When Metaswitch Networks says the company aims to become a “platform,” you should take notice. The question isn’t “what product will Metaswitch introduce next?” but “what does it mean if Metaswitch can become a platform?”
The phrase “global and mobile,” in conjunction with platform, should suggest some answers. Translate that as “everywhere.” So what would it mean if applications and services are available “everywhere?”
It means Metaswitch has to enable apps that work on mobile and fixed networks, that move sessions between mobile and fixed domains, seamlessly. That means allowing third parties to create apps that work in both domains. And be clear: that capability does not imply anything about the “ownership” of physical network assets.
It does mean that apps work “everywhere.” That feature necessarily means some combination of “on access assets I own” as well as “access assets I do not own.” In other words, the old notion that “over the top” is something “other people do” has to be reinterpreted.
Over the top is something today’s fixed-line and mobile service providers will be doing, themselves, in the future. In fact, it could hardly be otherwise. It is built into the way all software gets written and used.
The Open Systems Interconnection model(OSI model) is the foundation for the way all software gets written these days. But the OSI model also is, in many ways, a way of describing the current communications business ecosystem as well.
The OSI model idea structurally separates seven functions, with “application” at layer seven and physical layer at layer one. That should strike you as describing the relationship between “over the top” applications of every sort and the network used to deliver the app.
As applied to any business using a software-heavy product, that means there can be a separation of facilities, entities using facilities to create “communication” or “content” services, and application creators. The form will follow the function, you might say. 
For software developers, service providers and consumers and users, the advantages of using the OSI model are numerous. OSI Model Features and apps can be created or changed without requiring modification of other parts of the complete communications “stack.”
In other words, a user can switch from one supplier of a word processing or instant messaging app to another without “changing networks.” If a user wants to switch from Microsoft Office to Google Docs, that doesn’t mean a PC or network access provider also has to be changed.
Some of you will quip here that it isn’t always easy to sustain a single session, on a single network, using a single device, either. That’s also true, but is not a defect of OSI!
However, in principle, and over time, in practice, a user should be able to start a session of some sort (voice or video or Web app) and then maintain the session even when switching from one network to another, from fixed to mobile, for example.
In the legacy world, physical layer access was a matter of geography. A supplier needed permission from a government authority to operate a network, to support an application.
Cable operators needed municipal permission to build a network to sell television. Telcos needed certificates of convenience and necessity. Cloud computing and OSI, plus widespread and universal broadband, changes much of that older model.
A company that might also be a telco or cable company or ISP, might or might not “own” physical assets when creating and then delivering applications.
The OSI model is a way of allowing developers to create software in an abstracted way, without having to know all the details of other parts of how a particular network works.
It also is an analogy for the way the communications and entertainment business already is starting to change. “Over the top” is not just something “other companies” do.
It is something layer one asset owners also are starting to do. The only question, over time, is when over the top gets embraced more widely as “my” business strategy, not just “the other guy’s strategy.”
You wonder how much longer it will be before that is more widely recognized and incorporated into core business strategies.
