Understanding the QFabric System Data Plane
The data plane in the QFabric system transfers application traffic between QFabric system components rapidly and efficiently. This topic covers:
Data Plane Components
Data traffic within a QFabric system is carried across a redundant, high-performance, and scalable data plane. To maintain high availability, the QFabric system data plane is separated physically from the QFabric system control plane and uses a different network. Figure 1 shows an example diagram of the QFabric system data plane network.
The QFabric system data plane includes the following high-speed data connections and elements:
10-Gigabit Ethernet or 2-Gbps, 4-Gbps, or 8-Gbps Fibre Channel connections between QFabric system endpoints (such as servers or storage devices) and the Node devices.
40-Gbps quad, small form-factor pluggable plus (QSFP+) connections between the Node devices and the Interconnect devices.
10-Gigabit Ethernet connections between external networks and the Node devices contained in the network Node group.
A fabric control protocol, used to distribute route information to all devices connected to the QFabric system data plane.
QFabric System Fabric
Unlike traditional data centers that employ a multi-tiered hierarchy of switches, a QFabric system contains a single tier of Node devices connected to one another across a backplane of Interconnect devices. The QFabric system fabric is a distributed, multistage network that consists of a fabric queuing and scheduling system implemented in the Node devices, and a distributed cross-connect system implemented in the Interconnect devices. The cross-connect system for the QFX3008-I Interconnect device is shown as an example in Figure 2.
The design of the cross-connect system provides multistage Clos switching, which results in nonblocking paths for data traffic and any-to-any connectivity for the Node devices. Because all Node devices are connected through the Interconnect device, the QFabric system offers very low port-to-port latencies. In addition, dynamic load balancing and low-latency packet flows provide for scaling the port count and bandwidth capacity of a QFabric system.