1.   That default carrier can generally verify the validity of a calling card from another carrier, like Verizon, but the rates will be sky-high.

2.   The representatives are Excel customers who have convinced friends, family members and acquaintances to switch their default long-distance carrier to Excel.

3.   Under the expected regulations, consumers could designate a new default carrier with one letter or a telephone call, much as American consumers can.

4.   Unlike companies such as Excel, which usually require users to switch their default long-distance carrier, the dial-around companies allow users to keep their provider.