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Multiple SDN protocols eclipse OpenFlow

An overabundance of SDN protocols are expected to dim OpenFlow's importance and eventually lead to less flexible network controllers for corporate data centers.

OpenFlow has failed to fulfill its promise of becoming the universal protocol within software-defined networking (SDN). As a result, incompatible protocols developed to fill the void are contributing to the uncertainty that's keeping companies away from SDN.

Experts have predicted for several years that OpenFlow had too many weaknesses to become the only protocol that lets an SDN controller tell network switches where to send traffic. Consequently, vendors are using five other protocols to replace OpenFlow.

The use of multiple SDN protocols means controllers, switches and routers will have to support the same technology in order to interoperate. "They [enterprises] should choose their SDN controller carefully, because it's unlikely one controller will ever be able to communicate with any switch or router," said Andre Kindness, analyst at Forrester Research Inc., based in Cambridge, Mass.

Proponents claimed OpenFlow, managed by the Open Networking Foundation, would ease interoperability. However, it failed to gain traction because many switch makers decided the cost of using the SDN protocol outweighed the benefits, according to Doug Marschke, CTO at professional services company SDN Essentials in Newark, Del. Vendors that manufacture chips used in switches also found OpenFlow too cumbersome.

OpenFlow weakness spawns rivals

The SDN protocol's difficulties created an opening for organizations to use other protocols in approaches that compete with OpenFlow. Rival protocols include Border Gateway Protocol (BGP), NETCONF, Extensible Messaging and Presence Protocol (XMPP), Open vSwitch Database Management Protocol (OVSDB) and MPLS Transport Profile (MPLS-TP).

Which, if any, of the half dozen protocols will dominate the SDN market is anyone's guess. These kinds of uncertainties have prevented most corporations, other than service providers and financial institutions, from using SDN in their data centers. "Infrastructure and operations professionals aren't willing to place a bet that could get them fired," Kindness said.

Infrastructure and operations professionals aren't willing to place a bet that could get them fired.
Andre Kindnessanalyst, Forrester Research

A technology shakeout will eventually occur. In the meantime, Joe Skorupa, analyst at Gartner Inc., based in Stamford, Conn., expects to see a lot more product innovation before the network architecture becomes mainstream.  

"As competition heats up and companies are increasingly forced to compete for the business, we will see new, interesting and previously unaccepted business models coming into play," Skorupa said. "We're seeing lots of opportunity for market disruption."

Talk to multiple vendors

To stay abreast of technology changes, companies that want to test SDN should talk to their current vendor and at least two others -- an established vendor and a startup, said Skorupa. "You will learn what is possible by looking at the alternative providers."

Companies that talk to several vendors will have the opportunity to compare products, while also putting the incumbent on notice that it has to earn new business. "It's not loyalty that gets rewarded; it's the potential risk that someone might lose an account," Skorupa said.

Next Steps

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