SDN starts to fulfill its network optimisation promise

Infinera, Brocade and ESnet demonstrate the use of software-defined networking to provision and optimise traffic across several networking layers.

Infinera, Brocade and network operator ESnet are claiming a first in demonstrating software-defined networking (SDN) performing network provisioning and optimisation using platforms from more than one vendor.

Mike Capuano, Infinera

The latest collaboration is one of several involving optical vendors that are working to extend SDN to the WAN. ADVA Optical Networking and IBM are working to use SDN to connect data centres, while Ciena and partners have created a test bed to develop SDN technology for the WAN.

The latest lab-based demonstration uses ESnet's circuit reservation platform that requests network resources via an SDN controller. ESnet, the US Department of Energy's Energy Sciences Network, conducts networking R&D and operates a large 100 Gigabit network linking research centres and universities. The SDN controller, the open source Floodlight Project design, oversees the network comprising Brocade's 100 Gigabit MLXe IP router and Infinera's DTN-X platform.

The goal of provisioning and optimising traffic across the routing, switching and optical layers has been a work in progress for over a decade. System vendors have undertaken initiatives such as External Network-Network Interface (ENNI) and multi-domain GMPLS but with limited success. "They have been talked about, experimented with, but have never really made it out of the labs," says Mike Capuano, vice president of corporate marketing at Infinera. "SDN has the opportunity to solve this problem for real."

"In the world of Web 2.0, the general approach is not to sit and wait till standards are done, but to prototype, test, find the gaps, report back, and do it again"

"SDN, and technologies like the OpenFlow protocol, allow all of the resources of the entire network to be abstracted to this higher level control," says Daniel Williams, director of product marketing for data center and service provider routing at Brocade.

Daniel William, BrocadeInfinera and ESnet demonstrated OpenFlow provisioning transport resources a year ago. This latest demonstration has OpenFlow provisioning at the packet and optical layers and performing network optimisation. "We have added more carrier-grade capabilities," says Capuano. "Not just provisioning, but now we have topology discovery and network configuration."

“The demonstration is a positive step in the development of SDN because it showcases the multi-layer transport provisioning and management that many operators consider the prime use case for transport SDN,” says Rick Talbot, principal analyst, optical infrastructure at Current Analysis. "The demonstration’s real-time network optimisation is an excellent example of the potential benefits of transport SDN, leveraging SDN to minimise transit traffic carried at the router layer, saving both CapEx and OpEx." 

Using such an SDN setup, service providers can request high-bandwidth links to meet specific networking requirements. "There can be a request from a [software] app: 'I need a 80 Gigabit flow for two days from Switzerland to California with a 95ms latency and zero packet loss'," says Capuano. "The fact that the network has the facility to set that service up and deliver on those parameters automatically is a huge saving."

Such a link can be established the same day of the request being made, even within minutes. Traditionally, such requests involving the IP and optical layers - and different organisations within a service provider - can take weeks to fulfill, says Infinera.

Current Analysis also highlights another potential benefit of the demonstration: how the control of separate domains - the Infinera wavelength and TDM domain and the Brocade layer 2/3 domain - with a common controller illustrates how SDN can provide end-to-end multi-operator, multi-vendor control of connections.

What next

The Open Networking Foundation (ONF) has an Optical Transport Working Group that is tasked with developing OpenFlow extensions to enable SDN control beyond the packet layer to include optical.

How is the optical layer in the demonstration controlled given the ONF work is unfinished?

"Our solution leverages Web 2.0 protocols like RESTful and JSON integrated into the Open Transport Switch [application] that runs on the DTN-X," says Capuano. "In the world of Web 2.0, the general approach is not to sit and wait till standards are done, but to prototype, test, find the gaps, report back, and do it again."

Further work is needed before the demonstration system is robust enough for commercial deployment.

"This is going to take some time: 2014 is the year of test and trials in the carrier WAN while 2015 is when you will see production deployment," says Capuano. "If service providers are making decision on what platforms they want to deploy, it is important to chose ones that are going to position them well to move to SDN when the time comes."