Alan Weissberger Software Defined Network

Ciena and Research Network Partners Work to Make Carrier WAN-SDN Realizable

Introduction: #

Ciena has teamed up with three research networks to build the industry’s first SDN based carrier-WAN, which will be accessible “on demand” by researchers.  The venerable optical network equipment company is working with CANARIE, Internet2 and StarLight on this intriguing research project.

  • Canarie Inc. is Canada’s advanced research network
  • Internet2 is a university consortium that develops advanced networking applications
  • StarLight is a 1GigE and 10GigE switch/router facility used as a proving ground by both the academic and commercial communities

When completed, this network will unite all of the key packet, optical and software building blocks required to demonstrate and prove the optimization and monetization benefits of SDN OpenFlow-enabled, multi-layer WANs. The network will provide a modular carrier-scale software control system that leverages open source components, features high-impact, real-time analytics software which improves optimization and monetization in dynamic service environments. With this network platform, researchers can trial new technologies on a fully operational network without having to build a unique infrastructure for every use case.

Ciena’s SDN Vision: Multi-layer Carrier WAN SDN #

Ciena believes that SDN is key to the next wave of value creation for service providers as it brings network programmability together with powerful new software intelligence capabilities to help monetize and optimize network assets in dynamic service environments. This new network platform will help speed SDN development for carriers and enable Ciena and its partners to explore and refine practical paths to SDN adoption and realization of its benefits. This is the first time a commercial network vendor, (e.g. Ciena), has been connected to an international span of National Research Network (NREN).

Chris Janz, VP of Market Development at Ciena, says the prototype network will be designed to demonstrate real-time analytics applications deliberately focused on two separate benefits of SDN: optimizing the network so that it can do more at a lower operating cost; and exploring how SDN could enable mass customization of services to generate more revenue.

Network Topology, PHY layer, and Network Equipment: #

Ciena and partners to flesh out the needs to make Carrier WAN SDN practical.
Ciena and partners’ Research-on-Demand testbed focusing on multi-layer Carrier WAN SDN

As shown in the accompanying figure, the network initially connects Ciena’s corporate headquarters in Hanover, Maryland, U.S. with Ciena’s largest R&D center in Ottawa, Ontario, Canada. International connectivity is achieved with Internet2 through the StarLight International/National Communications Exchange in Chicago and CANARIE, Canada’s national optical fiber based advanced R&E network. This research network has the potential to cross connect data flows from Ciena R&D labs to virtually any NREN or university research facility across the globe. The network architecture currently spans 2500 km with packet optical transport. The network footprint is expected to grow significantly in 2014.

The ITU-T OTN framing and PHY is used for packet optical transport by Ciena network elements (NEs) from the company’s 6500 and 5400 converged packet-optical product families. Their packet-optical products also perform ODU switching as well as layer 2 switching and (in the case of 6500) wavelength switching (i.e. ROADM). All these functions will be exercised in the test bed by the multi-layer SDN controller.

According to Mitch Auster, Senior Director, Market Development at Ciena, the company has built a “proof of concept” multi-layer SDN controller which uses Open Flow v1.3 with extensions for optical transport as the Southbound API/Protocol to/from Ciena’s aforementioned packet optical NEs. The company has defined its own RESTful Northbound API (for which there are no standards) to business applications, such as Cloud Orchestration software.  This enables service providers to have some degree of programmability and control over the multi-tenant research network.

Quotes from Mitch Auster, Ciena’s Sr Director, Market Development (via email): #

“Several of the benefits of SDN – such as enabling business applications to drive policy-bound network connectivity through an open API, and enabling centralized global network resource optimization – can be provided today for carrier WANs, though we currently need to leverage certain capabilities of existing network management systems and/or distributed control planes. Ciena’s V-WAN NSM is in various stages of operationalization with carriers to deliver these benefits for applications such as Network as a Service and on-demand Data Center Interconnect for Hybrid Infrastructure as a Service and Cloud Backbone optimization.”

“OpenFlow and OF-config hold great promise in enabling a logically centralized network controller to subsume more and more of the embedded control plane and vendor-distinct management system functions; however, it may be a couple years before a carrier-grade WAN can be fully OpenFlow-controlled at the packet layer, and it is likely that the optical transport layer will continue to leverage some distributed control plane and/or vendor-distinct management capabilities – especially at the photonic layer – for the foreseeable future.”

“Aspects that are not yet fully or adequately enabled by OpenFlow or OF-config include fault and performance management, fast restoration beyond simple protection, NE capabilities reporting and configuration, and integrated hybrid operation to name a few. And of course, the recommendations to extend these protocols for optical transport aren’t scheduled to be completed until April 2014.”

Update from Lyndon Ong, Ciena & Chairman of the  ONF Optical Transport Group:

“The Optical Transport Working Group (OTWG) is making good progress following the plan identified in its charter. We are focusing initially on enterprise and service provider use cases, recognizing the importance of identifying the applications for SDN in carrier and research networks.”

