In a typical data center, approx. 100k per second is the median flow arrival rate. And worst case estimates are 10M flow arrivals per second. With the great ongoing digital explosion, there are no surprises that these estimates would be revised to much larger values every few months. All these flows have to be processed & setup by the controller(s) & that can potentially become a single point bottleneck in the network.


Thus, the metric that most high-end customers are looking at, is the performance of the SDN controllers. And not so surprisingly, there is no single magic test that can define performance characteristic of such a critical piece of the next gen networks. Following are a few key metrics that customer as well as SDN controller vendors should consider while defining or evaluating the SDN controller performance :

  • How many flows per second, can it handle?
  • How many flows per second, can it handle within acceptable latency?
  • How many SDN-capable switches can it handle within the acceptable latency?
  •  How does it perform with multiple AUXILLARY connections per switch?
  • How does it handle a constantly increasing load versus a burst of flow setup load?
  • How many flows can it store to avoid another level of latency which is associated with flooding the switch
    ports to know the destination?

Calsoft and SDN performance measurement
Calsoft has developed Enhanced Cbench (eCbench) to measure performance of SDN controller. It has following features:

  • Supports OFP 1.0 & 1.3
  • Supports user defined raw packet definition for the embedded packets in packet_in
  • Supports user defined, extensible packet definition (TCP, UDP, etc.) for the embedded packets in
  • Supports AUXILLARY connections Supports user defined number of
    fake switches
  • Supports data rate limit as per user defined configuration
  • Supports multi-threading to be able to load the work queue of controller
  • Supports intuitive & highly configurable INI format based test configuration file
  • Measures latency & throughput of controller in various scenarios

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Contributed by: Nitin Singhvi | Calsoft Inc.