Dear Sharath Kumar,

to achieve Fault Tolerance in SDN, SDN Controllers must be designed redundantly and networked accordingly.

Two (or more) SDN Controllers could be paired together so that they act as a "Virtual SDN Controller". On one such idea is based the "Virtual Router" concept according to the Virtual Router Redundancy Protocol (VRRP). You can try adapting the VRRP idea for the SDN controllers.

For VRRP idea see Figures 4484 and 4485 at the address:

https://www.researchgate.net/publication/301675817_VRRP_Virtual_Router_Redundancy_Protocol

Enclosed very good papers about Fault Management in SDNs.

Best regards and much success

Anatol Badach

• Paulo César da Rocha Fonseca, Edjard Souza Mota: A Survey on Fault Management in Software-Defined Networks; IEEE Communications Surveys & Tutorials, Vol. 19, Issue 4, Fourthquarter 2017

https://ieeexplore.ieee.org/document/7959044

• Yinbo Yu , Xing Li et al.: „Fault Management in Software-Defined Networking: A Survey“; IEEE Communications Surveys & Tutorials, Vol. 21, Issue 1, Firstquarter 2019

https://ieeexplore.ieee.org/document/8456508

• Jie Lu, Zhen Zhang, Tao Hu, Peng Yi, Julong Lan: A Survey of Controller Placement Problem in Software-Defined Networking; IEEE Access, Vol. 7, Jan. 2019

https://ieeexplore.ieee.org/document/861844

• Liehuang Zhu, Md Monjurul Karim, Kashif Sharif, Fan Li, Xiaojiang Du, Mohsen Guizani: „SDN Controllers: Benchmarking & Performance Evaluation“; arXiv:1902.04491v1 [cs.NI], Feb. 2019

https://arxiv.org/abs/1902.04491v1

• Abha Kumari, Ashok Singh Sairam: A Survey of Controller Placement Problem in Software Defined Networks; arXiv:1905.04649v1 [cs.NI], May 2019

https://arxiv.org/pdf/1905.04649.pdf

see my paper Article Machines' Fault Detection and Tolerance Using Big Data Management

hi.,

Kindly refer this link:

Article Fault Management in Software-Defined Networking: A Survey

Hello everyone

Thank you so much for the reply of the question asked by me.

Further, I am thinking of integrating SDN and DTN(Opportunistic Networks) together and initially I am thinking on fault management, reliability issues in both. Is it ok can I go ahead any suggestions please let me know.....

Thanks

Sharath