriber; and

forwarding the second IP flow of the subscriber across the second service function chain type according to the second service path identifier.

15. An apparatus, comprising:

a memory element for storing data; and

a processor for executing instructions associated with the data, wherein the executing causes the apparatus to perform operations, comprising:

receiving a first Internet protocol (IP) flow for an IP session for a subscriber;

acquiring a service policy for the subscriber from a Policy and Charging Rules Function (PCRF), wherein the service policy identifies one or more service function chain types that can be associated with one or more IP flows for the subscriber;

selecting a first service function group from a plurality of service function groups to perform one or more services for the IP session for the subscriber, wherein each of the plurality of service function groups comprises a plurality of service function chain types and wherein each service function chain type comprises an ordered combination of one or more service functions;

assigning the IP session for the subscriber to the first service function group; and

forwarding the first IP flow for the IP session of the subscriber across a first service function chain type for the first service function group based, at least in part, on the service policy for the subscriber.

16. The apparatus of claim 15 , the selecting further comprising:

retrieving loading information for each of the plurality of service function groups; and

determining the first service function group is available to support the IP session for the subscriber based, at least in part, on the loading information.

17. The apparatus of claim 15 , wherein the executing causes the apparatus to perform further operations, comprising:

determining a first service function chain type to assign the first IP flow for the subscriber based on the service policy and flow information associated with the first IP flow;

mapping the first IP flow for the subscriber to a first service path identifier, wherein the first service path identifier identifies the first service function group and the first service function chain type; and

appending the first service path identifier to each IP packet of the first IP flow for the subscriber.

18. The apparatus of claim 17 , wherein the appending includes encapsulating the first service path identifier in a Network Services Header (NSH) of each IP packet of the first IP flow.

19. The apparatus of claim 18 , wherein the forwarding includes forwarding each IP packet of the first IP flow of the subscriber to each of one or more service functions associated with the first service function chain type.

20. The apparatus of claim 19 , wherein the executing causes the apparatus to perform further operations, comprising:

receiving a second IP flow for the IP session of the subscriber;

determining a second service function chain type for the first service function group based on the service policy for the subscriber and flow information associated with the second IP flow;

mapping the second IP flow for the subscriber to a second service path identifier, wherein the second service path identifier identifies the first service function group and the second service function chain type;

appending the second service path identifier to each IP packet of the second IP flow of the subscriber; and

forwarding the second IP flow of the subscriber across the second service function chain type according to the second service path identifier.