Phillip,
Now that I know what TFTP stands for... you realize that this is OBi forum
DSLR would be a much better place for broader VoIP issues. That said, I would use CallWithUs. You need to have a positive balance, but toll-free numbers are free. Given that I use CWU a lot for international calling, works well for me. YMMV, so there is no single answer!
