CHICAGO -- Light Reading's Big Telecom Event 2014 -- SDN in the transport layer is challenging but inevitable because it will give network operators a way to make their transport networks programmable and application-aware, according to an Optical Internetworking Forum workshop here today.
SDN's appeal to operators is its ability to control the behavior of the applications on their network without being beholden to vendors, said Coriant 's Jonathan Sadler, also the Optical Internetworking Forum (OIF) 's Technical Committee vice chair. That's the biggest difference from other control systems they've employed in the past, he said.
In addition, SDN offers network operators the ability to reduce provisioning times and simplify their networks to reduce costs, said Vishnu Shukla, OIF president and principal technologist at Verizon Communications Inc. (NYSE: VZ).
The OIF has developed a model that meets carrier SDN requirements, Shukla said, but it still needs to go through the demonstration and testing phase in a carrier environment. The first stage will be to come up with use cases that address specific SDN features, such as more rapid provisioning and network simplification. After that, there will still need to be vendor-developed operational tools for network operators to use.
Shukla also pointed to the joint efforts of the OIF and the Open Networking Foundation to do a prototype demonstration of cloud bursting over optical networks which will be publicly run in the fall of 2014. Carriers will have the opportunity to view the demos and also begin to look at the way SDN enables them to create horizontal slices of their networks to simplify the service provisioning process.
Speaking here ahead of BTE, Sadler walked attendees through the history of control plane technologies from the likes of AT&T Inc. (NYSE: T) and Vodafone Group plc (NYSE: VOD). Even the ones that succeeded in reducing costs and speeding service delivery put the operators under the thumb of their vendor partners, he explained. (See ONF, OIF Deep-Dive Into NFV, SDN.)
SDN is different, he said, because it's a carrier-led technology that makes the network programmable, bringing in extra capacity when needed for certain applications and events. SDN improves transport control for network operators and lets them control the behavior of network apps.
"The control plane is really about delivering automation, and SDN is about new behaviors," Sadler said. "You need a way to allow for programming to be done in an SDN environment."
Sadler broke that programmability down into the data plane, which enables new behaviors, app awareness, traffic classification, and switching to deal with failures; and the control plane. "The data plane is now doing the restoration that the control plane used to do," he said. "By having programmability in the data plane, you can make the functions happen quickly."
Programmability becomes essential because it allows the network to think in "what-if" queries -- what is the latency of connecting these two data centers together? Not necessarily doing it, he said, but investigating the possibility to figure out the best route. As such, network operators can assess the behaviors of specific network apps based on an understanding of network congestion, latency, and other factors that would otherwise affect their performance.
"The network app comes in by looking at the service request and deciding what's the best option," Sadler said. "SDN really enables that. With the introduction of open interfaces and programmability, the carriers can get the behaviors they want."
— Sarah Reedy, Senior Editor, and Carol Wilson, Editor-at-Large Light Reading