BSNL provides a facility that lets you receive incoming calls even when your telephone is busy. You will get a short duration pip-pip tone when you are busy talking , indicating that another call is waiting for you , provided you have activated this facility. You can talk to any one of the callers keeping the other waiting. Complete secrecy of communication between the two callers is maintained. This facility is available for free for all BSNL users.
Procedure for activation/deactivation:
- Dial 118 and get the acceptance tone similar to the engage tone but with a longer gap between the beeps.
- Dial 119 and get the acceptance tone. [source]