For any switch to be designated as OpenFlow conformant, it must meet strict requirements from the Open Networking Foundation. But conformance testing conveys nothing about real-world performance. A new white paper from Spirent explains the importance of OpenFlow performance testing and describes methodologies companies can use to test on their own.
OpenFlow performance testing is in its infancy. Few open source tools exist for testing OpenFlow performance, though testing features are starting to appear in commercial products. As the complimentary white paper, “OpenFlow Performance Testing,” indicates, there currently is no standard for comparing the performance of OpenFlow products.
Spirent has utilized its extensive experience in testing networking protocols and networking devices to develop a comprehensive framework for testing OpenFlow. The paper covers the salient aspects of that experience and focuses on testing OpenFlow performance in Ethernet switches, which differs from typical switch testing in that it is not entirely focused on packet forwarding performance. In addition, OpenFlow performance testing deals with factors such as how fast a switch can process “flow-mod” messages, and orthogonal packet processing through the OpenFlow pipeline.
The white paper looks at six essential tests for gauging OpenFlow performance of an Ethernet switch:
- Table capacity testing: validates that a flow got installed; determines when a table is full; figures out how many flows are in the full table; and repeats this process for each table under test
- Flow-mod performance: determines how fast a switch’s OpenFlow lookup table can be updated
- Packet in/out performance: measures how fast encapsulated data packets can be sent between the switch and the controller
- Table-miss flow entry performance
- Flow statistics testing: tracks the number of packets and bytes that have matched on each flow, as well as the time since the last packet matched the flow to aid in the removal of inactive flows
- Pipeline processing performance: gauges the ability of an OpenFlow switch to process packets orthogonally
Both builders and users of SDN products need to be able to know that OpenFlow products are performing as desired and to compare performance between products. The tests described in the paper focus on hardware switches, but IT professionals can apply the same methodologies to software switches as well.
To learn more about detailed methodologies for OpenFlow performance testing in Ethernet switches, download the complimentary white paper today. Future white papers will cover controller and complete system testing.