Segment Routing is a source routing based 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 Chaining implementations. Even though there is an increasing interest towards 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. In this paper, we present a Segment Routing management framework named Busoni, which 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.

In software-defined networking (SDN), high-level abstractions typically offer a useful means to avoid 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 common 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. In this paper, we address these shortcomings by introducing Gavel, an SDN controller that at its heart facilitates a plain data representation based on a graph database. 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 the state-of-the-art solutions.

SDN (Software-Defined Networking) promises easier management of complex networks. In abiding by this promise northbound APIs play a major role, as they provide abstractions to ease the process of writing network applications. As more and more of such abstractions emerge, one challenging task is to orchestrate different policies that originate from different abstractions. In an effort to provide automation for this process, recent research has suggested to replace the application-specific abstractions by a primitive, SQL-based data representation of the entire network control infrastructure. This representation can then be transformed into higher-level abstractions. However, the use of relational databases results in performance inferior to existing controllers and still requires complex application writing. To address these issues, in this work we introduce Gavel, a graph database based controller which exploits the natural graph structure of computer networks. Based on results obtained from a prototype implementation, we show that Gavel not only simplifies application writing, but at the same time offers a significantly better performance than existing schemes.