Open-source software has played a significant role in networking for over two decades, but has emerged as particularly important to the unprecedented industry transformation underway catalyzed by SDN and NFV. Open networking requires open source, and the industry has responded with a rapidly growing set of open-source networking and orchestration projects.
What is open source? Like so many networking terms (e.g., services, applications, virtualization, and even network, among many others), and tens of millions of projects, open source has taken on a number of meanings by various organizations. Our definition presents open source in the context of networking, which is characterized by the following attributes:
- A distribution model for software (and increasingly, hardware as well)
- Inclusive, with low barriers for a broad range of contributors to participate
- Deliverables are readily accessible, and consumers are free to distribute the code
- Sustainability, propelled by strong community support
For many, open source is synonymous with ‘free’, including no cost, and unrestricted access to source code. While most open-source networking projects do not entail a license fee, adopters of open source incur significant cost in integrating, testing, adapting, and maintaining open source code for real-world solutions. Adopters are subject to the terms of the many different open source license agreements governing the use of the code. Contributors are also subject to license agreements as well, typically imposed by the project.
Other misconceptions are summarized in Table 1 below
|“Open source is Free”||Fact: Significant cost is required to adopt, test and maintain open source (like any software!)|
|“Open source spells the end for vendors”||Fact: Open source presents a number of opportunities for vendors to capitalize upon their core competencies|
|“Open source is created by individuals who are passionate about the code”||Fact: Many open-source networking projects are backed by corporate entities that fund the developers contributing to the project|
|“Open source is more vulnerable than proprietary software”||Fact: Open source is usually more secure than proprietary software because of the extensive vetting by the developers and public visibility of every line of code|
|“Open source is not mission critical”||Fact: Open source is integral to virtually all large-scale software systems and popular projects are more tested and scrutinized than proprietary software.|
|“Open source replaces proprietary software.”||Fact: While open source replaces some proprietary software, it enables software developers to focus on proprietary, high-value software. Virtually all proprietary platforms today adopt significant open source components.|
Table I Open Source Myths (and realities)
Open Source Taxonomy
As the telecommunications and cable industry increasingly relies upon open source for networking, a number of different projects have been established to address a wide range of requirements. In Figure 1, we present an open-source networking project taxonomy based on the desired outcomes, including some well-known examples.
Platform projects are largely scale open source frameworks that provide extensive functionality and integrate with a broad range of external components (see below). Examples include the Open Network Automation Platform (ONAP) orchestration and automation platform, OpenStack cloud operating environment, and OpenDaylight SDN controller framework. Platforms are typically large projects with dozens of members, and are intended for large-scale deployment.
Component projects provide more targeted functionality and are typically integrated into platforms to implement a broad solution. Examples include:
- OpenvSwitch (OvS) virtual switch
- Fast Data IO (FD.io), which enhances the data plane switching performance
- OpenSwitch embedded white box operating system
- Open Network Install Environment (ONIE), boot loader for embedded network operating systems
- Open Networking Operating System (ONOS), an embedded SDN controller adopted by the Central Office Re-architected as a Data Center (CORD) initiative.