OpenFlow

NVIDIA MLNX-GW User Manual for NVIDIA Skyway Appliance v8.2.2200

NVIDIA Onyx supports OpenFlow 1.3. OpenFlow is a network protocol that facilitates direct communication between network systems via Ethernet. Software Defined Networks (SDN) allows a centralist management of network equipment. OpenFlow allows the SDN controller to manage SDN equipment. The OpenFlow protocol allows communication between the OpenFlow controller and OpenFlow agent.

OpenFlow is useful to manage switches and allow applications running on the OpenFlow controller to have access to the switch’s data path and provide functionality such as flow steering, security enhancement, traffic monitoring and more.

The OpenFlow controller communicates with the OpenFlow switch over secured channel using OpenFlow protocol.

An OpenFlow switch contains a flow table which contains flows inserted by the OpenFlow controller. And the OpenFlow switch performs packet lookup and forwarding according to those rules.

OpenFlow switch implementation is based on the hybrid model, allowing the coexistence of an OpenFlow pipeline and a normal pipeline. In this model, a packet is forwarded according to OpenFlow configuration, if such configuration is matched with the packet parameters, otherwise the packet is handled by the normal (regular forwarding/routing) pipeline. NVIDIA Onyx allows configuring regular switch port and port-channel ports to be in hybrid mode (this is relevant to regular switch ports, port-channel switch ports, regular router ports and port-channel router ports).

The OpenFlow specification defines:

“OpenFlow-hybrid switches support both OpenFlow operation and normal Ethernet switching operation, i.e. traditional L2 Ethernet switching, VLAN isolation, L3 routing (IPv4 routing, IPv6 routing...), ACL and QoS processing. Those switches must provide a classification mechanism outside of OpenFlow that routes traffic to either the OpenFlow pipeline or the normal pipeline. For example, a switch may use the VLAN tag or input port of the packet to decide whether to process the packet using one pipeline or the other, or it may direct all packets to the OpenFlow pipeline.”

Utilizing the built-in capabilities of the hybrid switch/router is the main benefit of the hybrid mode. It increases network performance and efficiency – faster processing of new flows as well as lower load on the controllers. The hybrid switch processes non-OpenFlow data through its local management plane and achieve better efficiency and use of resources, compared to the pure OpenFlow switch.

© Copyright 2023, NVIDIA. Last updated on Nov 15, 2023.