Ciena’s Liquid Spectrum: Are They Taking It Far Enough?

The Ciena announcement of what they call Liquid Spectrum has raised again the prospect of a holistic vision of network capacity management and connectivity management that redefines traditional OSI-modeled protocol layers.  It also opens the door for a seismic shift in capex from Layers 2 and 3 downward toward the optical layer.  It could jump-start SDN in the WAN, make 5G hopes of converging wireline and wireless meaningful, and introduce true end-to-end software automation.  All this, if it’s done right.  So is it?  I like Ciena’s overall story, including Liquid Spectrum, but I think they could tell, and perhaps do, more.

Liquid Spectrum, not surprisingly, is about systematizing agile optics to make the optical network into more of a collective resource than a set of dedicated and often service-specific paths.  There is no question that this could generate significantly better spectrum utilization, meaning that more traffic could be handled overall versus traditional optical networking.  There’s also no question that Liquid Spectrum does a better job of operationalizing spectrum management versus what even agile-optics systems have historically provided.

Liquid Spectrum is a better optical strategy, but that point raises two points of its own.  First, is it the best possible optical strategy?  Second, and most important, should it be an “optical” strategy at all?  These two questions are related, and harder to answer, so let’s start with the simple case and work up.

The most basic use of optical networking for services would be to provide optical routes to enterprise or cloud/web customers for things like data center interconnect (DCI).  For this mission, Liquid Spectrum is a significant advance in terms of simple provisioning of the connections, monitoring the SLA, and affecting restoration processes if the SLA is violated.  If the operator has latent revenue opportunity for this kind of service, then Ciena is correct in saying that it can bring in considerable new money.

As interesting as DCI is to those who consume (or sell) it, it’s hardly the basis for vast optical deployments even in major metro areas.  The primary optical application is mass-market service transport.  Here, the goal isn’t to create new services as much as new service paths, since truly new connection services would be very difficult to define in an age where IP and Ethernet are so totally adopted.  Liquid Spectrum’s ability to improve overall spectrum efficiency could mean that more transport capacity for services would be available per unit of capex, which is an attractive benefit.  The coming improved metrics/analytics of Liquid Spectrum will improve this area further.

It should be possible to combine some of the principles of intent-modeled networking, meaning SLA-dependent hierarchies, to define optical transport as a specific sub-service with an SLA that optical agility offered by Liquid Spectrum could then meet.  Since optical congestion management and path resiliency would be addressed invisibly within these SLAs and model elements, the higher layers would see a more reliable network, and the operations cost of that configuration should be lower.  It’s hard to say exactly how much because the savings are so dependent on network topology and service dynamism, but we’re probably talking about something on the order of a 10% reduction in network operations costs, which would equate to saving about a cent of every revenue dollar.

That’s not insignificant, but it’s not profound given that other strategies under review could save ten times that amount.  The reason why optical networking, even Liquid Spectrum, fall short of other cost reduction approaches is the tie to automation of the service lifecycle.  Obviously, you can’t automate the service lifecycle down so deep that services aren’t visible.  Service automation starts at the protocol layer where service is delivered because that’s where the money meets the network.  Optics is way down the stack, invisible unless something breaks, which means that to make something like Liquid Spectrum a meaningful pathway to opex savings, you have to tie it to service lifecycle management.

Ciena provides APIs to do just that, and they cite integration with their excellent Blue Planet orchestration platform.  There’s not much detail on the integration; Blue Planet is mentioned only in the title of a slide in the analyst deck and the slide itself shows the most basic of diagrams—a human, a box (Blue Planet) and the network.  This leaves open the critical question of how optical agility is exploited to improve service lifecycle management.  Should we look at optical agility as the tail of the service lifecycle automation dog?

You absolutely, positively, do not want to build a direct connection between service-layer changes and agile optics, because you risk having multiple service requests collide with each other or make inconsistent requests for transport connectivity.  What needs to happen is an analysis of the transport conditions based on service changes, and the way that has to happen would necessarily be reflected in how you model the “services” of the optical layer and the services of the layers above.  We don’t have much detail on Blue Planet’s modeling approach, and nothing on the specific way that Liquid Spectrum would integrate with it, so I can’t say how effective the integration would be.

Another thing we don’t have is a tie between Liquid Spectrum and SDN or “virtual wire” electrical-layer technology.  There are certainly cases where connectivity might require optical-level granularity in capacity and connection management, but even today those are rare, and if we move more to edge-distributed computing they could become rarer still.  It would be logical to assume that optical grooming was the bottom of a grooming stack that included electrical virtual-wire management as the layer above.  I think Ciena would have been wise to develop a virtual-wire strategy to unite Blue Planet and their optical products.  Logically, Ciena’s packet-optical approach could be integrated with modern SDN thinking, and it’s a referenced capability for Blue Planet, but nothing is said in the preso about packet optical or Ciena’s products in that space.

There have been a lot of optical announcements recently, and to be fair to Ciena none of them are really telling a complete network-infrastructure-transformation story.  ADVA, who also has a strong orchestration capability, did an even-more-DCI-centric announcement too, and Nokia told an optical story despite having, in Nuage, an exceptional SDN story to tell.  Product compartmentalization is driven by a lot of things, ranging from the way media and analysts cover technology to the desire to accelerate the sales cycle by focusing on a product rather than boiling the ocean.  However, it can diminish the business case for something by demanding that it be considered alone when it’s really part of a greater whole.

You have to wonder whether this compartmentalization issue is a part of a lot of technology problems.  Many emerging technologies, even “revolutions”, have been hampered by compartmentalization.  NFV and SDN both missed many (perhaps most) of the benefits that could drive them forward because they were “out of scope”.  It seems that biting off enough, these days at least, is equated to biting off too much.

I think Ciena needs to bite a bit deeper.  They have an almost unparalleled opportunity here, an opportunity to create a virtual-wire-and-optics layer that would not only improve operations efficiency but reduce the features needed in Layers 2 and 3 of the network.  That would make it easier to replace Ethernet and IP devices with basic SDN forwarding.  Sure these moves would be ambitious, but Ciena’s last quarter didn’t impress the Street.  They need some impressive quarters to follow.  Competition is tough in optics, and the recent success of the open-optical Facebook Voyager initiative shows that it would be easy to subsume optical networking in L2/L3 devices rather than absorb electrical-layer features in optical networks.  If Ciena and other optical vendors lose that battle, it’s over for them, and only a preemptive broad service-to-optics strategy can prevent the loss.

Ciena has the products to do the job, and Liquid Spectrum is a functional step along the way.  It’s also an example of sub-optimal positioning.  You can argue that the major challenge Ciena faces is that it wants to be strategic but sells and markets tactically.  If you have a broad product strategy you need to articulate it so that your product symbiosis is clear.  If that doesn’t happen, it looks like you’re a hodgepodge and not a unified company.  Ciena has a lot of great stuff and great opportunities, including Liquid Spectrum.  They still need to sing better.