Remember mullets? The unfortunate late-20th-century men's hairstyle was neat and trimmed around the face and long and flowing down the neck. "Business in front, party in the back," was the slogan.

Service provider networks have become mullets.

The parallel occurred to me during a panel at Light Reading's Big Telecom Event. By day, carrier networks primarily carry data traffic for business customers. But at night, Netflix Inc. (Nasdaq: NFLX) rules, said Cengiz Alaettinoglu, CTO for Packet Design.

Figure 1: No Actual Mullets The only mullets on the Big Telecom Event carrier SDN panel were metaphorical.

Data networks for business and video networks for consumers have very different needs, and SDN is needed to manage both customer sets, Alaettinoglu said. "Provisioning one network is a challenge," he said. Now every network is two networks.

A financial customer demands low latency but might be unconcerned about bandwidth. Video customers have different needs. Programmable networks built using SDN make those problems "tractable," he said.

Rob Schrage, senior director, technology services, NTT America Inc. , agreed. SDN allows network operators to specify network, content and service attributes, he said.

But service providers face obstacles implementing SDN. Standards bring both benefits and problems, panelists said.

For an example of benefit, NTT depends on OpenFlow to provide interfaces to simplify controlling network hardware. "There will always be the physical interface," Schrage said.

Likewise, the SDN controller provides a simplified set of southbound APIs to control devices, and northbound APIs to applications. "As long as each vendor provides a southbound hook into a controller, it will get taken care of," Alaettinoglu said. There are now more than 20 SDN controllers available, but those will consolidate soon, and support will not be difficult. (See Who Does What: SDN Controllers.)

But standards take more than two years to develop. "I love standards, but it's too slow to give you the agility you need," Alaettinoglu said.

Abel Tong, director, solutions marketing, Cyan Inc. , also declared his love for standards, and noted he participates in many standards organizations. "If I were to criticize myself and the work I'm doing with them -- we're working on too detailed a level," he said. Standards bodies need to describe services, rather than device-specific protocols.

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Standards also drive commoditization, making it difficult for vendors to differentiate and compete, Tong said.

Schrage disagreed that standards are slow. "I don't view OpenFlow as a hard standard that takes long to ratify. In the software world, it doesn't take two to three years, it takes months," he said.

"For a service provider, I'd rather just have a protocol written. It's easy to adapt to and if it doesn't work I'll switch to another one," he said.

— Mitch Wagner, , West Coast Bureau Chief, Light Reading. Got a tip about SDN or NFV? Send it to [email protected].