It more likely could be an ISP problem. Change the MTU for your interface to 1400 and then try. To change the MTU simple do a:
$ ifconfig ethX mtu 1400
if it works, experiment with different values (usually 1440 would be the limit) Once you find something that works, change the setting in NetworkManager to make it persistent.
A lot of Indian ISPs seem to have this problem. It is either due to incompetent admins, el cheapo equipment, limitations of the connection medium or all of those things.
Let us know if it works.
cheers,
Hi Steve, Yup, i alter the mtu as suggested, but it doesn't work either. Thanks for reply.
Regards, Ayush hakmn.blogspot.com