Network connection lost when receiving or making a call using Samsung Galaxy S2 Recently noticing that while making or receiving a call, the net connection on the Galaxy S2 is lost. Once the call is over, the connection is restored automatically. OS is android 2.3.6 (gingerbread). 

can anyone please help if it is a handset problem or any setting that needs to be updated.
This is absolutely normal. GSM connections cannot maintain a data and voice connection at the same time. The S2 can, and will, however be able to make a voice call and still continue using a WiFi data connection.

This is true for MOST cellular providers in India, UNLESS they support the DTM protocol (highly doubtful).