Technical answer to your question is YES
Practical answer is NO, you will experience a lot of choppy unclear voice experience. If you want to enjoy the freedom of VoIP, better to upgrade your internet connection.
Also do a VoIP speed test on your existing connection and copy paste the results here so that technical people from VOIPO can give some correct advise.
http://myspeed.visualware.com/indexvoip.php
Click on North America and from the next screen select any YELLOW pin that is close to your location.
Once the test is done, Click on the Graph tab from the test results, and within that box you will find "Click here for detailed analysis", click on it. A new page will be opened with your test results.
Just copy the first part of results here excluding your IP address.
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