Exploring the Operations Implications of the Verizon Model

The issue of operationalizing next gen networks and services is critical for operators, and it’s thus fitting to close this week’s review of the Verizon architecture with comments on OSS/BSS integration.  There are two questions to be answered; can the approach deal with the efficiency/agility goals that will have to be met to justify SDN/NFV, and can they accommodate the political divisions over the future of OSS/BSS.

Every Tier One I know is conflicted on the issue of OSS/BSS.  It’s not that the functions themselves are not needed (you have to sell services to make money) but that the functions are wrapped in an architecture that seems in every respect to be a dinosaur.  OTTs who have adopted modern cloud and web principles seem to be a lot more efficient and agile, and thus there’s a camp within each operator who wants to toss the OSS/BSS and remake the functions along web/cloud lines.  On the other hand, every OSS/BSS expert is going to resist this sort of thing (just like router experts resist transformation to SDN) and in any event, changing out your core business systems is always going to present risks.

The Verizon paper introduces the notion of layered service abstractions, starting at the top with an end-to-end retail-driven vision and ending at the bottom with virtual features/functions/devices.  These layers can be used to assemble a spectrum of network-service-operations relationships, and if these relationships are broad enough they could cover all the bases needed for benefit generation and political consensus-building.  Do they?  Let’s use the extreme cases to see, and let’s assume that we could graph the resulting structural relationship between OSS/BSS, independent EEO, and resources as a small-letter “y” whose left, shorter, branch could connect either up top or down lower.

One extreme case is to consider the OSS/BSS system to end with the high-level retail model.  A service is a set of commercially defined functions represented by SLAs.  Those functions, from an OSS/BSS perspective, are atomic—think of them as “virtual devices” if you like.  OSS/BSS systems deploy them, and customer portals and service lifecycle management processes treat the SLA parameters as representing service and resource behavior.

If you charted this in our “y” model, the left bar would join the main bar very close to the top.  EEO, then, would generate the vision of the service that operations systems saw, reducing the role of OSS/BSS to the commercial management of the service and leaving the issues of deployment and lifecycle management to EEO.

The other extreme case is to consider the OSS/BSS system to be responsible for the lowest-level virtual function/device models.  This would open two options for our conceptual structure.  The first would dive the left bar of the “y” downward to touch the resources, and the second would make the “y” into an “l” with a single branch.

The first approach would say that while EEO should be responsible for the deployment and lifecycle management, the OSS/BSS would see the lowest-level virtual devices.  This approach is friendly to current OSS/BSS models and perhaps to the legacy TMF approach, because it retains contact between “resources” and “operations” in its current form.  We have management systems today that operate, somewhat at least, in parallel with operations, and this would perpetuate that.

The second says that it’s fine to have EEOs but they need to be inside the OSS/BSS.  That component then has a linear relationship with all the model layers of the Verizon architecture.  This, I think, is the essential model for the TMF ZOOM project, though the details of that architecture aren’t fully open to the public at this point.  It would magnify the role of OSS/BSS, obviously, and preference the OSS/BSS vendors.  It also perpetuates the OSS/BSS and its role.

If you look at these extremes, particularly in terms of my “y” topology, you see that the Verizon approach of layers of models opens the opportunity to connect the OSS/BSS in at any of the modeling layers, meaning that you can slide that left bar up and down.  It also lets operators elect to integrate the functions “above the junction” of the left bar with the OSS/BSS, turning the model into an “I”.

All this capability isn’t automatic, though.  To understand the issues of implementation, let’s move from our “y” model to another one, resembling an “H”.

The left vertical bar of our “H” represents the OSS/BSS flow and visibility, and the right the EEO or incremental orchestration view.  Both these can coexist, but to make sure they don’t end up as ships-in-the-night competitors to management, there has to be a bridge between the domains—the crossbar.  The purpose of this is to establish a kind of visibility bridge—at the model layer where this crossbar is provided, there is a set of processes that convert between the two sets of abstractions that drive the OSS/BSS and EEO flows.  What is above the crossbar is invisible to the other side, and what is below it is harmonized—reflecting the likelihood that the two verticals represent different but necessarily correlated views.

Wherever this crossbar exists, the model for the associated layer has to provide both operations-friendly and orchestration-friendly parameters to represent the status, and that has to include lifecycle state if that state has to be coordinated between EEO and OSS/BSS.  Where the bar is set higher, meaning where the model layers represent more functional and less structural abstractions, the same parameters would likely serve both sides and little work is needed.  If you drive the bar lower, then you encounter a point where it’s desirable to have the operations view composed from the EEO view.

In an operator-defined architecture like Verizon’s, there’s no need to support a range of options for positioning the bar because the operator can make a single choice.  For a general architecture, vendors and operators would have to expect that the modeling at every layer provide for the coequal viewing of OSS/BSS and EEO elements, and support the necessary parametric derivations—both in read and write terms—to provide that capability.

The bidirectionality of the bar is important because it illustrates the fact that there are two parallel paths—operations and orchestration—and that these can be harmonized in part by “exporting” functionality from one to the other.  This is the answer to the political dilemma that OSS/BSS modernization seems to pose, because if you use the bar to shunt orchestration into OSS/BSS you “modernize” it, and if you use the bar to move OSS/BSS functions (by making them orchestrable) into the orchestration side, you essentially replace the current OSS/BSS concept.

I don’t see specific evidence of this “bidirectional bar” in the Verizon approach, but I think that all of the six vendors with current full-spectrum NFV capability could provide it.  It will be interesting to see if the emergence of carrier-developed models (like those of AT&T and Verizon) will raise recognition of the multiplicity of possible OSS/BSS-to-orchestration relationships, and create some momentum for a solution that can accommodate more, or even all, the options.