Google Voice reverses the traditional arrangement of call control with added applications. It effectively outsources basic call control. Ignoring the burden of phone system hardware (and 911 liability), and focuses only on the applications. Rather than develop proprietary interfaces to work with each phone system, they simply call phones to make them ring; introducing the “PSTN API.”
Effectively cherry picking key components of the PBX/communications puzzle, and combining these applications with (potentially) a huge base of related applications. Consider the fact that Google is actively engaged in managing, designing, and implementing applications around presence, chat, video, calendar, location awareness, cell phone APIs, and more.
PBX makers are taking a similar strategy with new desktop clients and mobility applications. The difference is Google’s sandbox is global and hardware-agnostic. Not to mention, these applications and services are generally available for no charge or a small charge; some even open sourced.
Conversely, the established PBX model is very different where new features are generally tied to new phone models requiring new software releases. Key features are limited to internal or federated peers via licensed client software.
There is no doubt that Google Voice is disruptive to the telecom industry. Google Voice is unbundling applications from call control using a PSTN API, putting applications into the cloud with new economics, offering new levels of simplicity and customization through web based GUIs, and totally separating delivered value from specific hardware.
See the full feature at: NoJitter.com.