SDN-Based IP and Layer 2 Services with an Open Networking Operating System in the GÉANT Service Provider Network
Pier Luigi Ventre, Stefano Salsano, Matteo Gerola, Elio Salvadori, Mian Usman, Sebastiano Buscaglione, Luca Prete, Jonathan Hart, William J. Snow · IEEE Communications Magazine · 2017
The migration of service providers' wide area networks toward SDN is a challenging task. In this article, we consider the critical requirements of GÉANT, the 500 Gb/s pan-European provider interconnecting 38 national research and educational networks, for a total of 50 million users. A long-term evolution path toward the softwarization of GÉANT is discussed, consisting of four steps to be realized in future years, from providing SDN-based connectivity, to the so-called software defined infrastructure (SDI). As a first step, the softwarization of some basic services currently offered by GÉANT is considered: GÉANT IP, GÉANT plus, and GÉANT Open. This article reports the concrete experience in the SDN-based design and implementation of these services, which have been called L3-SDX and L2-SDX. Both use cases have been addressed with the use of the open source Open Network Operating System (ONOS®). The L3-SDX service has been developed on top of an existing ONOS application, called SDN-IP. SDN-IP allows interconnections between SDN and legacy networks through BGP. The L2-SDX service has been realized as a new ONOS application. Both services are currently deployed on the GÉANT Testbed Service, a continental facility offering geographical virtual testbeds to the research community. The article reports the experience gained from this experimental deployment and discusses the benefits for a service provider like GÉANT.