International long-distance carrier Primus has completed the rollout of consumer and small business VoIP in the U.S., launching this week in 46 states a SIP-based service that undercuts the prices of both AT&T’s CallVantage and Vonage.

Primus has named the service Lingo and is charging a base rate of $19.95 a month for unlimited local, domestic long-distance calling as well as unlimited long-distance to Western Europe and Canada. While Primus soft-launched the service last month, it received approval to offer local phone numbers in all but four states this week.

Primus Co-President for the U.S. John Melick said that Primus envisions the service as both a primary line replacement service and as a second-line service, particularly for people who call Western Europe frequently. While it is charging a base rate of $20 for consumers and $80 for small businesses, Primus plans on expanding the service offerings in the coming year, adding new enhanced features and calling plans at different price points.

The new service is built off of Primus’s international VoIP backbone, which it had used until now to transport IP traffic for carriers and enterprises. As VoIP started gaining traction with the mass market, however, it was a logical decision to leverage the network for a consumer offer, Melick said.

"We have two clear advantages over our competitors," Melick said. "We have direct control over the quality of the service since we own our own infrastructure, and we have direct control over our own costs since we don’t have to go through other carriers."

For the time being though, Primus envisions Lingo as a small part of its overall business. A Fortune 1000 company, Primus traffics billions of minutes for its carrier and enterprise customers. Lingo will barely make a dent in network usage.

"That said, we do see VoIP as the wave of the future," Melick said. "Lingo is a small piece of our business now, but we don’t think it will always be."