in Manager, Capability Abstractions, Flow Programming, Inventory, etc.) GBP Renderers OpenFlow Southbound Interfaces 1.0 1.3 TTP OVSDB NETCONF PCMM/COPS Plugin20C & Protocol Plugins Data Place Elements OpenFlow Enabled Additional Virtual & Devices vSwitches Physical Devices (Virtual Switches, Physical Device Interfaces) Figure 6.2 OpenDayLight. 6 Open Source and Research Activities functionalities. The previously mentioned service function chaining functionality is also in this category. The service abstraction layer enables ODL to support multiple southbound protocols and provide a uniform set of services to other modules. The device discovery service is provided to form the network topology. Finally, we would like to highlight that ODL uses a modeling lan- guage to formally develop and manage various network elements. It uses the yet another next generation (YANG) data modeling language to model network elements, configuration, network states, and SO on. It can also be used to model services, protocols, policies, and tenants. It defines data models in modules SO that data can be imported/exported between them. 6.1.3 OPNFV Open platform for NFV (OPNFV) is an open source project that intends to provide an open source platform for deploying NFV solutions [113]. Its goal is to promote interoperable NFV solutions and to create code for NFV implementations. If each NFV vendor implements its own NFV solution, then the interoperability as an industry will be very challenging. More specifically, the goals of OPNFV can be summarized as follows: Developing an integrated and tested open source platform that can be used to build NFV functionality, accelerating the introduction of new products and services. Including participation of leading end users to validate OPNFV meets the needs of user community. Contributing to and participating in relevant open source projects that will be leveraged in the OPNFV platform; ensure consistency, performance, and interoperability among open source components. Establishing an ecosystem fo