Neutron, historically known as Quantum, is the OpenStack project focused on delivering networking as a service. As the Juno development cycle ramps up, now is a good time to review some of the key changes we saw in Neutron during this exciting cycle and have a look at what is coming up in the next upstream major release which is set to debut in October.

Neutron or Nova Network?

The original OpenStack Compute network implementation, also known as Nova Network, assumed a basic model of performing all isolation through Linux VLANs and iptables. These are typically sufficient for small and simple networks, but larger customers are likely to have more sophisticated network requirements. Neutron introduces the concept of a plug-in, which is a back-end implementation of the OpenStack Networking API. A plug-in can use a variety of technologies to implement the logical API requests and offer a rich set of network topologies, including network overlays with protocols like GRE or VXLAN, and network services such as load balancing, virtual private networks or firewalls that plug into OpenStack tenant networks. Neutron also enables third parties to write plug-ins that introduce advanced network capabilities, such as the ability to leverage capabilities from the physical data center network fabric, or use software-defined networking (SDN) approaches with protocols like OpenFlow. One of the main Juno efforts is a plan to enable easier Nova Network to Neutron migration for users that would like to upgrade their networking model for the OpenStack cloud.

Performance Enhancements and Stability

The OpenStack Networking community is actively working on several enhancements to make Neutron a more stable and mature codebase. Among the different enhancements, recent changes to the security-group implementation should result in significant improvement and better scalability of this popular feature. To recall, security groups allows administrators and tenants the ability to specify the type of traffic and direction (ingress/egress) that is allowed to pass through a Neutron port, effectively creating an instance-level firewall filter. You can read this great post by Miguel Angel Ajo, a Red Hat employee who led this effort in the Neutron community, to learn more about the changes.

In addition, there are continuous efforts to improve the upstream testing framework, and to create a better separation between unit tests and functional tests, as well as better testing strategy and coverage for API changes.

Today’s datacenter networks contain more devices than ever before; servers, switches, routers, storage systems, dedicated network equipment and security appliances – many of which are further divided into virtual machines and virtual networks. Traditional network management techniques generally fall short of providing a truly scalable, automated approach to managing these next-generation networks. Users expect more control and flexibility with quicker provisioning and monitoring.

OpenStack Networking (Neutron) is a pluggable, scalable and API-driven system for managing networks and IP addresses. Like other aspects of the cloud operating system, it can be used by administrators and users to increase the value of existing datacenter infrastructure. Neutron prevents the network from being the bottleneck or limiting factor in a cloud deployment and gives users real self service over their network configurations.
Starting in the Folsom release, OpenStack Networking, then called Quantum, became a core and supported part of the OpenStack platform, and is considered to be one of the most exicting projects – with great innovation around network virtualization and software-defined networking (SDN). The general availability of Icehouse, the ninth release of OpenStack, is just around the corner, so I would like to highlight some of the key features and enhancements made by the contributors in the community to Neutron.