By combining Firefox's new WebRTC support, Ericsson's Web Communication Gateway, and AT&T's API Platform, Mozilla has demonstrated calls, text messages, and video calls all being made from within the browser. It's all in a proof-of-concept application AT&T calls WebPhone, and Mozilla will demonstrate WebPhone next week at the Mobile World Congress conference.

With the right phone operator support, the plugin-free technology can potentially offer a full range of telephony services through the browser. This decouples traditional phone services from the phone itself, potentially enabling access to the phone and text messages from anywhere with an Internet connection and WebRTC-enabled browser. The demo is currently limited in scope, with AT&T planning to roll out an alpha version of the full API "in the near future."

AT&T describes WebPhone as a "vision for the future of seamlessly integrated communication." More than that, however, it's a vision for the network operator as dumb pipe provider. Put that browser on a phone—perhaps one running Firefox OS—and you can do away with the voice connection entirely. Just place everything, voice and data alike, over the data connection.

For end users, the advantage is universal access. For example, if visiting a foreign country you could pick up a cheap data SIM on the foreign operator, but still be able to place and receive calls and texts on your domestic phone number. Receiving a text while working on a desktop PC could simply pop up an on-screen alert with no need to rummage around in your pocket or purse to see why your phone vibrated.

WebPhone could also be seen as a precursor to giving traditional mobile telephone systems more of the flexibility offered by systems like Skype and Google Voice. It should be relatively simple to build the kind of voicemail recording and transcription service that Google Voice offers on top of a WebPhone-like platform (AT&T's APIs already provide some of these capabilities through software from Tropo). It has the same universality of access that Skype offers: you can make calls from your number even on someone else's phone or PC. And I can't be alone in preferring to make phone calls by Skype so that I can use my headset; routing regular calls through the PC would be welcome for that alone.

Whether providers like AT&T embrace this future is an open question. The flexibility means users could just as well pick competing voice services—as they already do for international calls—leaving their network operators as nothing more than a dumb pipe for data.

Skype's success suggests this will happen one way or another anyway. By promoting this kind of technology and offering its APIs, AT&T could be ensuring that its voice network still has a role to play in the dumb pipe future.