unable to retrieve software information i don't have any internet connection
 

i am new to linux after installing centos 5.0 i checked out for modem the centos hasn't found that the modem is "motorola sm56 speakerphone modem"
the problems are i don't know which driver to download the driver page is this http://www.motorola.com/softmodem/sm56_download.htm and the second problem is when i try to install any rpm or try to open add remove its saying unable to retrieve software information as until the modem is made working condition i have no internet in my pc

centos is based on redhat so pick the largest of the redhats then go backwards if it fails