Today we cover an announcement from AT&T: The company will offer its smartphone customers a free mobile VoIP app -- providing international long distance calling at competitive rates with its latest AT&T Call International service. The AT&T Call International app is available today as a free download from the Android Market and BlackBerry AppWorld. 

The app is designed to give AT&T wireless subscribers another alternative to stay in touch with family and friends abroad. AT&T Call International was developed in cooperation with and is operated by 8x8 Inc. 8x8 also offers cloud communications services including VoIP business phone services, audio and video conferencing, hosted contact center and unified communications (UC) solutions. 

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Using the app, AT&T smartphone customers can make calls from the U.S. to international numbers, and when abroad, customers will benefit from the same rates using the app over Wi-Fi. When placing an international call from the U.S. the app uses the AT&T network to initiate the call. Internationally, the lower rates only apply when using Wi-Fi: If not on a Wi-Fi network, users will be charged the normal international roaming rate and not get the benefit of the lower service rates.

When dialing internationally from the U.S., Puerto Rico or the U.S. Virgin Islands, the call starts on the AT&T wireless network as a domestic call so calling minutes are accrued. Using that domestic routing number, the call is then completed to the international destination dialed using AT&T Call International. When using the device internationally over a Wi-Fi network, users are not getting charged for voice minutes because the call is not originating on the AT&T voice network. 

The app provides step-by-step instructions to establish an AT&T Call International account. Once established, customers can immediately make international calls through the app by either dialing directly or by accessing their existing contacts list. All calls are billed directly to the customer's credit card. Countries and rates are available at www.att.com/callinternational. 

Our observation: Several carriers offer a way to reduce international calling rates using VoIP/IP in tandem with a mobile phone including Verizon (in a partnership with Skype announced here over a year ago), Vonage (covered in this newsletter last month), and a company called ChatTime that we’ll look at in our next newsletter.  

Read more about voip & convergence in Network World's VoIP & Convergence section.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Larry Hettick is a principal analyst at Current Analysis.