In response to an inquiry from the Federal Communications Commission, Google said that its voice service isn't blocking as many calls as in the past.

"Google Voice now restricts calls to fewer than 100 specific phone numbers, all of which we have good reason to believe are engaged in traffic pumping schemes," telecom counsel Richard Whitt wrote on the policy blog.

The FCC launched an investigation of Google Voice earlier this month, after AT&T complained that Google was violating net neutrality principles as well as regulations requiring telecoms to connect all calls.

Google acknowledged blocking calls to some rural exchanges, but said it did so because it couldn't afford to offer the service for free otherwise. Some rural telcos charge other carriers very high rates -- up to 100 times more than large local phone companies -- to connect calls coming from long-distance or wireless numbers.

In its letter this week to the FCC, Google said that it began blocking calls in August, after noticing that the top ten prefixes (area code and the first three digits of a phone number) accounted for a disproportionate share of traffic and of costs. Whitt said that Google initially blocked calls to high-cost destinations, but now only restricts calls to specific numbers.

Google also argues that it's not a traditional telecom, and therefore, rules against blocking don't apply. The company also takes the position that net neutrality rules only apply to Internet service providers, and not companies that create Web-based software apps.

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