I can understand that this is a classic problem with linux that it does not support even the hardware external modems. I have recently tried a USR External USB v 92 Modem (Model USR 5636). It has got its own DSP @56 Mhz, flash ram of 256 KBs and a EEPROM for upgrading the firmware.
With all these specifications, it is not even recognized by Red Hat Linux 9, Mandrake 10 and Fedora 2.
Has anybody tried this model before? If yes, is there any workaround to make it work under linux.