@udaypette, you need to instal comgt formerly gcom, which is a data card control tool.
I am on Mandriva and this was the process:
* Go to control centre and authenticate as root
* Click on instal & remove software leads you to software management
* Click on communications to view available packages and check comgt
* Retrieve your installation cd and click apply after which you will be prompted to insert cd for installation.
* Once installion is complete restart machine and plug in modem
*Go to network centre and you will see edge/gprs option expand, refresh for machine to pick modem and configure
*Subsequent connections is network centre, ok for pre filled password, edge/gprs etc, refresh safaricom(modem name) connect.
Depending on your version of Linux you may need to look for equivalent steps.
"We do not inherit the earth from our ancestors, we borrow it from our children" Native American Proverb