Originally Posted by Mohammad Danish
How can we use nokia phone as modem via bluetooth in linux
Since you don't tell us what version/distro of Linux, what kind of Nokia phone, what desktop environment, what your mobile provide allows, and what kind of hardware you're using Linux ON, what do you think we'll be able to tell you??
Short answer: you need to use rfcomm and hcitool to bind your bluetooth device to a device. From there, set up your dialer to use it. This thread:
...has info on how to configure a bluetooth device to be bound to a 'real' device.