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OpenFlow for SDN – still relevant in 2014?

January 10, 2014 1 comment

Metaphor for OpenFlow

Metaphor for OpenFlow

When I read the prediction “OpenFlow is dead by 2014” it got me thinking…  What is it about OpenFlow that inflated expectations and drove things to a fever pitch only to end up in a “trough of disappointment” (to borrow overused analyst terminology) in 2014?  If Software Defined Networking (SDN) is a way to program network operations to serve a business need and involves separating the data plane in the hardware switches from a centralized control plane residing outside the switch, then OpenFlow is a forwarding protocol for SDN.  Once the control plane decides how to forward packets, OpenFlow enables the programing of switches to actually make this happen.  Use-cases for OpenFlow are compelling:

  • Google talked about how they improved WAN utilization from 30-40% which was the norm across the industry to a staggering ~100% using OpenFlow and home-grown switches.  These switches were build by Google using merchant silicon and open source routing stacks for BGP and IS-IS
  •  IPv6 address tracking could be handled by an OpenFlow v1.2 controller and OpenFlow 1.2 enabled switches
  • Data centers can reduce CAPEX by not buying hardware based network taps and instead using OpenFlow to program the functional equivalent of a network tap on a OpenFlow enabled layer 2 switch
  • OpenFlow controllers and OpenFlow enabled switches can help data-centers migrate from old firewalls to new ones in a seamless manner.

So what changed to bring on the naysayers?  All of the above still holds true.  While HP, Dell, Brocade, Arista Networks, Fujitsu, NEC, Big Switch Networks and others embraced OpenFlow, holdouts like Cisco & Juniper supported it grudgingly if at all.   Seeing switch upstart Arista Networks eroding Cisco revenue from Top of Rack (ToR)  switches, Cisco released the Nexus 3100 as one of its few switches to support OpenFlow 1.0 and even VMware NSX.  Juniper de-emphasized work on the OpenDayLight project and OpenFlow and decided to reinvent SDN by acquiring Contrail leading to disastrous results.  Despite all this, those who believe in OpenFlow and are against vendor lock-in march on:  OpenFlow is being evaluated by CenturyLink (3rd largest telecom provider in the USA) and by Verizon, deployed by providers like Sakura Internet, Rackspace, NTT Communications. SDN start-up Pica8 is promoting OpenFlow and switch programmability by offering white box switches, an open-source routing stack, the Ryu OpenFlow controller and an Open vSwitch (OVS) implementation.  Pica8 has won prominent customers like NTT and Baidu with this approach.  Storage start-up Coho Data offers a storage solution that converges networking and storage using OpenFlow & SDN.  If OpenFlow were a sentient being and could speak it would paraphrase Mark Twain and proclaim: “The reports of my death have been greatly exaggerated!”

Categories: NFV, SDN Tags: , ,