In a message dated 6/19/2002, Alex McNeil writes:
> For the PSTN analogue modems I am not so sure: > FCC Part 68 vs CTR21 (TBR21)? > Can anyone offer some advice here? > I assume if the product meets CTR21 then the modem should function OK in > Italy? > Does Italy have other modem details that I should know about? > Hi Alex: If you modem was not designed to meet CTR 21, it will probably fail the CTR 21 tests for current limiting and for transient response. Fortunately, CTR 21 is no longer a mandatory requirement under the RTTE directive. The main regulatory requirements that apply are those for safety and EMC. Regarding general compatibility with the Italian network, keep in mind that dial tone in Italy is cadenced, so your North American dial tone detector may not properly detect it. As far as the other parameters are concerned, it is hard to say with certainty without reviewing the actual design. Since FCC Part 68 is a harms-based standard, the tests are only intended to show that the equipment will not harm the public network. It is not necessary for the equipment to actually function at all, even on the North American network. That being said, I do think that a well designed modem intended for North America is likely to operate reasonably well on the Italian network, provided that the cadenced dial tone does not present a problem. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
