One of the positive things said recently in the SDN space is that Nokia is very committed to Nuage, the SDN unit that Alcatel-Lucent acquired several years ago. Alcatel-Lucent never played Nuage well in my view, and it offers a number of highly relevant features, enough to make it my favorite among the SDN plays. Now, the combination of support from the parent and market opportunity may be playing in its favor. As is often the case, though, there are still questions. Just how much “commitment” is Nokia offering here?
There are three broad technical models of SDN. One is the overlay or Nicira model, in which tunnels created on top of arbitrary infrastructure let you create a connection network whose structure and rules for connectivity and traffic flows are independent (largely as we’ll see) from the transport underlayment. The second is the OpenFlow model where forwarding rules combine to create connectivity at (theoretically) L2 or L3. The final one is a melding of these two models. Nuage represents this last approach.
Nicira proved that in today’s relatively low cost-per-bit world you can afford to waste some bandwidth with additional headers, needed to create the overlay. The overlay model is nice because it can span any arbitrary set of L2/L3 switching/routing networks and create what appears to be a unified model. You can see this approach maturing in the SD-WAN offerings of today. However, overlay networks are just traffic to the transport underlayment, which means that it’s difficult to provide integrated QoS or traffic management. For network operators, a pure overlay model is also hard to differentiate from competitor managed service providers, who can ride on your underlayment to offer their services.
The OpenFlow model solves these problems with SDN controllers and centralized traffic and QoS management, but SDN is a revolution in cost and operating procedures. Because major vendors don’t want to lose revenue, their SDN support has largely focused on making OpenFlow control work on legacy devices, which offers only limited utility versus the native L2/L3 protocols. With a little SDN, you don’t get much benefit. Without starting with a little, you don’t get to a lot, and so this model has had growing pains outside the data center.
Nuage’s approach has been to enhance the overlay model in a number of interesting ways. One is that APIs provide a means for integrating traffic engineering at the SDN level with transport traffic engineering. This lets network operators with real, owned, assets integrate their stuff vertically to differentiate the services it provides. Another is to provide API integration with cloud hosting environments of all types (hypervisor and container) and also support Network Functions Virtualization connectivity. A third is to virtualize networks all the way to the user in any arbitrary, useful, way.
Truly virtualized networks integrated with data center networking and transport QoS would be a revolution in a number of ways. A true virtual overlay could be pushed out to any connected user simply by giving that user a device/app that could terminate the overlay network properly. Armed with that capability a service could support a worker on a phone as easily as a fixed-Ethernet branch location, and in the latter could then extend out virtual-worker terminations too. By linking workers to communities/roles that defined their application access rights, then linking those roles back to the proper data center application-specific VPN, you’d have network security and isolation without firewalls.
All of this is very consistent with network connections for the cloud, obviously, but it’s also good for NFV, and Nuage enhanced their stuff to support SDN connections for service chaining. In fact, while Alcatel-Lucent was independent, Nuage seemed to be drifting more to a role of cloud connectivity and NFV and less one of branch networking. You can see the transition in the Nuage presentations even going back only two years; they were much more “universal SDN” than “cloud/NFV” in the old days.
While neither the old nor the new positioning favored a radical virtual-wire positioning, the fact is that any overlay SDN has the potential to at least complement virtual-wire networks. For those who don’t recall the blogs on that topic, “virtual wire” networks use tunnels and software instances of switching/routing to create L2/L3 services instead of segmenting transport switches/routers. If you could create virtual-wire partitioning of optical paths and then add overlay SDN, you could create pretty much everything—even (if you were careful in your choice of vendors and the approach you took) the Internet.
This is interesting because it puts the Nokia/Nuage combination in potential competition with the from-the-optical approaches that could be developing from ADVA and Ciena, and potentially Nokia could also support that bottom-up model. The most impactful thing that could happen in network infrastructure (and in network equipment sales) would be subducting most of the reliability and availability and aggregation features out of L2/L3 devices into SDN-groomed virtual wires, then building overlay IP and Ethernet networks using software instances hosted (in the cloud, by NFV, or however you’d like to see it.
The issue in both the branch and virtual wire models of networking is the same; can you virtualize the connection layer of the network to provide better isolation of services and at the same time reduce opex and capex. I think the answer is “Yes!” but the issue is complex and the players who have the most incentive (and in the case of Nokia, the most collateral) to solve the problem often have the most at stake in the status quo as well.
If Nokia were the only player who could do this, I’d be inclined to bet that they’d sit on their hands, Nuage-wise, just like Alcatel-Lucent did. They have inherited the Alcatel-Lucent portfolio, they have to pay back on their investment in Alcatel-Lucent, and Nokia was never a progressive marketing/positioning company. If there’s anything that would demand progressive thinking in networking, both the branch office and virtual-wire transformations would top my personal list. But remember that ADVA and Ciena can push virtual wire, and so can Brocade. Dell/VMware would be happy to promote overlay SDN and perhaps the branch model, and maybe even virtual-wire as well. Thus, Nokia may have little choice but to try aggressive marketing on for size. They can’t suppress change, only refuse to profit from it!