See this link, and replace the APN address for Airtel.
http://linuxfornewbee.blogspot.com/
If you are using Ubuntu 9.04 or Ubuntu 9.10, then use Network-Manager to
configure internet connection. also for Fedora 11& 12.
--
Padhu,
Pollachi.
Knowledge is power !
"Be an Energy (Opti)mizer - Use Electricity Wiser"