A Deep Dive into the ONOS SDN Controller

Introduction to ONOS

ONOS (Open Network Operating System) is a carrier-grade open source SDN controller. It is a project of the Open Networking Foundation (ONF), and it is designed to be a highly available, scalable, and performant platform for building next-generation networks. ONOS is used by a number of service providers and enterprises to power their networks.

This article will provide a technical deep dive into the ONOS SDN Controller, exploring its architecture, key features, and how it is being used to build the networks of the future.

ONOS Architecture

The ONOS architecture is designed to be highly available, scalable, and performant. It is a distributed architecture that is made up of a number of different components, each of which can be run on a separate server. This allows the controller to be scaled out to meet the needs of even the largest networks.

The ONOS architecture is also highly modular. It is made up of a number of different subsystems, each of which provides a specific function. Some of the most important subsystems in the ONOS architecture include:

The Core: The core is the heart of the ONOS controller. It provides the basic services that are needed by all of the other subsystems.
The Southbound Interface: The southbound interface is responsible for communicating with the network devices. ONOS supports a wide range of southbound protocols, including OpenFlow, NETCONF, and OVSDB.
The Northbound Interface: The northbound interface is responsible for exposing the capabilities of the controller to the applications that run on top of it. ONOS provides a RESTful API that can be used to manage the controller and the network.
The Application Layer: The application layer is where the network applications run. These applications can be used to perform a wide range of tasks, such as network virtualization, security, and traffic engineering.

High Availability

ONOS is designed to be a highly available platform. It achieves this by using a distributed architecture and by replicating all of the important data structures across multiple servers. This means that if one server fails, another server can take over without any interruption in service.

ONOS also uses a number of other techniques to ensure high availability, such as:

Leader election: ONOS uses a leader election algorithm to ensure that there is always a single master instance of the controller.
Data replication: ONOS replicates all of the important data structures across multiple servers.
Failure detection: ONOS has a failure detection mechanism that can quickly detect when a server has failed.

Scalability

ONOS is designed to be a highly scalable platform. It achieves this by using a distributed architecture and by sharding the data across multiple servers. This means that the controller can be scaled out to meet the needs of even the largest networks.

ONOS also uses a number of other techniques to ensure scalability, such as:

Distributed data store: ONOS uses a distributed data store to store all of the important data structures.
Asynchronous communication: ONOS uses asynchronous communication to avoid blocking.
Load balancing: ONOS uses load balancing to distribute the load across multiple servers.

Performance

ONOS is designed to be a high-performance platform. It achieves this by using a number of techniques, such as:

In-memory data store: ONOS uses an in-memory data store to store all of the important data structures.
Asynchronous communication: ONOS uses asynchronous communication to avoid blocking.
Multi-threading: ONOS uses multi-threading to take advantage of multiple CPU cores.

Conclusion

ONOS is a carrier-grade open source SDN controller that is designed to be a highly available, scalable, and performant platform for building next-generation networks. The ONOS architecture is based on a distributed and modular design that allows it to be scaled out to meet the needs of even the largest networks. As SDN continues to gain traction in the networking industry, the importance of the ONOS controller will only continue to grow.