Claims:WE CLAIM
1. A method of optimizing service function paths associated with common service functions, the method comprising:
identifying, by a network device, at least one proposed modification to a target Service Function Path (SFP) to in response to a trigger event;
for each of the at least one proposed modification made to the target SFP, determining, by the network device, at least one associated SFP impacted by an associated proposed modification, wherein the at least one associated SFP comprises at least one common service function with the target SFP;
determining, by the network device, at least one impact on each of the at least one associated SFP impacted by an associated proposed modification from the at least one proposed modification;
optimizing, by the network device, the at least one impact on each of the at least one associated SFP based on predefined impact criteria to generate an optimized set of impacts for each of the at least one associated SFP;
determining, by the network device, at least one action associated with each impact in the optimized set of impacts for each of the at least one associated SFP;
for each of the at least one associated SFP, optimizing, by the network device, the at least one action associated with each impact in the optimized set of impacts based on predefined action criteria to generate an optimized set of actions for each of the at least one associated SFP; and
reconfiguring, by the network device, the target SFP based on a proposed modification from the at least one proposed modification and triggering, for one or more of the at least one associated SFP, an associated optimized set of actions corresponding to the proposed modification.

2. The method of claim 1, further comprising receiving the trigger event requiring modification of the target SFP, wherein the trigger event comprises modification in an associated SFP comprising at least one common service function with the target SFP.

3. The method of claim 1, further comprising identifying the proposed modification from the at least one proposed modifications, wherein the proposed modification causes minimum number of impacts on associated SFPs and satisfies a selection criterion, wherein the selection criterion comprises at least one of minimum mandatory changes in associated SFPs and minimum network resource consumption.

4. The method of claim 1, further comprising determining remaining subsistence duration for the target SFP.

5. The method of claim 4, wherein determining the remaining subsistence duration for the target SFP comprises:
determining correlation between total subsistence duration for the target SFP based on a set of network and user parameters;
determining an average total subsistence duration for at least one SFP comprising at least one same served user common with the target SFP;
adapting the average total subsistence duration based on estimated network condition and a tuning factor to generate total subsistence duration for the target SFP; and
determining the remaining subsistence duration by subtracting the time elapsed since the instantiation of the target SFP from the adapted average total subsistence duration.

6. The method of claim 4, further comprising ignoring the at least one proposed modification to the target SFP, when the remaining subsistence duration for the target SFP is below a predefined SFP subsistence period.

7. The method of claim 1, wherein an impact from the at least one impact on an associated SFP is determined based on at least one of load and congestion level on the associated SFP during a past predefined time duration and average traffic and traffic spikes coming from the target SFP.

8. The method of claim 1, wherein, for an associated SFP from the at least one associated SFP, the predefined impact criteria comprises identifying a set of impacts from the at least one impact for the associated SFP, wherein one or more impacts from the set of impacts nullifies effect of one or more remaining impacts in the set of impacts.

9. The method of claim 1, wherein, for an associated SFP from the at least one associated SFP, the predefined action criteria comprise:
identifying a set of actions capable of nullifying each of the plurality of impacts for the associated SFP;
removing at least one action from the set of actions, wherein the at least one action reverses the effect of at least one counter action performed within a predefined time duration; and
determining the optimized set of actions for the associated SFP, wherein the optimized set of actions comprise remaining actions in the set of actions.

10. The method of claim 1, further comprising determining after a predefined assessment time interval, performance of the target SFP and performance of each of the one or more of the at least one associated SFP.

11. The method of claim 10 further comprising extracting learnings based on at least one of performance analysis for the target SFP post reconfiguring and performance analysis of the at least one associated SFP post triggering of the associated optimized set of actions, wherein the learnings are extracted for future optimization of service function paths associated with common service functions.

12. The method of claim 10, further comprising performing at least one corrective action, when performance of at least one of the target SFP and one of the one or more of the at least one associated SFP falls below expected performance criteria.

13. A network device for optimizing service function paths associated with common service functions, the network device comprising:
at least one processor; and
a memory communicatively coupled to the processor, wherein the memory stores processor instructions, which, on execution, causes the processor to:
identify at least one proposed modification to a target Service Function Path (SFP) in response to resolve a trigger event;
for each of the at least one proposed modification made to the target SFP, determine at least one associated SFP impacted by an associated proposed modification, wherein the at least one associated SFP comprises at least one common service function with the target SFP;
determine at least one impact on each of the at least one associated SFP impacted by an associated proposed modification from the at least one proposed modification;
optimize the at least one impact on each of the at least one associated SFP based on predefined impact criteria to generate an optimized set of impacts for each of the at least one associated SFP;
determine at least one action associated with each impact in the optimized set of impacts for each of the at least one associated SFP;
for each of the at least one associated SFP, optimize the at least one action associated with each impact in the optimized set of impacts based on predefined action criteria to generate an optimized set of actions for each of the at least one associated SFP; and
reconfigure the target SFP based on a proposed modification from the at least one proposed modification and triggering, for one or more of the at least one associated SFP, an associated optimized set of actions corresponding to the proposed modification.

14. The network device of claim 13, wherein the processor instructions further cause the processor to receive the trigger event requiring modification of the target SFP, wherein the trigger event comprises modification in an associated SFP comprising at least one common service function with the target SFP.

15. The network device of claim 13, wherein the processor instructions further cause the processor to identify the proposed modification from the at least one proposed modifications, wherein the proposed modification causes minimum number of impacts on associated SFPs and satisfies a selection criterion, wherein the selection criterion comprises at least one of minimum mandatory changes in associated SFPs and minimum network resource consumption.

16. The network device of claim 13, wherein the processor instructions further cause the processor to determine remaining subsistence duration for the target SFP.

17. The network device of claim 16, wherein to determine the remaining subsistence duration for the target SFP, the processor instructions further cause the processor to:
determine correlation between total subsistence duration for the target SFP based on a set of network and user parameters;
determine an average total subsistence duration for at least one SFP comprising at least one same served user common with the target SFP;
adapt the average total subsistence duration based on estimated network condition and a tuning factor to generate total subsistence duration for the target SFP; and
determine the remaining subsistence duration by subtracting the time elapsed since the instantiation of the target SFP from the adapted average total subsistence duration.

18. The network device of claim 16, wherein the processor instructions further cause the processor to ignore the at least one proposed modification to the target SFP, when the remaining subsistence duration for the target SFP is below a predefined SFP subsistence period.

19. The network device of claim 13, wherein the processor instructions further cause the processor to determine after a predefined assessment time interval, performance of the target SFP and performance of each of the one or more of the at least one associated SFP.

20. The network device of claim 19, wherein the processor instructions further cause the processor to extract learnings based on at least one of performance analysis for the target SFP post reconfiguring and performance analysis of the at least one associated SFP post triggering of the associated optimized set of actions, wherein the learnings are extracted for future optimization of service function paths associated with common service functions.

Dated this 29th day of March, 2018

R Ramya Rao
Of K&S Partners
Agent for the Applicant
IN/PA-1607
, Description:TECHNICAL FIELD
This disclosure relates generally to service function chains and more particularly to method and system for optimizing service function paths associated with common service functions.