Perspective and Closing Comments:

For SDN to be deployed in a production, revenue generating WAN, the service provider will need a lot more than just an Open Flow protocol based Control plane residing in a centralized SDN Controller.  Mitch Auster identified a few of those in his last quote above.

Our list includes: signaling for provisioning, reconfiguration and other functions; comprehensive network management, OSS and billing systems; capacity planning tools; OAM and performance monitoring, fault detection and isolation; fast software controlled restoration (or some form of protection switching). All those new protocols, methods and procedures will have to be compatible with the control and management functions standardized by the ONF (e.g. Open Flow, Optical Transport, etc) and the OTN PHY layer.

Yet there is scant effort underway to define the essential missing pieces!  We know and have written about the ONF Optical Transport Working Group which Ciena’s Lyndon Ong is Chairing (see quote from him above). And we are up to date on the emerging ITU-T standards work on SDN. But it’s way too early in the standards process for anything of substance (i.e. that’s implementable) to have been created. In fact, there isn’t even draft text for any of the missing pieces identified earlier in the previous paragraph.

Hence, this author believes that carrier SDN will initially be restricted to interconnecting telco data centers and 3rd-party DCs, where interconnect is offered as a service by a fiber optic based carrier. Later, Carrier -SDN will be used  for newly built telco DC networks (e.g. IP-Ethernet for the data plane with SDN-Open Flow as the control plane-data plane interface within a DC). Those configurations are somewhat akin to “greenfield” deployments where there is no installed base of networking equipment. Lastly, Carrier-WAN SDNs will be deployed in pockets of the carrier’s network which are being built out and/or expanded.

Nonetheless, the progress of this research network should be closely watched to see what problems are identified with Open Flow-SDN and how Ciena will work with the three NRENs to provide the missing pieces in their existing NEs and new software.  In addition, “Ciena expects to work with their carrier customers (within the context of this research network and beyond) to better understand and address these issues.”

Ciena’s Joe Berthold, PhD Physics (who Alan first interviewed in Spring 1998 for a research report on DWDM): #

“A few general comments on Alan’s Perspective section of this article.

First he recognizes that OpenFlow is a very low-level interface, and of itself it does not provide a complete service solution. Second, SDN is certainly a broader concept than OpenFlow, and one should not expect large service providers to first install new OpenFlow enabled equipment and OpenFlow controllers before they test out concepts in network programmability.

Along these lines I would second the comments Alan noted above that “SDN control” of OTN electrical switching equipment and photonic switching equipment are likely to make use of existing lower level signaling and control mechanisms, with an open API that allows applications to control network configurations.

On the topic of missing standards, I would observe that there has been a great deal of work in network management, capacity planning, OAM and performance monitoring that does not need to be redone. What is needed is agreement on which of potentially several options are most useful and should be supported above a higher level API. We have seen many times in the past that completion of standards does not necessarily lead to adoption by large service providers, who need a compelling business case to change their current operations methodology, which is often highly automated. I look to the work that we will do with the R&E community to help develop applications that will be compelling, and will drive speedier adoption.

In the meantime, I look to large service providers to identify application scenarios and network domains where they can try out these new concepts without disrupting their existing infrastructure and operations.”

References (from Ciena): #

Author Alan Weissberger

By Alan Weissberger

Alan Weissberger is a renowned researcher in the telecommunications field. Having consulted for telcos, equipment manufacturers, semiconductor companies, large end users, venture capitalists and market research firms, we are fortunate to have his critical eye examining new technologies.

3 replies on “Ciena and Research Network Partners Work to Make Carrier WAN-SDN Realizable”

Thanks Alan for writing this piece. This sort of real-world test platform seems to be what SDN needs to prove concepts and further identify specific gaps in specifications and incompatibilities in implementations.

Mr. Berthold’s comments are insightful. Would he also be open to working with small carriers as well to test the application scenarios and network domains?

Thanks Ken, I was told Joe is on vacation this week so won’t be able to respond to your query. I would suggest interviewing him in early September regarding a follow on Ciena’s plans to test the application scenarios and network domains. Joe is one of the few people I’ve met that understands both the physics of optical transmission as well as the systems aspects. Before joining Ciena in 1997, Joe worked at Bellcore and before that AT&T Bell Labs. He has a PhD in Physics from Brown University and has done post doctoral work at Cornell University. Joe is highly respected by this author and by many Ciena employees!

Ken asked Ciena in an email: I am curious if there might be a play for smaller operators (e.g. a Vermont Telephone or a consortium of smaller operators) to play in the SDN sandbox you are creating.

Hi Ken. Ciena would consider the inclusion of any potential network operator, not based on size, but rather on the merits of, and the wherewithal to carry out, the work proposed. We encourage interested operators to contact their Ciena sales representatives to explore such opportunities.

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