The data center, or DC, is a physical infrastructure that companies typically use to house computing, networking, and storage resources as a unified computational platform.
A segment of a network architecture that is responsible for transferring user traffic.
In contrast with the centralized control plane design, decentralized control plane assumes the control plane and data plane are colocated in a data center.
Disaster recovery (DR) is the set of processes and procedures that enable system repair after a critical error or a catastrophic event, such as hardware failures, natural disasters cyber attacks and so on. Disaster recover typically includes planning an off-site back up facility, data replication schedule, and other actions and infrastructure components that allow quickly restore business-critical functions of the affected organization.
A Distributed Virtual Router (DVR) provides highly-available multi-host routing to Neutron network topologies. A DVR spreads the L3 agent functionality to compute nodes, so that the internal virtual machine traffic does not flow to the controller node (East-West Routing). Such network topology assists with network load distribution, as well as helps to eliminate a single point of failure.
Neutron DVR also implements the floating IP namespace (one new namespace for all the Floating IPs per external network) on every compute node where virtual machines are located. In this case, the virtual machines with floating IPs can forward the traffic to the external network without reaching the controller node (North-South Routing).
Note
The term East-West defines network traffic between virtual machines in different subnets. And the term North-South defines network traffic between a virtual machine and the Public network.
Neutron DVR provides the legacy SNAT (Source Network Address Translation) functionality for the default SNAT for all private virtual machines. SNAT service is not distributed, it is centralized and the service node hosts the service.