Some enterprises are already starting to build a post-PBX strategy even though implementation won't occur for some time.

A session at Enterprise Connect called "The Post-PBX Platform: How Real, When and From Whom?" drew a standing-room-only crowd of almost 200, all of whom stayed for the entire 60 minutes. Obviously, this topic hit a nerve, even though I doubt that anyone in the audience actually believed a new era had arrived...yet.

But the technology and industry are moving in that direction; the old "refrigerator" PBX model is already a thing of the past. For the past decade, we've seen the relentless disassembly of the PBX, to the point where credible and implementable architectures now can be built without a PBX--its functionality, instead, carved up and delivered via a widely distributed network of servers.

And while it's no surprise that companies like IBM and Microsoft, which don’t have a stake in PBXs deliver these designs, they're also available from Cisco, Avaya and virtually all of the traditional PBX suppliers. Even NEC, which hasn't exactly led the pack in moving from traditional PBX-centric thinking, announced a new virtualized software platform at Enterprise Connect, that can run on-premises or from the cloud. Both Jay Krauser, director of enterprise product marketing, and Todd Landry, SVP for product strategy, touted the fact that NEC’s booth contained no hardware--instead of phones and boards they were showing software systems, UIs and apps. To be sure, NEC's new products run off NEC hardware, but like the other vendors in this space, NEC acknowledges that the value proposition has shifted to software and apps rather than iron and silicon.

Progress towards a post-PBX era shows up in other ways as well. Part of the appeal of Unified Communications is that it reflects a growing workforce reality: Lots of folks don't rely on a desktop phone, but instead on smartphones, laptops, netbooks and, soon, tablets. And their numbers are increasing. In this environment, a strategy that is based on communications equipment optimized for calls instead of sessions, and for voice bits instead of data bits, simply makes no sense.

Choice in end points and diversity of media trump the high levels of availability and reliability that traditional PBX architectures provide. Indeed, perhaps we have already entered an era when no single architecture will dominate. Yankee Group's Zeus Kerravala predicted in a recent post on NoJitter. "Decades from now organizations will have multiple communications platforms and build some functionality on each, use some cloud based applications and a handful of purpose built applications."

Kerravala continued, "Where communications need to be integrated to one another, 'communications middleware' will exist to be that required higher abstraction layer. Avaya's ACE platform is actually a good example of communications middleware that could be used to tie communications functionality together."

The ways in which this middleware layer evolves will be critical for whatever the post-PBX platform becomes. And middleware’s importance grows as hope fades for any meaningful progress on interoperability. At one of the featured sessions at Enterprise Connect, moderator Jim Burton asked the audience to indicate whether interoperability was important and the response was overwhelmingly positive; he then followed up and asked whether the vendors were delivering on interoperability and again, the audience response was overwhelming, but on the negative side.

The fact is, very little is happening to make unified communications interoperability a reality. A UC Interoperability Forum exists, but without Avaya, Cisco or IBM as members, the Forum’s potential impact is severely stunted. In the absence of interoperability, middleware and integration services assume greater importance.

So, while many of the elements for a post-PBX platform era exist, they don’t quite hang together, at least not yet. We know major migrations in communications and collaboration take time. More than a decade has passed since IP Telephony arrived on the scene but still the vast majority of U.S. enterprises have yet to complete their rollouts. Similarly, UC has been on the scene for at least four years but its market penetration remains low.

Still, from the interest in this topic at Enterprise Connect, it's clear that some enterprises are already starting to build a post-PBX strategy even though implementation won’t occur for some time. It's the early stages, but this migration has already begun.