| dc.description.abstracteng | Network softwarization changes the way how should networks be managed. Introducing Software-defined Networking in the last decade helps network administrators focus on network management and write optimized applications that control network behavior. Network administrators communicate with a network controller through an interface named northbound interface. This interface and any abstract build on it should be designed to enforce the ease of the network management to align with the primary purpose of Software-defined Networking. The performance of these abstractions is affected by the data organization and software libraries used to deliver northbound interface services to end users.
We start with Gavel, an SDN controller that at its heart facilitates a plain data representation based on a graph database. In Software-defined Networking, high-level abstractions typically offer a useful means to avoids writing network applications and policies on lower levels. However, abstractions are typically developed for a specific use case, which in turn results in an abundance of existing abstractions for different networking tasks. As a consequence orchestrating these abstractions to implement a standard network policy becomes an arduous task. To address this challenge, plain data representations of the network and its control infrastructure have been proposed recently, which offer programmable ad-hoc abstractions to administrators. However, these frameworks suffer from quite complex programming requirements and impractical performance in terms of latency, as they are based on relational database engines.
By exploiting the native graph support of the database engine, Gavel significantly eases application and policy writing. Additionally, we show by experimental evaluation of several typical applications on multiple different topologies that Gavel offers significant performance improvements over state-of-the-art solutions.
In the second part of the thesis, we present Busoni, a framework that we build on Gavel to provide needed libraries to manage policies on top of Segment Routing. Segment Routing is a promising solution to support services like Traffic Engineering, Service Function Chaining and Virtual Private Networks. It is a source routing based networking architecture that provides an opportunity to include a list of instructions called segments in the packet headers. The segments may allow the inclusion of detours for responding to Traffic Engineering needs or Service Function Chains implementations. Even though there is an increasing interest in enhancing and adopting Segment Routing, the administrators are still burdened with the task of manually write and maintain the segment lists. Such type of management presents several challenges ranging from error-prone configurations to increased response time for network updates.
To address these challenges, we propose Busoni that automates and simplifies the process of segments lists management. Additionally, we also provide programming tools to compose and manage Segment Routing policies that operate efficiently even under multi-tenancy environments. Using different use cases we show the programming capabilities offered by our framework. With experimental evaluation, we demonstrate the scalability of our platform and the improvements achieved in response time for dynamic network events.
This thesis investigates the role of efficient data management and policy composition in Software-defined Networking frameworks. It sheds light on the importance of data representation and how it affects the performance of network application. It also presents one of the first frameworks that manage network policies in the new network technology (i.e, Segment Routing). The work presented in this thesis has been implemented, evaluated, and published as an extension to the state-of-the-art knowledge in the related field. | de |