# Practical Implementation of a Blockchain-Enabled SDN for Large-Scale Infrastructure Networks
## 7 Conclusions  
This work focused on and validated the possibility of integrating and using blockchain nodes in SDN controllers. The connection and communication between the blockchain nodes outside of their organization's networks were also addressed and validated. The means of using Mininet as an SDN platform and the provided POX controller together with the Ethereum blockchain implementation in Geth were presented. The potential for augmenting the POX SDN controller to facilitate the integration of a blockchain node and the execution of said node on the controller has been demonstrated. The paper also proposes an architecture model for integrating and using blockchain technology in the SDN networks, it presents the benefits and provides use cases and ideas that can be applied (independently or combined) in such a combination of integrated technologies. The research focused on the collaboration between ISPs aimed at minimizing the impact of running and maintaining blockchain nodes over the resources of a single ISP. For this purpose, an original concept of organizing individual ISPs in a federation--virtual ISPs (vISPs)--was provided to allow the interconnection of heterogeneous ISPs. Using the proposed approach, resources can be shared for the benefit of the entire federation, and regulations and standardization can be implemented in order to obtain an improved functionality and experience of using the integrated technologies. By integrating the aforementioned components, a framework in the form of proof of concept was created, to facilitate further developments and improvements in the area of SDNs and blockchain integration and for large-scale network infrastructures. As future work, we plan to investigate how the blockchain nodes integrated into the federation's SDN controllers can be properly isolated from other blockchain nodes that may be trying to connect and communicate over the federation's blockchain network. In this way, the federation's blockchain traffic will be fully isolated, and the nodes will exclusively be tasked with managing the internal intended traffic and data. Another key point for our future work will be the development of smart contracts to provide extended functionality. Deriving from this, we plan to research how smart contracts will affect the SDN controller and how we can correlate the smart contract complexity with increased demand in terms of resources regarding the controller. In this way, we would have a better perspective on how much the load on the SDN controller would increase by adding additional functionality, and we would be in a better position to investigate the right balance for a controller between handling blockchain tasks and the usual SDN tasks. Furthermore, the proposed solution will investigate how the proposed integration scales with increasing numbers of nodes and network traffic to ensure efficient communication and transaction processing in larger networks. To enhance overall network performance and efficiency, optimization techniques will be studied to reduce communication delays and packet exchange overhead. Furthermore, the experimental part will be extended to trials in real-world large-scale networking environments to validate the effectiveness and practicality of blockchain integration in SDN controllers. Although not an objective of our current paper, we also consider the need to evaluate the energy efficiency problem of blockchain-integrated SDN controllers and to provide energy-efficient mechanisms to minimize resource consumption while maintaining network performance at the ISP federation level. As a further step in the integration of these technologies, AI holds immense potential for addressing various challenges. Using Predictive Network Analytics to analyze historical data and real-time network traffic patterns, SDNs could dynamically allocate bandwidth based on changing network conditions and QoS requirements. Furthermore, AI-powered agents can automate the negotiation and enforcement of SLAs between service providers and customers.