AT&T has stepped up its campaign to convince the Federal Communications Commission to take on Google's Voice application, arguing once again that the search giant is guilty of a "double standard" on Net neutrality due to its call-blocking policy.

This afternoon, the telecom giant filed a letter with the FCC and provided it with a myth v. fact sheet rebutting Google's claim that the software application is a different class of service than what regulated phone companies offer.

The controversy stems from Google's (NASDAQ: GOOG) restriction on calls in certain rural areas, which it justifies on the grounds that local providers charge exorbitant rates to connect calls, often signing deals with adult-chat and conference-call services to drive up their fees. Google claims that those access costs are prohibitive to its free Voice service.

Further, Google has argued that because its service is a software application, it is exempt from the common carriage rules that govern companies like AT&T (NYSE: T).

Get the full story here at InternetNews.com.