How software-defined networking layers work with HCI
The networking component has often been overlooked, because early hyper-converged infrastructure (HCI) systems failed to deliver software-defined networking (SDN) in a meaningful way. This has been steadily changing, as #SDN technologies have improved and become better adapted to HCI scenarios. For example, @BigCloud Fabric (BCF), an SDN system offered by @Big Switch Networks, can now be used in HCI services from @Nutanix, @VMware, @Dell EMC and @Red Hat. Other SDN products, including @VMwareNSX and @Cisco Application Centric Infrastructure, are moving just as aggressively into HCI territory. An SDN product such as BCF can use commodity switches from Dell, Hewlett Packard Enterprise and other vendors, while providing a centralized control interface that supports automation and programmability. This allows it to route traffic in a way that best utilizes resources, while accommodating changing workloads. Like HCI in general, SDN takes a software-centric approach to networking that can be fully integrated into the HCI environment. A typical system is divided into three software-defined networking layers: a data plane that physically moves the network packets from node to node; a control plane that abstracts the physical resources in the data plane; and an application plane that controls network behavior via the control plane. Software-defined networking separates the control, data and application planes, making SDN easy to integrate with HCI. The SDN data plane The data plane, also known as the forwarding plane, is made up of physical devices, such as switches and routers. The devices forward the network packets from one node to the next along the defined data path. Unlike a traditional network infrastructure, the SDN does not rely on the control mechanisms built into a device’s firmware, but instead uses the control plane to manage how traffic flows through each device. The software-defined networking layers of data plane, control plane and application plane work together to deliver an SDN platform that can be integrated into an HCI system, along with other software-defined components. SDN’s inherent programmability makes it possible to automate networking operations and support fluctuating workloads, while providing the flexibility necessary to scale components and support different HCI configurations. The SDN control plane Like HCI in general, SDN takes a software-centric approach to networking that can be fully integrated into the HCI environment. The first of the software-defined networking layers, the control plane, abstracts the physical network and specifies how packets should flow through the data plane. The control plane is completely decoupled, or disaggregated, from the data plane, providing a logical, independent interface to the physical resources.