NEW YORK — Ethernet & SDN Expo — Networks need to be as flexible and on-demand as computing power and storage are today, Ciena CTO Steve Alexander told the Interop keynote crowd here Wednesday, and that will mean a major transformation through software-defined networking (SDN).

Calling SDN "under-hyped," Alexander said the public network must become more dynamic, more flexible, and more real-time, and that will require a major change in how networks are built. Today's networks expand by adding more boxes, but that model won't meet the scale required for future networks, he said.

While coherent optics have allowed the telecom industry to deliver massive amounts of bandwidth, that bandwidth today isn't available where and when it's needed, the Ciena Corp. (NYSE: CIEN) CTO said, and that limits its usefulness.

Alexander described a network of multi-function boxes -- but not "God" boxes, he cautioned -- that are virtualized machines living in a content center, not a Central Office or a datacenter, that can connect consumers to their content/applications via well-defined open interfaces. Such a network would have the ability to treat network traffic depending on its requirements while protecting itself from being overloaded or congested.

Openness will be a major requirement of the next generation of networks, Alexander said, admitting that there still isn't a single view of what "open" will mean, however. (See Ciena's Alexander: The Future's Open.)

He cautioned that industry inertia, and the "loud voices" who fight change and protect legacy approaches could threaten the rollout of SDN and the ability to keep networks truly open. But Alexander closed by predicting that those involved in this change today will one day look back in amazement at how truly transformational SDN became.

— Carol Wilson, Editor-at-Large, Light Reading