AT&T Call Blocking Attack Reveals Google Voice Structural Problem

AT&T's recent letter to the FCC about Google Voice was obviously disingenuous. It tried to link network neutrality, a key Google crusade, with Google Voice's blocking of certain calls. In reality, there was little connection except the politics involved: The real goal of the communication was to paint AT&T as on the side of network openness, and Google as on the opposite side. But the letter did inadvertently bring to light a potentially major weakness in the Google Voice model: the fact that the free service has to pay to have its users' calls delivered to their destinations on the PSTN (public switched telephone network).