AT&T has complained in a new deposition (PDF) to the Federal Communications Commission (FCC) that the Google Voice application does not follow the "free and open" principles towards which the FCC is working.
The telecoms company argues that the way in which Google Voice cuts off some local exchanges owing to the fees they charge is more serious than the search giant is letting on.
AT&T cites research claiming to show that Google Voice has cut off an ambulance service, a church, a tax preparation service, a tribal community college and a convent of Benedictine nuns, as well as the campaign office of a member of the US House of Representatives, among others.
"Google's practice of blocking Google Voice calls demonstrates exactly why any open internet principles must also apply even-handedly to providers of internet applications, content and services," said Robert Quinn, AT&T's federal regulatory senior vice president.
"If, as Google claims, it is allowed to block whichever Google Voice calls it wants, and the FCC is powerless to stop it, Google can also block whichever internet sites, applications, services or content it wants, and the FCC cannot do anything about that either."
AT&T also raised questions about the impartiality of Google's search results, citing research claiming that the search firm is raising the ranking of companies that support net neutrality in its paid listings slots.
The FCC initially began in investigation into why Google Voice was banned from Apple's App Store, but has now widened the scope of the investigation into examining the Google Voice application itself.
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