Yet about Google Call

Due the amount of comments and emails received, I will reply to them in a post.

• How does the Authentication works?
• That is one key reason for using their established XMPP channel for placing the calls. The user is already authenticated in GMail and Google Talk. So the request is sent through the authenticated XMPP network to their XMPP Component responsible to offer SIP Gateway. From that moment one the component will convert the Jingle Signaling from the Google Talk to SIP and use your Google credentials to authenticate in their SIP Services.
• Which Codec is being used?
• G711 is the only one that I could trace, although the Plug-In indeed support iLBC and others. The reason behind it, is that G711 is a supported codec in most all PSTN, Media Gateway or other interconnection with Legacy Telecom. Alternatives would be transcode, which is out of the question due CPU load, drop of quality etc... Or use proprietary G729 which requires the payment of extremely high royalties per client/channel.
• Will they succeed in making money?
• Google "Cows" may produce some "milk", but I doubt Google consider that as an important income resource. The feature is much more related with PR and positioning about THE REALTIME company, than anything else. Having most of what Skype does in their closed client, in a browser and using open technologies is a direct confront to Skype's model. IMHO, Phone Numbers are dead, and will be ripped out of the market in less than 5 years from now. 
• Are the API for Audio/Video Streaming available for third-party usage?
• That I could not figure out. Tried document or formal info from Google without success. May someone could assist us on that matter with some Javascript reverse engineering, or a Google guy, that wanna share that with us. Please let us know :)
•  Is there any client supporting it already?
• No, it is not yet available in any client that I'm aware. But I bet that as soon Google appears with a formal specification and documentation, that will happen very very fast.

Thanks for all the questions, I hope I have answered most of it.

Google Call over Jingle with a SIP Gateway on their XMPP Server

I just confirmed in my Wireshark that Google Call on Gmail uses exactly what I recommended in a previous post back in 2009 when they acquired Gizmo5. And YES, it's Jingle!
Their wise choice of having a portable and extensive protocol(XMPP) as the bus and having specialized technologies like SIP, will grant them a flexibility never seen before on platform and device portability.
Their master plan is to be able to delivery mass market a cheap and alternative method for calling the old fashioned telephone numbers. And sure they have the right platform and tools in their hands:

Android

Almost all Android phones have with GTalk application pre-installed, which already runs a nice XMPP Client, besides other great alternatives like Nimbuzz.

Now imagine what Google can bring to the market without much effort due their choice of using Jingle extension of XMPP for their service? Google Call support on Android phones. That is the key and reason behind this service.



Overview Diagram:

Google Call on GMail

Google Call, as I mentioned before in a previous post, was added as a Calling feature direct to the browser.
I hope this take down Skype monopoly built on top of a closed and proprietary fuzzyware.

Google now has the most powerful position on VoIP world and soon will take down Skype eagerness for a proprietary/closed network.

Google's solution is built on top of a plugin, which is embedded on new Chrome and also easy to install on other browsers. They are using Standard XMPP and Jingle at Client Level with SIP in the backend, Streaming RTP with Standard Codecs directly from the browser. ( NO CRAP FLASH TRANSCODE USED! )

Google Call offer several advantages:

• Browser Based
• Open, so they can make use of third-party clients for it ( Do you need more reasons??? )
• VoIP everywhere, browser or in your favorite Client. Solid Model.

Hope Nimbuzz adds support for it soon!

You can try it here: http://www.google.com/chat/voice/


As you asked how it works:
Google is making use of recent acquired GIPS Company Technology to add native RTP streaming directly to the browser.
For PSTN Termination, Google is using Gizmo5, together with previous Google Voice partners.
I promise to post deeper technical information like protocol details and Codec later on.