It’s fair to say there was a fair amount of skepticism back in early 2013 when the OpenDaylight Project was announced. Why, some wondered, was there a need for a vendor-supported project – albeit under the auspices of the Linux Foundation – to foster open standards around Software Defined Networking (SDN) when the user-driven Open Network Foundation had been plugging away at SDN open standards for more than a year?
Almost exactly on the one-year anniversary of OpenDaylight’s debut announcement, Network World’s Jim Duffy was still looking for monsters under the bed. “[Open]Daylight is defensively strategic to those who seek to marginalize the impact of SDNs in general, and of OpenFlow in particular,” he wrote this past April. In his view, the project was an effort by network hardware vendors led by Cisco and IBM “to stave off OpenFlow's commoditization of network hardware by neutralizing OpenFlow itself.”
Others have been more open to the OpenDaylight effort. Eric Knorr of InfoWorld, for example, said “Rather than hammer out new standards, the project aims to produce an extensible, open source, virtual networking platform atop such existing standards as OpenFlow, which provides a universal interface through which either virtual or physical switches can be controlled via software.”
In a recent proposal calling for a discussion of "integrated hybrid OpenFlow" at an upcoming OpenDaylight Developer Forum, HP noted that OpenFlow can come in two versions of switches: OpenFlow-only and OpenFlow-hybrid.
As HP points out, OpenFlow-hybrid supports both OpenFlow and traditional Ethernet switching.
“The common approach to enterprise SDN assumes a 100 percent pure SDN-controlled solution from the ground-up,” notes the HP proposal. “This approach is expensive in terms of actual cost of new switches and in terms of downtime of the network. By providing a controller that can gradually migrate to an SDN solution, the hybrid approach enables customers to start seeing the value of having an SDN controller without requiring them to make a huge leap in replacing their existing network.”
ONF itself notes HP, “does not plan or intend to incorporate details of legacy protocols in OpenFlow” and has determined that industry can address the issues related to a hybrid switch. HP also notes that Brocade “has been shipping products supporting hybrid OpenFlow for over a year” and that both Red Hat and Juniper have advocated in favor of hybrid OpenFlow.
Brocade’s explanation: “With hybrid port mode, OpenFlow is able to integrate and run on the same physical infrastructure as traditional routing and switching. This unique capability provides a pragmatic path to SDN by enabling network operators to maximize the value of their network, giving them the programmatic control offered by SDN for specific flows while the remaining traffic is routed as before, and scaling up the OpenFlow deployment as network demands change.”
Rather than sinister intentions, it may well be that vendors with one foot in the OpenFlow camp and the other in the OpenDaylight camp, may be speeding up and smoothing the on-ramp to SDN.