Call Hold and Waiting are powerful, basic features which are activated on almost all phones. They let you know who’s calling (even during a call) and place people on hold.
VAS Recommended FAQ
Most services are active by default. Call Hold and Call Waiting may require activation, using the following codes.
There are also codes listed to check.
Call Hold and Call Waiting
Activate Call Holding via SMS by sending VAS CH to 678.
You can also activate both of these services using the following codes:
Activation: *43# and SEND/OK
Deactivation: #43# and SEND/OK
Check whether services are active: *#43# and SEND/OK