Routing Performance Evaluation of a Multi-Domain Hybrid SDN for Its Implementation in Carrier Grade ISP Networks  
[PERSON]  
1 Department of Electronics and Computer Engineering, Pulchowsk Campus, Tribhuvan University, Kathmandu 19758, Nepal, [EMAIL_ADDRESS] (A.T.); [EMAIL_ADDRESS] (R.G. ); [EMAIL_ADDRESS] (D.K. ); [EMAIL_ADDRESS] (S.P.U. ); srioshitioee.edu.np (S.R.J.) 1  
[PERSON]  
1 Department of Electronics and Computer Engineering, Pulchowsk Campus, Tribhuvan University, Kathmandu 19758, Nepal, [EMAIL_ADDRESS] (A.T.); [EMAIL_ADDRESS] (R.G. ); [EMAIL_ADDRESS] (D.K. ); [EMAIL_ADDRESS] (S.P.U. ); srioshitioee.edu.np (S.R.J.) 1  
[PERSON]  
1 Department of Electronics and Computer Engineering, Pulchowsk Campus, Tribhuvan University, Kathmandu 19758, Nepal, [EMAIL_ADDRESS] (A.T.); [EMAIL_ADDRESS] (R.G. ); [EMAIL_ADDRESS] (D.K. ); [EMAIL_ADDRESS] (S.P.U. ); srioshitioee.edu.np (S.R.J.) 1  
[PERSON]  
1 Department of Electronics and Computer Engineering, Pulchowsk Campus, Tribhuvan University, Kathmandu 19758, Nepal, [EMAIL_ADDRESS] (A.T.); [EMAIL_ADDRESS] (R.G. ); [EMAIL_ADDRESS] (D.K. ); [EMAIL_ADDRESS] (S.P.U. ); srioshitioee.edu.np (S.R.J.) 1  
In SDN, network devices are controlled by an SDN controller and the applications are installed on the top of the controller. When the control and data plane functionalities are segregated, the network switch becomes simply a data plane forwarding device. The control logic is implemented in a logically centralized controller, which runs a network operating system (NOS) that runs on commodity server hardware to provide necessary resources to facilitate the proper control and operation of data plane devices based on a logically centralized, abstract network view [1]. The logical centralization of the control logic makes it flexible and provides error-free policy deployment through high-level programming languages as an application programming interface (API), compared to the low-level device-specific configurations frequently used in legacy networks. The controller provides the global view of the overall network, which simplifies the development of more robust network functions, services and applications. The resulting network is also programmable through software applications running on top of the controller OS, which interact with the underlying data plane devices. The APIs at the controller can automatically react to spurious changes of the network state and keep high-level policies intact [1]. Though SDN implementation in datacenter networks is popular, its proper implementation with the migration of a legacy network to carrier grade ISP (CG-ISP) and telecommunication (Telcos) networks is becoming a central challenge for service providers due to the need for real time migration as well as the higher cost of investment [2; 3]. Additionally, real time implementation of SDN in production networks is the subject of ongoing research. Hybrid SDN is the only solution for the smooth migration of legacy ISP/Telcos networks into SDN [4; 5]. In this paper, an emulated network environment is created in Mininet for hybrid SDN implementation and routing performance evaluation by comparing legacy routing and SDN routing with their interoperability through an experimental analysis using an open network operating system (ONOS)/SDN-IP [6]. The viability of the SDN implementation in ISP/Telcos networks is then evaluated. The major contributions of this paper are as follows. * A multi-domain hybrid SDN environment is created and implemented in the routing between SDN and legacy networking domains. * Routing performance is evaluated, comparing legacy routing and SDN routing using ONOS/SDN-IP. Routing using SDN-IP has a better performance than legacy routing. * This experimental analysis evaluates the viability of SDN implementation in ISPs and Telcos networks. This encourages the service providers to smoothly migrate their legacy networks into SDN. The rest of this paper is organized as follows. Section 2 presents the background and related work in the field of SDN and legacy network integration.