I have a Dlink modem with Conexant chipset.The details of my modem are as follows:
Build Number : 4.10.2222

=====================================================================
= RESULT OF MODEM QUERY =
=====================================================================
NUMBER OF MODEMS FOUND = 1

MODEM #1:
PCI CONFIGURATION INFORMATION READ:
VENDOR ID : 127A
DEVICE ID : 1025
SUBVENDOR ID : 127A
SUBDEVICE ID : 1025
REVISION ID : 01

DEDUCED INFORMATION:
VENDOR NAME : ROCKWEL
DEVICE NAME : CHECK CHIPSET FOR CORRECT MODEM
SUBVENDOR NAME : UNKNOWN
MODEM TYPE : Check chipset for correct drivers
WINXP INBUILD SUPPORT : YES

This output is of Listmodem.The chipset is Conexant.I could not install my drivers in fedora core 3.Is there any free modem driver available

The short answer is: no

There is a driver from linuxant which also provides a fre version but the free version only allows 14kb instead of the full 56.