if this is the case then how can i manage to get connected through VSNL "without" any problem with the help of same telephone line. may be just things go in my favour in linux when i use dishnet.

The telephone network is circuit switched. Your "same telephone line" is only till the first exchange. Whenever you make a call, your call is routed through different exchanges depending where you call and the "telephone line" is different. Think of the line as a train, that takes different routes to different destinations, switching tracks at different junctions. Are you "Googly'd" by the "differents" yet!? ;-)

I had read a similar problem like yours in a PC mag Agony Nerd(C) column long time ago. The explanation that I gave you *is* what I read :-)

Fart