Ciena and partners build SDN testbed for carriers

Ciena, working with partners, is building a network to enable the development of software-defined networking (SDN) applied to the wide area network (WAN). The motivation in creating the testbed network is to boost carrier confidence in SDN while aiding its development.

 "When you get very serious vice presidents in tier-one carriers saying, 'This [SDN] is the biggest change in my career', there is something to it."

Chris Janz, Ciena

Many software elements will be needed for SDN in the carrier environment, spanning the network through to the back office. Much is made of the benefits SDN will deliver, but it is difficult for operators to gauge SDN's full potential until they transform their networks. Carriers also want the confidence that the industry will deliver the SDN components needed.  

To this aim, Ciena, along with research and education partners, CANARIE, Internet2 and StarLight, are developing the SDN test network. Carriers, research partners and Ciena's R&D team will use the network to experiment and validate SDN's benefits for packet and optical WANs.

Parts of the SDN network have already been demonstrated and Ciena expects the SDN test environment to be up and running in the next couple of months.  Many of the components are in prototype form.

"The goal is to leap to the end point by providing the key parts of the future system for a carrier-style SDN-powered WAN, thereby demonstrating conclusively the macro SDN service cases that people imagine can be delivered," says Chris Janz, vice president of market development at Ciena.

Another aim is to help carriers determine how best to migrate their networks to the future SDN framework.

Testbed

The testbed conforms to the Open Networking Foundation's SDN architecture that comprises three layers. "Two of them are software: business applications talking to a network controller system which drives the physical network," says Janz.

The business application layer includes such systems as customer management, service creation and billing. "What we think of as OSS/ BSS and cloud orchestration systems," says Janz. Components such as cloud orchestration systems and portals that simulate customer actions are being contributed by partners to exercise the testbed.

Ciena has chosen OpenFlow, the open standard, to drive the packet and transport layers. "This [SDN] is not the data centre, it is not all packet; it is a model carrier-style network," he says. 

The SDN controller is designed to add flexibility and open up the design. "There is a clear spirit in SDN that customers want to take more affirmative control of their competitive destiny," says Janz. "They do not want to be locked into services, features and functions that their vendors deliver to them and their competitors."

Ciena is part of OpenDaylight, the Linux-based SDN controller industry initiative, and this will be included. "There is a modular structure with internal interfaces," says Janz. "There is leveraging of some early generation open source components for part of the structure." 

The control system is designed to be the heart of what Janz refers to as 'autonomic intelligence' to deliver the sought-after benefits of SDN.

One such benefit is for carriers to contain their capital costs by better filling their networks with traffic - running them 'hotter'. "Can they move their networks from 35 percent average utilisation to 95 percent?" says Janz.

Software-based intelligence as delivered by SDN can match dynamically demand with fulfillment. "You have all the service demands coming into the [SDN] control system, and you have control at that point of the entire configuration and state of the network," says Janz.

Ciena has added real-time analytics software to the controller prototype to aid such optimisation. "It is piece parts like this that prove the postulated benefits of SDN," he says.

The platforms used for the network includes 4 Terabit core switches with 400 Gigabit packet blades and optical and Optical Transport Network (OTN) transport using Ciena's 6500 and 5400 converged packet-optical product families, all configured using OpenFlow.

The 2500km network will connect Ciena’s headquarters in Hanover, Maryland with the company's R&D center in Ottawa. International connectivity is provided by Internet2 through the StarLight International/National Communications Exchange in Chicago and CANARIE, Canada's national optical fiber based advanced R&E network.

"If we look ten years down the road, the whole [software] stack - from the bottom of the network to the top of the back office - will look different to what it does today"

Testbed goals

The initial goal is to implement key SDN services and prove use cases. The open testbed will run indefinitely, says Janz: "SDN will unfold and we view the testbed as a standing platform that will change over time with new software and hardware." In effect, the testbed will implement an end-to-end infrastructure whose state is controlled in fine detail by a centralised controller.

Janz cites mass-customised network-as-a-service (NaaS) as one service SDN-in-the-WAN can enable.

Traditional Ethernet connectivity is a static service where the customer requests a given bandwidth and specifies the end points. "It is a very limited template and once it is locked in, the customer generally can't change it," says Janz.

SDN promises more sophisticated connection services. "Instead of defining just the end points, you can define virtual end points," says Janz. All sorts of parameters can then be specified: bandwidth, latency, availability and the restoration required, and these can be changed with time. Moreover, all can be ordered using an application programming interface (API) to the orchestration system at the customer's site.

"It would enable the customer to have many effective service pipes rather than one big one, and resolve and match each of them to a specific application need or flow," says Janz. The customer can then optimise them as the needs of each changes with time.

The benefits to the operator include better meeting the customer's needs, and an ability to charge across multiple service parameters, not just two. "That should be the path to greater revenue," says Janz.

The trick is managing such a system. "Can you price it effectively and know that you are targeting maximum revenue? Can you co-manage all these customer changes while respecting the changing service parameters of each?" says Janz. "You need the critical mass of piece parts to show that such a situation is workable and that, hey, I can make more money with a service like that."