To tell the truth, I don't know personally of any modems that have both CCITT
and Bell standards for 300 and 1200 baud communication…In 2400-baud,
nowadays ALL 2400-baud modems use CCITT V.22 bis standards..So if you
communicate at 2400 all the time, there will be no compatibility problems.
At the lower baudrates, though, you may need two modems. Again, this is NOT
absolute…am NOT a hardware man..and there may very well be modems that do
both…but I shudder to think of the price, since such modems would be for a
specialized market.