Lucent winmodem need driver to work. Kppp is only humble servant, that mediates between functional modem and your ISP. It can't help you any other way. Nice site to start with is http://linmodems.technion.ac.il/

You can try this too http://distrowatch.com/2964 "new autodetected LT winmodems" it realy works out of the box, my personal experience. No driver, no nothing . Just in case... Modem is on /dev/modem not any of ttyS*. ttyS* are for external, serial modems.