Whatsapp doesn't work over 3G,everything else works fine
I faced similar problem until recently I found the fix. I use Vodafone 3G Pack.


If you are an android user, check the network and settings -> Access Point names
In that check if APN is set to Vodafone Live.
If yes, change it to default settings and it should be changed to vodafone Mobile connect.
Also, then check the value of MCC and MNC. It should be as per country code and mobile operator.


I didnt understand, why this changed on its own, but after making this change and rebooting phone, it worked for me.

I hope this works for you too..