OpenDayLight (ODL) Controller Review: Cloud & Telco SDN 2025
OpenDayLight (ODL) stands as the most pervasive open-source SDN controller platform, with a score of 84.5% in our comprehensive evaluation and the largest community support in the market. Designed from the outset as a foundation for commercial solutions, ODL excels in cloud integration scenarios, particularly with OpenStack, Kubernetes, OPNFV, and ONAP—making it the de facto choice for telco cloud and NFV environments.
This is part of our comprehensive SDN Controller Comparison Guide, where we evaluate 6 leading open-source controllers across 13 technical criteria.
OpenDayLight at a Glance
| Attribute | Details |
|---|---|
| Overall Score | 84.5% (Ranked #2) |
| Best For | Cloud integration, SD-LAN, telco NFV, data centers |
| Architecture | Modular, three-layer with OSGi |
| Programming Language | Java |
| Primary Protocols | OpenFlow, P4, NETCONF, SNMP, BGP, RESTCONF, PCEP |
| Clustering | Native (AKKA datastore) |
| Community | Linux Foundation Networking (largest community) |
| Key Differentiator | Broadest ecosystem integration (OpenStack, K8s, ONAP) |
| Deployment Complexity | High (feature-rich = more complexity) |
| License | Eclipse Public License 2.0 |
What OpenDayLight Does Best:
- Largest open-source SDN community and ecosystem
- Native integration with cloud platforms and orchestrators
- Most extensive plugin and project ecosystem
- Model-driven architecture with YANG support
- Production-proven in telco NFV deployments
Architecture Deep Dive
ODL consists of 3 layers:
Modularity and Extensibility
Built-in mechanisms provided by ODL simplify the connection of code modules. The controller takes advantage of OSGi containers for loading bundles at runtime, allowing a very flexible approach to adding functionality.
Scalability
ODL uses a model-based approach, which implies a global, in-memory view of the network is required to perform logic calculations. ODL’s latest release further advances the platform’s scalability and robustness, with new capabilities supporting multi-site deployments for geographic reach, application performance and fault tolerance.
Telemetry
At a project level, ODL has limited telemetry related functionality. With the latest development release, there are moves toward providing northbound telemetry feeds, but they are in early design and not likely to be ready for production in the short term.
Resilience and Fault Tolerance
ODL fault tolerance mechanism is similar to ONOS, with an odd number of SDN controllers required to provide fault tolerance in the system. In the event of master node failure, a new leader would be selected to take the control of the network. The mechanism of choosing a leader is slightly different in these controllers – while ONOS focuses on eventually consistent, ODL focuses on high availability.
Programming Language
From a language perspective, ODL is written in Java.
Community
ODL is the second of the SDN controllers under the Linux Foundation Networking umbrella. This project has the largest community support of all open source SDN controllers in the market, with several big-name companies actively involved with development.
Conclusion
OpenDayLight is the most pervasive open-source SDN controller with extensive northbound and southbound APIs. In addition to resiliency and scalability, the modular architecture of ODL makes it a suitable choice for different use-cases. This is why OpenDayLight has been integrated into other open-source SDN/NFV orchestration and management solutions such as OpenStack, Kubernetes, OPNFV and ONAP which are very popular platforms in telco environments.
Next, we will be evaluating OpenKilda.
