Microservice-Based Framework for Multi-Domain SDN Orchestration

This technical report presents eMSN, a microservice-based framework designed for Software-Defined Networking (SDN) orchestration across multiple domains. Traditional SDN controllers are often monolithic, which limits their scalability and adaptability in distributed environments. The eMSN framework addresses these limitations by enabling controller decomposition, allowing for decentralized orchestration. It introduces lightweight, containerized microservices that communicate via REST APIs and coordinate through a shared ETCD cluster. The primary component, FlowBlocker, collects topology and host information, builds a policy-aware decision table, and manages state without relying on centralized policy resolution. The architecture supports various deployment models, including centralized and fully decentralized options. The report details the functional evaluation of the framework, demonstrating its responsiveness and policy enforcement capabilities. Additionally, it outlines the contributions of the framework, including a reproducible testbed implementation and the potential for future research in decentralized policy enforcement and intelligent orchestration.