Google’s Click-to-Call beta yesterday is generating some interesting comment about the nature of VoIP over on Om Malik’s site. I’m sure that Google is terminating the calls on PSTN handsets, because the vast majority of the customers wanting to use the service do not yet have VoIP softphones, and may never have softphones. Wireless phones are ubiquitous.
Caveat: I do not know the way that Google’s system is built. But, if I were going to build it, I would do the following:
Use a VoIP application server and softswitch to manage the traffic. It’s by far the least expensive to build out, and the fastest way to get a service into market.
Write a Click-to-Call server (it could be as simple as a CGI script!) to convert those clicked links into signalling requests to call two end points on the network — one at the advertiser, and one at the prospect.
Route the traffic using an IP backbone provider like Level3 to a destination gateway. At the gateway closest to each of the PSTN numbers given, drop the call onto the local class 5 switch.
That’s how you eliminate the long distance. You could do the same within the existing PSTN network , it’s worth noting, by hosting the Click-to-Call application on a Service Control Point. It’s more expensive and would take longer to deploy, but it could be done. All VoIP does is eliminate the long distance tolls.
The next obvious upgrade would be to route the call to an IP client in the advertisers business (they’re more likely to have an IP PBX than the prospect is to have a softclient on the desktop).
And finally, the last upgrade might be to route the call to to IP client on the prospects desktop.
With VoIP peering arrangements you can accomplish the last step completely transparently. In my every day use of the phone, I have a number with Unlimitel which takes any calls people make to me from the PSTN, and turns them into VoIP traffic. I use the Iotum Relevance engine to route all my desk calls to the softphone on my desktop PC, to my cell phone when I am not at my desk, and to PhoneGnome when I am at home. My perspective — I am a VoIP user, who occasionally sends my calls to a PSTN device, which is my old cell phone.
VoIP’s already widespread, even if it’s not on every desktop.
UPDATE: Venkatash Rangarajan has a very detailed look at how to build a Google-like Click-to-Call system on his blog.