Software-Defined Overlay Networking for the Deployment of Distributed Applications at the Edge

Abstract

Today, most applications are distributed to manage the growing volume of data and processes. Simultaneously, the need for low latency, bandwidth efficiency, and privacy has driven the deployment of distributed applications to the network edge. However, the edge poses unique challenges, including widely distributed, heterogeneous, uncontrolled, and untrusted environments.

Accordingly, this monographic thesis presents contributions to simplify the development and deployment of distributed applications at the network edge.

The first contribution addresses the challenges of restricted connectivity in edge networks and the risk of edge device communication in untrusted networks to eavesdropping or forgery. Therefore, this contribution presents an approach for the efficient and secure linking of edge devices. Hence, this thesis introduces a new protocol that efficiently overcomes these connectivity restrictions and simultaneously establishes secure communication channels.

The second contribution simplifies the integration of dynamic overlay networks into edge applications. Previous work often restricts the application design or makes strong assumptions about the underlying network infrastructure. Therefore, this thesis introduces a new application programming interface for overlay network integration into edge applications. The approach establishes an IP overlay that can be adapted by any IP-based application without modification. Overlay services like routing, forwarding, quality of service, or security are dynamically defined and transparently applied to selected application communications. Such overlay services help applications in maximizing edge resource usage.

The third contribution simplifies the deployment of edge applications. Lack of central control, restricted reachability, and heterogeneous edge devices complicate deployment in edge environments. The approach brings capabilities known from software-defined networking, such as centralized network view and control, a common interface for edge device configuration, network configuration based on high-level functional requirements, and a closed-loop mechanism identifying and reverting unintended network changes to the edge.

All contributions have been combined into a fully functional open-source middleware, which was also evaluated in real-world experiments to demonstrate their seamless integration and functional characteristics.