For at least a decade, while vendors such as Cisco pressured enterprises to collapse their separate voice and data networks into a common IP infrastructure, the term "convergence" has often been used synonymously (and somewhat carelessly) with VoIP. In many circles, it still carries that meaning.

But then we had unified electronic mailboxes, which were very useful. Then came “twinning,” the ability of a single PBX phone number to reach you on a fixed or mobile phone to help avoid phone tag. Now there are pockets of seamless roaming between wired networks and different types of wireless networks.

All these capabilities represent progress. But for the most part, they have been tackled onesy-twosy by specialists in each area, while convergence is really about integration at many levels: combining multiple traffic types (voice, video, data) onto a common network is one. Merging applications, services, disparate physical networks, mobile devices, access methods, management and security into a common infrastructure are others. Gasp! It’s a tall order to merge all these components into one big mobility-enabled network.

With its Cisco Motion vision, announced last week, Cisco represents one of the few companies to tackle convergence in a big-picture, multidimensional way. The proof will be in the pudding. One component of the company’s Mobile Services Engine (MSE) 3300 platform, which sits at the heart of “The Vision,” is to begin shipping this week: the Cisco Context-Aware Software module (a.k.a. location tracking software). The module replaces Cisco’s 2700 location appliance.

Meanwhile, Cisco, long mum about how it intended to enable seamless signal handover between wireless networks (such as Wi-Fi and cellular or WiMAX) as users roam, has teamed with fixed-mobile convergence start-up Agito Networks on an MSE module to ship later this year. A wireless intrusion detection system module is slated to ship at the same time. A software module for collectively managing mobile clients is scheduled to ship in the first half of 2009.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.