1)first eject the windows driver CD of your modem from "terminal" or from "DISKS" (default,not automatic), then you can connect modem through network manager.
2)or use the software or .deb file provided with the modem (automatic, not default, not through network manager(nw) & you cannot use software center).
I advice to use the first one as it provides extra options like SMS, USSD, contacts, info, scan for networks through modem manager gui .
you can add your device id to usb mode switch for automatic eject as soon as you plugin your modem click here to add your device to usb mode switch
Hope this will help U
it is not real CD, just a popup memmory within the modem..
problem is that ubuntu defaultly allows you to use the nw not the .deb file provided by the manufacturer(so your driver CD is not allowed mounted on unity defaultly), for they use usb mode switch to eject the unmounted CD, which does not have id of your modem which is newer one to market click here to add your device to usb mode switch.
using default method is benefit only to users but newer modem gets unidentified and they have to manually add their device id to usb mode switch.
ubuntu 14.04 have updated list & it will automatically eject & you will your see your connection at nw.
Hope this helps U & please leave a comment