Any ATC Expert here to clarify CPDLC Process?

[arvindasija]

In Mumbai, the CPDLC message goes directly to the controller unlike the HF-radio message, which is received by the radio operator. The radio operator then sends the message by electronic means to the controller.

[Propellerhead]

Also need to make sure you have the correct tail number in the aircraft system manager. And correct call sign in the FMC otherwise won’t work.