Chapter 4. How does OpenDaylight cooperate with OpenStack?

OpenStack Networking (neutron) supports a plugin model that enables integration with multiple different systems in order to implement networking capabilities for OpenStack.

For the purpose of OpenStack integration, OpenDaylight exposes a single common northbound service, which is implemented by the Neutron Northbound component. The exposed API matches the neutron REST API. This common service allows multiple neutron providers to exist in OpenDaylight. The Red Hat OpenDaylight solution is based on NetVirt as a neutron provider for OpenStack. It is important to highlight that NetVirt consumes the neutron API, rather than replacing or changing it.

The OpenDaylight plugin for OpenStack neutron is called networking-odl, and it is responsible for passing the OpenStack network configuration to the OpenDaylight controller. Communication between OpenStack and OpenDaylight occurs using the public REST APIs. This model simplifies the implementation on the OpenStack side, because it offloads all networking tasks onto OpenDaylight, which diminishes the processing burden for OpenStack.

Figure 4.1. OpenStack and OpenDaylight Architecture

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The OpenDaylight controller uses NetVirt to configure Open vSwitch instances, which use the OpenFlow and OVSDB protocols, and provides the necessary networking environment. This includes Layer 2 networking, IP routing, security groups, and so on. The OpenDaylight controller can maintain the necessary isolation among different tenants.