By David Le Goff – 6WIND Product Marketing Manager
Last week I attended the Carrier Cloud Summit 2012 in Paris, including an interesting SDN (Software-Defined Networks) workshop on the first day at which I was pleased to deliver a presentation during a well-attended session that also included speakers from Cisco, Juniper and Alcatel-Lucent.
I participated in several interesting offline discussions about the evolution of both carrier networks and data center networks, as well as key challenges in these markets. There was strong consensus that it will take several more months for the industry to agree on SDN standards and operational plans.
It was interesting that both Verizon and Orange stated that some parts of the networks don’t need to be updated with SDN technology, such as the core network which is adequately provisioned already for near-term increases in traffic. Both the carrier edge and data center networks, however, need to be redesigned for improved flexibility, given the lack of visibility into the future mix of applications or the growth in workloads. Scalability remains a significant challenge.
Verizon stressed that currently Internet traffic is growing at 60-70% CAGR and there are already an increasing number of software implementations of network functions, running on commodity hardware (such as flow-based traffic routing, content filtering, CDNs and analytics). Key enablers for the migration to cloud/SDN architectures are high performance COTS hardware and network virtualization solutions, along with new business models for network software.
Verizon reiterated that network virtualization is applied to equipment beyond switches and that they expect carriers to focus on monetize the network first, before thinking about SDN implementations. As always, business pressures take priority over technical elegance…
Regarding the actual definition of SDN, there were many discussions about all the overlay networks that are emerging to resolve scalability issues both at Layer 2 and Layer 3, such as PCE, OpenFlow, VXLAN, STT, NVGRE etc. protocols. There is evidently still good business for proprietary networking equipment…
Cisco mentioned that, given typical consumer behaviors as well as the quality of the applications being used, no one could doubt that OTT (Over The Top) providers have to be closely involved in the definition of network programmability, so that exposing northbound APIs from network equipment was a strong requirement. CLI-based hop by hop network management is inefficient in enabling a good customer experience from the OTT side. The main challenge is to define which kind of SDK, framework and APIs need to be published, given that the only public example so far is the Quantum use case from OpenStack.
Again, Juniper pointed out that in parallel with defining the (southbound) interfaces between the controller (control plane) and the forwarding (data plane), there were critical challenges in defining the northbound interfaces between the controller and the network users.
What are your thoughts on this topic? What do you expect to happen in terms of SDN’s adoption? What are the key issues (both business and technical) that the industry needs to resolve to accelerate this adoption? Is there a “killer use case” for this technology that will trigger a sudden increase in deployments?