BOSTON -- Voice On the Net (VON) Coalition Conference -- EarthLink Inc. has been preparing for entry into the telephony market since the first of the year, and it now appears ready to pull the trigger with a Vonage-like replacement phone service it calls “Earthlink True Voice.”

In fact, it’ll be so much like Vonage Holdings Corp. service that Earthlink won’t need to resell Vonage service anymore. The ISP currently offers Vonage service branded with an “Earthlink Unlimited Voice” logo.

Vonage could not be reached for comment at press time.

Earthlink VP of voice services Steve Howe says his company intends to roll out the new service in selected markets in about two weeks. The service will then be offered to the rest of Earthlink’s 1.5 million broadband subscribers. Howe spoke at a Sonus Networks Inc. (Nasdaq: SONS) analyst luncheon at the VON show in Boston Wednesday.

Earthlink chose this week’s VON show to demonstrate that it has been busy doing the infrastructure and interconnection work needed to be a mass-market “replacement” service, which means VOIP phones can be used in place of traditional PSTN phone service. The ISP announced on Tuesday that it has a softswitch agreement with Sonus and has signed a PSTN interconnection agreement with Level 3 Communications Inc. (Nasdaq: LVLT). (See EarthLink Picks Sonus .)

Earthlink joins a growing parade of high-profile technology companies hustling to include IP telephony in their services menus. So far, these include Microsoft Corp. (Nasdaq: MSFT), Time Warner Inc.'s (NYSE: TWX) AOL division, Google (Nasdaq: GOOG), and eBay (Nasdaq: EBAY) -- and more are certain to come (see EBay Buys Skype for $2.6B, Google Talks the Talk, and AOL's Got VOIP Again ).

“Earthlink is not moving into voice, voice is moving into IP,” Howe says. “Voice is just another IP application now. “

But there’s more. Earthlink intends to leverage its existing broadband business by integrating it tightly with the new voice services. For instance, Howe says, users will access their email and voice mail at a single place on the Internet. “Over time we may decide to add in video, too."

That integration may be the edge Earthlink will need to take back some of the voice customers it sent Vonage’s way (see Vonage Exceeds One Mil ).

Earthlink also plans to roll out a line-powered residential phone service that will operate during a power outage, Howe says. The service will feature 8 Mbit/s of DSL2+ broadband bundled with unlimited calling for around $70. The new service will trial in Dallas, San Francisco, San Jose, and Seattle later this year.

— Mark Sullivan, Reporter, Light Reading